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slightly OT: etching the OD of a cylinder to create a graduated dial

slightly OT: etching the OD of a cylinder to create a graduated dial

2013-03-15 by Rick Sparber

This has been a favorite problem of mine for a long time.



It is standard practice to engrave the outside diameter of a cylinder with
tick marks and numbers in order to make a graduated dial. I have done this
by laser printing, mirror image, to clear plastic and then bolting it on the
OD with the toner on the inside:



http://rick.sparber.org/Articles/CD/CDM/d.pdf



It is fairly rugged but not as nice as engraving. I've always thought that
chemical etching would be idea.



I'm not interested in super expensive methods or ones requiring more than
average skill. Sure CNC can do this task, so can a laser cutter. Maybe
Wal-Mart sells them. No fun there.



One idea that I just thought of uses a previously engraved dial. I would
turn a cylinder with the same OD as the dial. Then I would fill the grooves
in the dial with softened paraffin wax and strike off so the rest of the
surface is wax free. Then I would chill this dial while heating the cylinder
to be etched. By rolling them together, I hope to transfer the wax from dial
to cylinder. If that works, the etching process should be easy. I realize
this generates raised features rather than recesses but that might actually
be better. Since something like this works for printing, maybe there is
reason for hope here.



Has anyone tried this? Any warnings or suggestions?



Thanks,



Rick



[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] slightly OT: etching the OD of a cylinder to create a graduated dial

2013-03-15 by KeepIt SimpleStupid

I used to use concentrated HF at work routinely. Later we had to be specifically certified to work with HF. It's very nasty stuff. I looked at amazon and there are a number of etching products, for porcelin. http://www.amazon.com/s/?ie=UTF8&keywords=hydrofluoric+acid&tag=googhydr-20&index=aps&hvadid=22879189327&hvpos=3o2&hvexid=&hvnetw=g&hvrand=1455058631626177776&hvpone=&hvptwo=&hvqmt=e&ref=pd_sl_2yx2giqcys_e

I searched for Hydrofloric Acid (HF). HF cannot be stored in a glass bottle.

I bought a gallon of stuff that contained 3% HF and 3% Hydrochloric, a commercial product for cleaning windows. I accidentally got some Superclean on the house windows. It seems to etch it, but it worked wonders. I only needed a little bit, but it beat replacing the windows. Every once and a while I use it to clean some bottles used to store iced tea. Takes less than 30 sec to clean the bottle. I have to find some way to use it. Disposal would really be an issue, (neutralizing with baking soda, but ph testing would be worthwhile.

--- On Fri, 3/15/13, Rick Sparber <rgsparber@...> wrote:

From: Rick Sparber <rgsparber@...>
Subject: [Homebrew_PCBs] slightly OT: etching the OD of a cylinder to create a graduated dial
To: Homebrew_PCBs@yahoogroups.com
Cc: "'Granthams'" <granthams@...>
Date: Friday, March 15, 2013, 11:08 AM


























This has been a favorite problem of mine for a long time.



It is standard practice to engrave the outside diameter of a cylinder with

tick marks and numbers in order to make a graduated dial. I have done this

by laser printing, mirror image, to clear plastic and then bolting it on the

OD with the toner on the inside:



http://rick.sparber.org/Articles/CD/CDM/d.pdf








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[Non-text portions of this message have been removed]

calcium carbonate, HF acid...

2013-03-15 by smilingcat90254

Calcium carbonate for that matter most carbonate will react with even trace amount of hydrochloric acid remaining in your etchant. And yes it will foam because CO2 is being released in the reaction. So if your solution keeps foaming keep adding the carbonate. It will neutralize the acid for safe disposal.

Reaction of Copper chloride and Calcium carbonate probably will be much slower than Copper chloride and sodium carbonate. But it should work. not 100% plus sure.

**** HF acid ****
I was in semiconductor manufacturing business so I'm quite aware of HF acid. Very dangerous stuff. No you can not store in a glass. It will etch glass. No you can not store in stainless steel container!!

HF chemical burn is severe even at low concentration. It will penetrate bare skin and the flourine ion will interact with the calcium in your bone. HF will dissolve your bone under all the tissue.

I didn't think you can buy it unless you can show you are a business or a researcher of some sort.

Re: [Homebrew_PCBs] calcium carbonate, HF acid...

2013-03-16 by Roland Harriston

wow!

You dudes play around with some very nasty stuff just to etch a printed
circuit!

Or, maybe this thread is just a sort of "pissing contest" to show off that
the participants have had Chem 101 at a community college.

Pardon my cynicism, but I just don't get the drift.

Keep it simple..........keep it safe.

Roland F. Harriston, P.D.
***************************

On 3/15/2013 4:16 PM, smilingcat90254 wrote:
>
> Calcium carbonate for that matter most carbonate will react with even
> trace amount of hydrochloric acid remaining in your etchant. And yes
> it will foam because CO2 is being released in the reaction. So if your
> solution keeps foaming keep adding the carbonate. It will neutralize
> the acid for safe disposal.
>
> Reaction of Copper chloride and Calcium carbonate probably will be
> much slower than Copper chloride and sodium carbonate. But it should
> work. not 100% plus sure.
>
> **** HF acid ****
> I was in semiconductor manufacturing business so I'm quite aware of HF
> acid. Very dangerous stuff. No you can not store in a glass. It will
> etch glass. No you can not store in stainless steel container!!
>
> HF chemical burn is severe even at low concentration. It will
> penetrate bare skin and the flourine ion will interact with the
> calcium in your bone. HF will dissolve your bone under all the tissue.
>
> I didn't think you can buy it unless you can show you are a business
> or a researcher of some sort.
>
>



[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] calcium carbonate, HF acid...

2013-03-16 by KeepIt SimpleStupid

--- On Fri, 3/15/13, Roland Harriston <rolohar@...> wrote:

From: Roland Harriston <rolohar@...>
Subject: Re: [Homebrew_PCBs] calcium carbonate, HF acid...
To: Homebrew_PCBs@yahoogroups.com
Date: Friday, March 15, 2013, 9:29 PM


























wow!



You dudes play around with some very nasty stuff just to etch a printed

circuit!



Or, maybe this thread is just a sort of "pissing contest" to show off that

the participants have had Chem 101 at a community college.



Pardon my cynicism, but I just don't get the drift.



Keep it simple..........keep it safe.



Roland F. Harriston, P.D.

***************************

This all started because someone wanted to etch glass. HF was just one of the nasties I got to play with. What I did was etched quartz tubes in HF, put red phosphorous and Zinc in them and sealed them under vacuum. We then put the tube in a furnace with a heating profile over days and hoped it didn't explode while reacting. Others got to play with Silane, phosphene and a lot of other Hydride gasses. I got to design the safety system. I got to routinely fix high voltage regulators such as a 30 KW electron gun with a 15 kVDC 1 A tube shunt regulated power supply and an X-ray set with a 100 kV at 0.1 A DC power supply and a 1 KW RF power supply. No one else did, but me. We still thought the table saw in the shop was the most dangerous piece of equipment followed by the 5 HP engine lathe. One little piece of equipment would use 70 A 208 V 3-phase power. Ouch! Yep, Be safe or don't try this at home.























[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] calcium carbonate, HF acid...

2013-03-16 by Harvey White

On Fri, 15 Mar 2013 18:29:06 -0700, you wrote:

>wow!
>
>You dudes play around with some very nasty stuff just to etch a printed
>circuit!

The three most common chemicals are:

1) ferric chloride. may or may not be readily available, electronics
wise, hard to find. Last price I saw was USD 30/gallon and that was
many years ago. It's ferric chloride and some HCL. Main problem with
it is opacity, lack of regeneration, cost, and it stains everything in
sight. Use it warm.

2) xxx persulphate, generally potassium or ammonium persulphate. Needs
to be used warm. Clear and turns into blue clear as it etches, one
source is pool chemicals, but only 32% is active ingredient and the
rest is "additives". It will work, but a batch in the tank that I
have costs 10 USD/session and I don't think it lasts.

3) copper chloride: start off with drugstore H2O2 and muriatic acid.
As long as you handle the acid well, there's no problem that I've
seen. Once the H2O2 goes flat (with etching and with time), you have
CuCl etchant which lasts practically forever. Regenerate with HCL,
use with bubbled air and use warm. Cost? Perhaps 5 USD/gallon or so,
and considering that it lasts forever, I'd say a good choice.

I used ferric chloride for years, I can show you stained driveways to
prove it.

I switched over to the copper chloride (probably cupric chloride, but
I don't pretend to be a chemist) a while back and will avoid the
ferric chloride from now on.

I'd use the persulphate etchant if I could get a decent supply of the
chemical, it would be a "use once" and discard. Not sure exactly how
to get rid of it, though. Problem is not the etchant, it's the copper
in the etchant.

just my opinions, though.

Harvey

>
>Or, maybe this thread is just a sort of "pissing contest" to show off that
>the participants have had Chem 101 at a community college.
>
>Pardon my cynicism, but I just don't get the drift.
>
>Keep it simple..........keep it safe.
>
>Roland F. Harriston, P.D.
>***************************
>
>On 3/15/2013 4:16 PM, smilingcat90254 wrote:
>>
>> Calcium carbonate for that matter most carbonate will react with even
>> trace amount of hydrochloric acid remaining in your etchant. And yes
>> it will foam because CO2 is being released in the reaction. So if your
>> solution keeps foaming keep adding the carbonate. It will neutralize
>> the acid for safe disposal.
>>
>> Reaction of Copper chloride and Calcium carbonate probably will be
>> much slower than Copper chloride and sodium carbonate. But it should
>> work. not 100% plus sure.
>>
>> **** HF acid ****
>> I was in semiconductor manufacturing business so I'm quite aware of HF
>> acid. Very dangerous stuff. No you can not store in a glass. It will
>> etch glass. No you can not store in stainless steel container!!
>>
>> HF chemical burn is severe even at low concentration. It will
>> penetrate bare skin and the flourine ion will interact with the
>> calcium in your bone. HF will dissolve your bone under all the tissue.
>>
>> I didn't think you can buy it unless you can show you are a business
>> or a researcher of some sort.
>>
>>
>
>
>
>[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] calcium carbonate, HF acid...

2013-03-16 by lists

In article <ki0a4k+97dv@...>,
smilingcat90254 <smilingcat@...> wrote:

> I didn't think you can buy it unless you can show you are a business or
> a researcher of some sort.

I would have thought so too but:

http://www.ebay.co.uk/itm/221076919283;jsessionid=82E321963BB9E53F072A8A74948A4D2A?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_sacat%3D0%26_nkw%3D221076919283%26_rdc%3D1

IF the link doesn't work search for item 221076919283

Better make sure you have plenty of this:

http://www.sellesmedical.co.uk/store/product/322-HF-Antidote-Gel-Calcium-Gluconate-25g-

--
Stuart Winsor

Only plain text for emails
http://www.asciiribbon.org

Re: calcium carbonate, HF acid...

2013-03-18 by AlienRelics

OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat hijacks keepitsimplestupid's hijacked thread. Interesting.

For those of us who are not chemists, what is HF acid?

Steve Greenfield AE7HD

--- In Homebrew_PCBs@yahoogroups.com, "smilingcat90254" <smilingcat@...> wrote:
>
> Calcium carbonate for that matter most carbonate will react with even trace amount of hydrochloric acid remaining in your etchant. And yes it will foam because CO2 is being released in the reaction. So if your solution keeps foaming keep adding the carbonate. It will neutralize the acid for safe disposal.
>
> Reaction of Copper chloride and Calcium carbonate probably will be much slower than Copper chloride and sodium carbonate. But it should work. not 100% plus sure.
>
> **** HF acid ****
> I was in semiconductor manufacturing business so I'm quite aware of HF acid. Very dangerous stuff. No you can not store in a glass. It will etch glass. No you can not store in stainless steel container!!
>
> HF chemical burn is severe even at low concentration. It will penetrate bare skin and the flourine ion will interact with the calcium in your bone. HF will dissolve your bone under all the tissue.
>
> I didn't think you can buy it unless you can show you are a business or a researcher of some sort.
>

Re: etching the OD of a cylinder to create a graduated dial

2013-03-18 by AlienRelics

Metal etching is on topic.

What about a stepper motor? 200 steps per revolution. Or if that is not fine enough, bring that down with toothed belt and pulleys?

Steve Greenfield AE7HD


--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:
>
> This has been a favorite problem of mine for a long time.
>
>
>
> It is standard practice to engrave the outside diameter of a cylinder with
> tick marks and numbers in order to make a graduated dial. I have done this
> by laser printing, mirror image, to clear plastic and then bolting it on the
> OD with the toner on the inside:
>
>
>
> http://rick.sparber.org/Articles/CD/CDM/d.pdf
>
>
>
> It is fairly rugged but not as nice as engraving. I've always thought that
> chemical etching would be idea.
>
>
>
> I'm not interested in super expensive methods or ones requiring more than
> average skill. Sure CNC can do this task, so can a laser cutter. Maybe
> Wal-Mart sells them. No fun there.
>
>
>
> One idea that I just thought of uses a previously engraved dial. I would
> turn a cylinder with the same OD as the dial. Then I would fill the grooves
> in the dial with softened paraffin wax and strike off so the rest of the
> surface is wax free. Then I would chill this dial while heating the cylinder
> to be etched. By rolling them together, I hope to transfer the wax from dial
> to cylinder. If that works, the etching process should be easy. I realize
> this generates raised features rather than recesses but that might actually
> be better. Since something like this works for printing, maybe there is
> reason for hope here.
>
>
>
> Has anyone tried this? Any warnings or suggestions?
>
>
>
> Thanks,
>
>
>
> Rick
>
>
>
> [Non-text portions of this message have been removed]
>

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-18 by David

HF acid is hydrogen fluoride dissolved in water just like HCl acid is
hydrogen chloride dissolved in water. The hydrochloric acid is just a
nuisance if you are exposed compared to hydrofluoric acid. The later
requires significant safety precautions and really should be avoided
if possible.

On Mon, 18 Mar 2013 21:39:17 -0000, "AlienRelics"
<alienrelics@...> wrote:

>OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat hijacks keepitsimplestupid's hijacked thread. Interesting.
>
>For those of us who are not chemists, what is HF acid?
>
>Steve Greenfield AE7HD
>
>--- In Homebrew_PCBs@yahoogroups.com, "smilingcat90254" <smilingcat@...> wrote:
>>
>> Calcium carbonate for that matter most carbonate will react with even trace amount of hydrochloric acid remaining in your etchant. And yes it will foam because CO2 is being released in the reaction. So if your solution keeps foaming keep adding the carbonate. It will neutralize the acid for safe disposal.
>>
>> Reaction of Copper chloride and Calcium carbonate probably will be much slower than Copper chloride and sodium carbonate. But it should work. not 100% plus sure.
>>
>> **** HF acid ****
>> I was in semiconductor manufacturing business so I'm quite aware of HF acid. Very dangerous stuff. No you can not store in a glass. It will etch glass. No you can not store in stainless steel container!!
>>
>> HF chemical burn is severe even at low concentration. It will penetrate bare skin and the flourine ion will interact with the calcium in your bone. HF will dissolve your bone under all the tissue.
>>
>> I didn't think you can buy it unless you can show you are a business or a researcher of some sort.

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-18 by "Zoran A. Šćepanović"

On 03/18/2013 10:39 PM, AlienRelics wrote:
> OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat hijacks keepitsimplestupid's hijacked thread. Interesting.
>
> For those of us who are not chemists, what is HF acid?
>
> Steve Greenfield AE7HD
>

HydroFluoric acid :-)

--
Best Regards,
Q Systems
Zoran A. Šćepanović
zastos@...
Skype: zoran.a.scepanovic
http://zastos.com
+381 63 609-993

-..-
The greatest enemy of the neck is the tongue.

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-18 by Todd F. Carney / K7TFC

Google "hf acid." The very first item on the page--big as life--will answer
your question and tell you all about it. Oh, I'm not a chemist, either. I'm
just a guy of normal intelligence who knows how to use a web browser. I
also know better than to broadcast my stupidity for intelligent people to
see.

Sorry about this peevish (look that up, too) response, but this kind of
"Okay, *Einstein*, what does that big fancy word mean, anyway?" attitude
really bugs me. I actually think it's mostly trolls who do this kind of
thing, so it's just one more thing to ignore.

I must be in a "mood." I guess I better go solder something together.

73,

Todd
------------------------------------------------------------------------------------
K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
------------------------------------------------------------------------------------
QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design


On Mon, Mar 18, 2013 at 2:39 PM, AlienRelics <alienrelics@...> wrote:

> **
>
>
> OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat hijacks
> keepitsimplestupid's hijacked thread. Interesting.
>
> For those of us who are not chemists, what is HF acid?
>
> Steve Greenfield AE7HD
>
> --- In Homebrew_PCBs@yahoogroups.com, "smilingcat90254" <smilingcat@...>
> wrote:
> >
> > Calcium carbonate for that matter most carbonate will react with even
> trace amount of hydrochloric acid remaining in your etchant. And yes it
> will foam because CO2 is being released in the reaction. So if your
> solution keeps foaming keep adding the carbonate. It will neutralize the
> acid for safe disposal.
> >
> > Reaction of Copper chloride and Calcium carbonate probably will be much
> slower than Copper chloride and sodium carbonate. But it should work. not
> 100% plus sure.
> >
> > **** HF acid ****
> > I was in semiconductor manufacturing business so I'm quite aware of HF
> acid. Very dangerous stuff. No you can not store in a glass. It will etch
> glass. No you can not store in stainless steel container!!
> >
> > HF chemical burn is severe even at low concentration. It will penetrate
> bare skin and the flourine ion will interact with the calcium in your bone.
> HF will dissolve your bone under all the tissue.
> >
> > I didn't think you can buy it unless you can show you are a business or
> a researcher of some sort.
> >
>
>
>


[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-19 by Roland Harriston

On 3/18/2013 2:39 PM, AlienRelics wrote:
>
> OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat
> hijacks keepitsimplestupid's hijacked thread. Interesting.
>
> For those of us who are not chemists, what is HF acid?
>
> Steve Greenfield AE7HD
>
> -
>
Trust me.
You are better-off not knowing what it is.
Much, much better-off not ever trying to use it.
Good stuff to stay away from.

Roland F. Harriston, P.D.
***********************


[Non-text portions of this message have been removed]

Re: calcium carbonate, HF acid...

2013-03-19 by tda7000

I think it's much better to know what something is, how dangerous and why, so then you'll know exactly why and how you can avoid it.

Give people only half the facts or try to keep everyone in the dark and you have a recipe for disaster, in my opinion. But maybe that's just me...


--- In Homebrew_PCBs@yahoogroups.com, Roland Harriston <rolohar@...> wrote:
>
> On 3/18/2013 2:39 PM, AlienRelics wrote:
> >
> > OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat
> > hijacks keepitsimplestupid's hijacked thread. Interesting.
> >
> > For those of us who are not chemists, what is HF acid?
> >
> > Steve Greenfield AE7HD
> >
> > -
> >
> Trust me.
> You are better-off not knowing what it is.
> Much, much better-off not ever trying to use it.
> Good stuff to stay away from.
>
> Roland F. Harriston, P.D.
> ***********************
>
>
> [Non-text portions of this message have been removed]
>

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-19 by Duane C. Johnson

HF

Hydrofluoric acid

Really wicked and useful stuff.

http://en.wikipedia.org/wiki/Hydrofluoric_acid

Duane

--
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http://www.redrok.com/led3xassm.htm [*]
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RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-19 by Rick Sparber

Steve,

How would the stepper fit into my plan to etch the dial?

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of AlienRelics
Sent: Monday, March 18, 2013 2:44 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

Metal etching is on topic.

What about a stepper motor? 200 steps per revolution. Or if that is not fine
enough, bring that down with toothed belt and pulleys?

Steve Greenfield AE7HD


--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:
>
> This has been a favorite problem of mine for a long time.
>
>
>
> It is standard practice to engrave the outside diameter of a cylinder
> with tick marks and numbers in order to make a graduated dial. I have
> done this by laser printing, mirror image, to clear plastic and then
> bolting it on the OD with the toner on the inside:
>
>
>
> http://rick.sparber.org/Articles/CD/CDM/d.pdf
>
>
>
> It is fairly rugged but not as nice as engraving. I've always thought
> that chemical etching would be idea.
>
>
>
> I'm not interested in super expensive methods or ones requiring more
> than average skill. Sure CNC can do this task, so can a laser cutter.
> Maybe Wal-Mart sells them. No fun there.
>
>
>
> One idea that I just thought of uses a previously engraved dial. I
> would turn a cylinder with the same OD as the dial. Then I would fill
> the grooves in the dial with softened paraffin wax and strike off so
> the rest of the surface is wax free. Then I would chill this dial
> while heating the cylinder to be etched. By rolling them together, I
> hope to transfer the wax from dial to cylinder. If that works, the
> etching process should be easy. I realize this generates raised
> features rather than recesses but that might actually be better. Since
> something like this works for printing, maybe there is reason for hope
here.
>
>
>
> Has anyone tried this? Any warnings or suggestions?
>
>
>
> Thanks,
>
>
>
> Rick
>
>
>
> [Non-text portions of this message have been removed]
>




------------------------------------

Be sure to visit the group home and check for new Links, Files, and Photos:
http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-19 by Roland Harriston

I agree:

But, yet, I wonder about people who will not or cannot use Google (at
this stage of the game)
to independently look something up. and not broadcast to the entire
world-wide web that they don't know what something is.
HF acid is not that exotic.

Pardon my snark, but if you are messing around with this kind of stuff,
"Google-ing"
should be old hat.

Roland F. Harriston, P.D.
**********************



On 3/18/2013 5:56 PM, tda7000 wrote:
>
> I think it's much better to know what something is, how dangerous and
> why, so then you'll know exactly why and how you can avoid it.
>
> Give people only half the facts or try to keep everyone in the dark
> and you have a recipe for disaster, in my opinion. But maybe that's
> just me...
>
> --- In Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>, Roland Harriston
> <rolohar@...> wrote:
> >
> > On 3/18/2013 2:39 PM, AlienRelics wrote:
> > >
> > > OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat
> > > hijacks keepitsimplestupid's hijacked thread. Interesting.
> > >
> > > For those of us who are not chemists, what is HF acid?
> > >
> > > Steve Greenfield AE7HD
> > >
> > > -
> > >
> > Trust me.
> > You are better-off not knowing what it is.
> > Much, much better-off not ever trying to use it.
> > Good stuff to stay away from.
> >
> > Roland F. Harriston, P.D.
> > ***********************
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>



[Non-text portions of this message have been removed]

Re: calcium carbonate, HF acid...

2013-03-19 by tda7000

True, I guess that's what lmgtfy.com is for ;)

--- In Homebrew_PCBs@yahoogroups.com, Roland Harriston <rolohar@...> wrote:
>
> I agree:
>
> But, yet, I wonder about people who will not or cannot use Google (at
> this stage of the game)
> to independently look something up. and not broadcast to the entire
> world-wide web that they don't know what something is.
> HF acid is not that exotic.
>
> Pardon my snark, but if you are messing around with this kind of stuff,
> "Google-ing"
> should be old hat.
>
> Roland F. Harriston, P.D.
> **********************
>
>
>
> On 3/18/2013 5:56 PM, tda7000 wrote:
> >
> > I think it's much better to know what something is, how dangerous and
> > why, so then you'll know exactly why and how you can avoid it.
> >
> > Give people only half the facts or try to keep everyone in the dark
> > and you have a recipe for disaster, in my opinion. But maybe that's
> > just me...
> >
> > --- In Homebrew_PCBs@yahoogroups.com
> > <mailto:Homebrew_PCBs%40yahoogroups.com>, Roland Harriston
> > <rolohar@> wrote:
> > >
> > > On 3/18/2013 2:39 PM, AlienRelics wrote:
> > > >
> > > > OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat
> > > > hijacks keepitsimplestupid's hijacked thread. Interesting.
> > > >
> > > > For those of us who are not chemists, what is HF acid?
> > > >
> > > > Steve Greenfield AE7HD
> > > >
> > > > -
> > > >
> > > Trust me.
> > > You are better-off not knowing what it is.
> > > Much, much better-off not ever trying to use it.
> > > Good stuff to stay away from.
> > >
> > > Roland F. Harriston, P.D.
> > > ***********************
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
>
>
>
> [Non-text portions of this message have been removed]
>

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-19 by Mitch Davis

On Tue, Mar 19, 2013 at 5:56 AM, Todd F. Carney / K7TFC <k7tfc@...> wrote:
>
> I also know better than to broadcast my stupidity for intelligent people to
> see.

Q: What's the difference between HF and Todd F. Carney?

A: One is acidic, and the the other is a caustic :-)

Sorry, couldn't resist.

Having said that, I've thought for a long while that the folk in this
group are a little strange. Obviously highly intelligent yet at the
same time missing something, some awareness of what the rest of the
electronic world is doing. A kind of collective Aspergers perhaps.
That's by no means a value judgement of good or bad, just seems...
different. You guys are marching to the beat of a different drummer.

Mitch.

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-19 by Rick Sparber

Mitch,

There are many ways to engrave and/or stamp dials. I'm looking for a way to do it with etching. My goal is not the dial but rather a new method.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Mitch Davis
Sent: Tuesday, March 19, 2013 7:50 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

On Tue, Mar 19, 2013 at 10:51 AM, Rick Sparber <rgsparber@...> wrote:
>
> How would the stepper fit into my plan to etch the dial?

Maybe the stepper could rotate the cylinder and a tool could carve the graduations. Etch, carve, as long as you end up with the graduations
:-)

Mitch.

Re: calcium carbonate, HF acid...

2013-03-19 by Todd Carney / K7TFC

--- In Homebrew_PCBs@yahoogroups.com, Mitch Davis <mjd@...> wrote:
>
> Q: What's the difference between HF and Todd F. Carney?
>
> A: One is acidic, and the the other is a caustic :-)
>
> Sorry, couldn't resist.

Mitch,

Hey, that's pretty good! Did you plan the "resist" pun? Yeah, I'm not sure about the rest of us, but I'm certainly a little strange. I don't know that Aspergers hits it right or not. Socially, maybe. In my case, I'm more like a whale that swims benignly under water, but every once in while I breach the surface and blow out my blow hole! My one saving grace is that try to follow Rule 62: "Don't take yourself so damn seriously!"

Best to all,

Todd Carney

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-19 by Mitch Davis

On Wed, Mar 20, 2013 at 2:59 AM, Todd Carney / K7TFC <k7tfc@...> wrote:
> --- In Homebrew_PCBs@yahoogroups.com, Mitch Davis <mjd@...> wrote:
>>
>> Q: What's the difference between HF and Todd F. Carney?
>>
>> A: One is acidic, and the the other is a caustic :-)
>>
>> Sorry, couldn't resist.
>
> Hey, that's pretty good! Did you plan the "resist" pun?

No, I'm not that smart :-)

> every once in while I breach the surface and blow out my blow hole!

I'm not saying anything :-)

Some people do go for quality rather than quantity. Those people,
when they say something, I listen.

And thanks for taking this with good grace.

Mitch.

Re: etching the OD of a cylinder to create a graduated dial

2013-03-19 by Andrew

Rick,

When you say "a new method," do you mean new compared to the mirror-image-on-clear-plastic that you described earlier, or are you also including new as compared to the standard machinist route using a dividing head and number stamps?

I understand that you want to try an etching method, and if you succeed I will be interested in seeing your results. My suspicion is that it will not be as clear and crisp as the dividing head look ... but of course, I may be proved wrong.

A year or so ago, a participant on the Practical Machinist forum described his rebuild of a large bandsaw (over a span of many, many posts); IIRC, one segment detailed his re-creation of some machine plates using an etching process. These were flat, however, rather than cylindrical -- a much easier proposition. Still, might be worth looking at for ideas, if you haven't already seen it.

--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:
>
> Mitch,
>
> There are many ways to engrave and/or stamp dials. I'm looking for a way to do it with etching. My goal is not the dial but rather a new method.
>
> Rick
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Mitch Davis
> Sent: Tuesday, March 19, 2013 7:50 AM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial
>
> On Tue, Mar 19, 2013 at 10:51 AM, Rick Sparber <rgsparber@...> wrote:
> >
> > How would the stepper fit into my plan to etch the dial?
>
> Maybe the stepper could rotate the cylinder and a tool could carve the graduations. Etch, carve, as long as you end up with the graduations
> :-)
>
> Mitch.
>

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-19 by Rick Sparber

Andrew,

By "new method" I mean chemical etching. My hobby is "inventing". I do have
a lathe, mill, and shaper so could make a dial if I wanted but that is with
standard methods. When I etch a circuit board, the features are very shape
and detailed. So why would I not get crisp features on a dial?

I can transfer toner to metal by using kitchen parchment paper and crazy
glue. Works OK. But true etching would be far more interesting right now.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Andrew
Sent: Tuesday, March 19, 2013 1:53 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

Rick,

When you say "a new method," do you mean new compared to the
mirror-image-on-clear-plastic that you described earlier, or are you also
including new as compared to the standard machinist route using a dividing
head and number stamps?

I understand that you want to try an etching method, and if you succeed I
will be interested in seeing your results. My suspicion is that it will not
be as clear and crisp as the dividing head look ... but of course, I may be
proved wrong.

A year or so ago, a participant on the Practical Machinist forum described
his rebuild of a large bandsaw (over a span of many, many posts); IIRC, one
segment detailed his re-creation of some machine plates using an etching
process. These were flat, however, rather than cylindrical -- a much easier
proposition. Still, might be worth looking at for ideas, if you haven't
already seen it.

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-19 by Andrew Volk

Rick -



If the dial has to be continuous and accurate around the entire cylinder,
then the etch method has some inherent limitation of getting the "wrap" just
right. Is your transparency method good in this case? The other problem I
have encountered when I tried (note tried, but not succeeded) to etch into
solid backgrounds with TT is that the depth needed seemed to be more than
the method would withstand. Copper clad is thin stuff and the substrate is
inherently a good etch stop and visual contrast for the etch. I could use
some help myself with fine line solid metal (aluminum preferably, or brass)
using TT.



Andy



From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Rick Sparber
Sent: Tuesday, March 19, 2013 3:34 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial





Andrew,

By "new method" I mean chemical etching. My hobby is "inventing". I do have
a lathe, mill, and shaper so could make a dial if I wanted but that is with
standard methods. When I etch a circuit board, the features are very shape
and detailed. So why would I not get crisp features on a dial?

I can transfer toner to metal by using kitchen parchment paper and crazy
glue. Works OK. But true etching would be far more interesting right now.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs%40yahoogroups.com>
[mailto:Homebrew_PCBs@yahoogroups.com
<mailto:Homebrew_PCBs%40yahoogroups.com> ]
On Behalf Of Andrew
Sent: Tuesday, March 19, 2013 1:53 PM
To: Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs%40yahoogroups.com>
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

Rick,

When you say "a new method," do you mean new compared to the
mirror-image-on-clear-plastic that you described earlier, or are you also
including new as compared to the standard machinist route using a dividing
head and number stamps?

I understand that you want to try an etching method, and if you succeed I
will be interested in seeing your results. My suspicion is that it will not
be as clear and crisp as the dividing head look ... but of course, I may be
proved wrong.

A year or so ago, a participant on the Practical Machinist forum described
his rebuild of a large bandsaw (over a span of many, many posts); IIRC, one
segment detailed his re-creation of some machine plates using an etching
process. These were flat, however, rather than cylindrical -- a much easier
proposition. Still, might be worth looking at for ideas, if you haven't
already seen it.





[Non-text portions of this message have been removed]

Re: etching the OD of a cylinder to create a graduated dial

2013-03-20 by cunningfellow

> Andrew V wrote:
> <SNIP>
> The other problem I have encountered when I
> tried (note tried, but not succeeded) to etch
> into solid backgrounds with TT is that the
> depth needed seemed to be more than the
> method would withstand.
> <SNIP>

These where done with TT (pulsar+TRF)

http://www.instructables.com/file/F6S25EMH742SAKC#step22

That is 0.35mm depth of etch on those fingers.

I am sure a dial does no need to etch that deep.

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-20 by Rick Sparber

Andy,

The dial has to be continuous in most cases. I did have to play around a bit
to get it to not overlap but finally did figure it out.

By TT I assume you mean toner transfer. I never could get it to work either
with etching. The toner breaks down too quickly. I was gluing the toner down
with the crazy glue. Can't etch through it.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Andrew Volk
Sent: Tuesday, March 19, 2013 4:22 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

Rick -



If the dial has to be continuous and accurate around the entire cylinder,
then the etch method has some inherent limitation of getting the "wrap" just
right. Is your transparency method good in this case? The other problem I
have encountered when I tried (note tried, but not succeeded) to etch into
solid backgrounds with TT is that the depth needed seemed to be more than
the method would withstand. Copper clad is thin stuff and the substrate is
inherently a good etch stop and visual contrast for the etch. I could use
some help myself with fine line solid metal (aluminum preferably, or brass)
using TT.



Andy



From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Rick Sparber
Sent: Tuesday, March 19, 2013 3:34 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial





Andrew,

By "new method" I mean chemical etching. My hobby is "inventing". I do have
a lathe, mill, and shaper so could make a dial if I wanted but that is with
standard methods. When I etch a circuit board, the features are very shape
and detailed. So why would I not get crisp features on a dial?

I can transfer toner to metal by using kitchen parchment paper and crazy
glue. Works OK. But true etching would be far more interesting right now.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs%40yahoogroups.com>
[mailto:Homebrew_PCBs@yahoogroups.com
<mailto:Homebrew_PCBs%40yahoogroups.com> ] On Behalf Of Andrew
Sent: Tuesday, March 19, 2013 1:53 PM
To: Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs%40yahoogroups.com>
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

Rick,

When you say "a new method," do you mean new compared to the
mirror-image-on-clear-plastic that you described earlier, or are you also
including new as compared to the standard machinist route using a dividing
head and number stamps?

I understand that you want to try an etching method, and if you succeed I
will be interested in seeing your results. My suspicion is that it will not
be as clear and crisp as the dividing head look ... but of course, I may be
proved wrong.

A year or so ago, a participant on the Practical Machinist forum described
his rebuild of a large bandsaw (over a span of many, many posts); IIRC, one
segment detailed his re-creation of some machine plates using an etching
process. These were flat, however, rather than cylindrical -- a much easier
proposition. Still, might be worth looking at for ideas, if you haven't
already seen it.





[Non-text portions of this message have been removed]



------------------------------------

Be sure to visit the group home and check for new Links, Files, and Photos:
http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links

Re: etching the OD of a cylinder to create a graduated dial

2013-03-20 by Andrew

As I said, I understand that you want to try the etching route; I was just curious if you had also explored the other options.

Some of the later responses have detailed some reasons why the results may not be crisp -- the problem of getting a good pattern transferred onto a round surface; the possible problem of undercutting if you go to much depth; the possible problem of getting an even etch at all points. The latter two points may be especially acute when trying to produce consistent, fine lines appropriate for machinist levels of precision -- particularly if you leave the lines "raised" against an etched background.

None of these are intended as arguments against trying it. On the contrary, I hope you do try it, and I hope that this discussion helps you as you anticipate and work through possible challenges. (The latter is part of the fun in inventing, right?) The key questions I will be interested in seeing answered are the following: 1) Does the method produce results as good as (or better than, or worse than) the standard approach? 2) Can acceptable results be produced as easily as (or more easily than, or less easily than) the standard approach?

I look forward to seeing your results.

--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:
>
> Andrew,
>
> By "new method" I mean chemical etching. My hobby is "inventing". I do have
> a lathe, mill, and shaper so could make a dial if I wanted but that is with
> standard methods. When I etch a circuit board, the features are very shape
> and detailed. So why would I not get crisp features on a dial?
>
> I can transfer toner to metal by using kitchen parchment paper and crazy
> glue. Works OK. But true etching would be far more interesting right now.
>
> Rick
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Andrew
> Sent: Tuesday, March 19, 2013 1:53 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
> graduated dial
>
> Rick,
>
> When you say "a new method," do you mean new compared to the
> mirror-image-on-clear-plastic that you described earlier, or are you also
> including new as compared to the standard machinist route using a dividing
> head and number stamps?
>
> I understand that you want to try an etching method, and if you succeed I
> will be interested in seeing your results. My suspicion is that it will not
> be as clear and crisp as the dividing head look ... but of course, I may be
> proved wrong.
>
> A year or so ago, a participant on the Practical Machinist forum described
> his rebuild of a large bandsaw (over a span of many, many posts); IIRC, one
> segment detailed his re-creation of some machine plates using an etching
> process. These were flat, however, rather than cylindrical -- a much easier
> proposition. Still, might be worth looking at for ideas, if you haven't
> already seen it.
>

Re: etching the OD of a cylinder to create a graduated dial

2013-03-20 by Andrew

This picture is certainly helpful, but does raise some questions. I notice some waviness in the outlines, but I am guessing that may have been intentional? For a machine tool dial, anything less than narrow, crisp, straight lines will reduce its usefulness. Normally when I make a dial or something similar, the width of the line I cut in the metal is in the vicinity of .001" to .002" -- just a slice made with a sharp tool. I have doubts about the feasibility of producing consistent, clearly visible lines of that width by etching around a pattern (leaving the lines embossed) as Rick is proposing to do.

Again, half the fun of inventing is proving the doubters wrong! I look forward to seeing what Rick will come up with.

--- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@...> wrote:
>
>
>
> > Andrew V wrote:
> > <SNIP>
> > The other problem I have encountered when I
> > tried (note tried, but not succeeded) to etch
> > into solid backgrounds with TT is that the
> > depth needed seemed to be more than the
> > method would withstand.
> > <SNIP>
>
> These where done with TT (pulsar+TRF)
>
> http://www.instructables.com/file/F6S25EMH742SAKC#step22
>
> That is 0.35mm depth of etch on those fingers.
>
> I am sure a dial does no need to etch that deep.
>

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-20 by Rick Sparber

Andrew,

I've been "tilting at this windmill" for a few years on and off. So far,
none of my methods have been good enough although printing to clear plastic
mirror image came close.

I am convinced that toner is not strong enough to hold back acid or electro
etch reliably. I do believe that a layer of wax will stop acid and electro
etch. The trick is how to selectively apply or remove the wax. The
alternative is to use a photo sensitive coating. What has stopped me there
is cost and the fact that it is already available so nothing new.

My guess is that with wax, I could etch deep enough to make it look good.
Not so sure it would work if the wax was only on the number and lines. This
is the raised approach you mentioned. That would be rather weak. But if it
did work, I think it would look better.

As to your excellent questions:

1. if a given method does not produce results as good as mechanical
engraving and stamping, then I would move on to the next method.
2. the standard approach of scribing and stamping is very hard for me to do
consistently. I might get reasonable scribe lines 99% of the time which
means 1% are screwed up and will jump out at me. With metal stamps, the
success rate is more like 50%. With a good fixture, I should be able to
improve this to maybe 75%. Still, plenty of room for improvement.

My goal is to get consistent results with relatively low skill and certainly
low cost. It would be nice if a wax coating was part of the answer since it
meets these criteria.

As my friend Dan tells me, "I'm like a dog with a bone." When I find an
interesting problem to solve, I keep at it until it is solved.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Andrew
Sent: Wednesday, March 20, 2013 8:59 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

As I said, I understand that you want to try the etching route; I was just
curious if you had also explored the other options.

Some of the later responses have detailed some reasons why the results may
not be crisp -- the problem of getting a good pattern transferred onto a
round surface; the possible problem of undercutting if you go to much depth;
the possible problem of getting an even etch at all points. The latter two
points may be especially acute when trying to produce consistent, fine lines
appropriate for machinist levels of precision -- particularly if you leave
the lines "raised" against an etched background.

None of these are intended as arguments against trying it. On the contrary,
I hope you do try it, and I hope that this discussion helps you as you
anticipate and work through possible challenges. (The latter is part of the
fun in inventing, right?) The key questions I will be interested in seeing
answered are the following: 1) Does the method produce results as good as
(or better than, or worse than) the standard approach? 2) Can acceptable
results be produced as easily as (or more easily than, or less easily than)
the standard approach?

I look forward to seeing your results.

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-20 by Rick Sparber

My gold standard are the dials on my Craftsman/Atlas lathe. My guess is
those scribed lines are around 0.002" wide and the numbers are all perfect.
It was build around 1964 so probably done with a machine. Not much CNC back
then.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Andrew
Sent: Wednesday, March 20, 2013 9:11 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

This picture is certainly helpful, but does raise some questions. I notice
some waviness in the outlines, but I am guessing that may have been
intentional? For a machine tool dial, anything less than narrow, crisp,
straight lines will reduce its usefulness. Normally when I make a dial or
something similar, the width of the line I cut in the metal is in the
vicinity of .001" to .002" -- just a slice made with a sharp tool. I have
doubts about the feasibility of producing consistent, clearly visible lines
of that width by etching around a pattern (leaving the lines embossed) as
Rick is proposing to do.

Again, half the fun of inventing is proving the doubters wrong! I look
forward to seeing what Rick will come up with.

Re: etching the OD of a cylinder to create a graduated dial

2013-03-20 by Andrew

I went back and looked at some dials, and revised my estimate -- I think a line of .005" to even as much as .010" would be acceptable, unless the dial is very small. I have made a sample PCB using.005" lines with TT, but it was pretty iffy.

If I understood correctly, you said that a photo resist method of etching dials has been done? It would seem like this would be the best approach for etching. Perhaps a spray-on photo resist would work well?

I've not worked enough with wax to have a feel for how well that could work, either in terms of transfer or in terms of resist.

Again, I look forward to what you come up with ...

--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:
>
> My gold standard are the dials on my Craftsman/Atlas lathe. My guess is
> those scribed lines are around 0.002" wide and the numbers are all perfect.
> It was build around 1964 so probably done with a machine. Not much CNC back
> then.
>
> Rick
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Andrew
> Sent: Wednesday, March 20, 2013 9:11 AM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
> graduated dial
>
> This picture is certainly helpful, but does raise some questions. I notice
> some waviness in the outlines, but I am guessing that may have been
> intentional? For a machine tool dial, anything less than narrow, crisp,
> straight lines will reduce its usefulness. Normally when I make a dial or
> something similar, the width of the line I cut in the metal is in the
> vicinity of .001" to .002" -- just a slice made with a sharp tool. I have
> doubts about the feasibility of producing consistent, clearly visible lines
> of that width by etching around a pattern (leaving the lines embossed) as
> Rick is proposing to do.
>
> Again, half the fun of inventing is proving the doubters wrong! I look
> forward to seeing what Rick will come up with.
>

Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-20 by cary heestand

Hi Andrew, here is a link to a pretty good PDF for "art" type etching. It gives both etchant formulas and resist formulas. Knife makers and jewelry makers use this and there are tons of other links in Google. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=0CFYQFjAE&url=http%3A%2F%2Fwww.ganoksin.com%2Fftp%2Fedinburg-etch.pdf&ei=MvlJUZS-Cob9ygH1-YBw&usg=AFQjCNGgUEVmymd6RCPzoZAZLEHVGbUS0Q&bvm=bv.44011176,d.aWc

cary

PS, hows the EDM working?

--- On Wed, 3/20/13, Andrew <a_wake@...> wrote:

From: Andrew <a_wake@...>
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial
To: Homebrew_PCBs@yahoogroups.com
Date: Wednesday, March 20, 2013, 12:56 PM


























I went back and looked at some dials, and revised my estimate -- I think a line of .005" to even as much as .010" would be acceptable, unless the dial is very small. I have made a sample PCB using.005" lines with TT, but it was pretty iffy.



If I understood correctly, you said that a photo resist method of etching dials has been done? It would seem like this would be the best approach for etching. Perhaps a spray-on photo resist would work well?



I've not worked enough with wax to have a feel for how well that could work, either in terms of transfer or in terms of resist.



Again, I look forward to what you come up with ...



--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:

>

> My gold standard are the dials on my Craftsman/Atlas lathe. My guess is

> those scribed lines are around 0.002" wide and the numbers are all perfect.

> It was build around 1964 so probably done with a machine. Not much CNC back

> then.

>

> Rick

>

> -----Original Message-----

> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]

> On Behalf Of Andrew

> Sent: Wednesday, March 20, 2013 9:11 AM

> To: Homebrew_PCBs@yahoogroups.com

> Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a

> graduated dial

>

> This picture is certainly helpful, but does raise some questions. I notice

> some waviness in the outlines, but I am guessing that may have been

> intentional? For a machine tool dial, anything less than narrow, crisp,

> straight lines will reduce its usefulness. Normally when I make a dial or

> something similar, the width of the line I cut in the metal is in the

> vicinity of .001" to .002" -- just a slice made with a sharp tool. I have

> doubts about the feasibility of producing consistent, clearly visible lines

> of that width by etching around a pattern (leaving the lines embossed) as

> Rick is proposing to do.

>

> Again, half the fun of inventing is proving the doubters wrong! I look

> forward to seeing what Rick will come up with.

>



























[Non-text portions of this message have been removed]

Re: etching the OD of a cylinder to create a graduated dial

2013-03-21 by cunningfellow

> Andrew W wrote:
>
> This picture is certainly helpful, but
> does raise some questions. I notice some
> waviness in the outlines, but I am guessing
> that may have been intentional?
> <SNIP>

The original robot picture did not have
straight lines. However when etching down
0.35mm you are always going to get undercut
and the undercut on toner transfer is variable.

For a dial you would not need anything near
0.35mm (0.014") depth.

I don't get consistent result with TT and
under 10thou lines and if I am going lower
than that I use photographic techniques.

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-21 by Boman33

If absolute best accuracy is wanted, coat the part with photoresist and
mount it on an accurate turntable. Set up an optical projector projecting
just one narrow line. Lock everything down and in a darkroom expose the
first line, change the turntable to the next line, expose and so on.



When done, the calibration accuracy is only limited by the turntable
accuracy, the centering of the part on the turntable and the roundness of
the part. The optical system never moved so it should be stable as long as
there are not any temperature gradients.



A second pass can be run projecting the numbers a required.



Bertho



[Non-text portions of this message have been removed]

Re: calcium carbonate, HF acid...

2013-03-21 by AlienRelics

-You- inserted sarcasm into my question. I had a pretty good idea that HF meant hydrofluoric acid. I was asking partly for those on the list who don't know what it is (and it is not guaranteed that the first Google result is the correct hit), and partly to remind people to spell out what they mean now and then.

I wasn't aware that "HF" was a "big fancy word".

I notice you said nothing about the part about hijacking the thread.

As for me being a troll, I'm the listowner, Einstein. Something you could have looked up easily enough. Dunning-Kruger?

Steve Greenfield AE7HD
your occasionally fed-up moderator

--- In Homebrew_PCBs@yahoogroups.com, "Todd F. Carney / K7TFC" <k7tfc@...> wrote:
>
> Google "hf acid." The very first item on the page--big as life--will answer
> your question and tell you all about it. Oh, I'm not a chemist, either. I'm
> just a guy of normal intelligence who knows how to use a web browser. I
> also know better than to broadcast my stupidity for intelligent people to
> see.
>
> Sorry about this peevish (look that up, too) response, but this kind of
> "Okay, *Einstein*, what does that big fancy word mean, anyway?" attitude
> really bugs me. I actually think it's mostly trolls who do this kind of
> thing, so it's just one more thing to ignore.
>
> I must be in a "mood." I guess I better go solder something together.
>
> 73,
>
> Todd
> ------------------------------------------------------------------------------------
> K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
> ------------------------------------------------------------------------------------
> QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
>
>
> On Mon, Mar 18, 2013 at 2:39 PM, AlienRelics <alienrelics@...> wrote:
>
> > **
> >
> >
> > OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat hijacks
> > keepitsimplestupid's hijacked thread. Interesting.
> >
> > For those of us who are not chemists, what is HF acid?
> >
> > Steve Greenfield AE7HD
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "smilingcat90254" <smilingcat@>
> > wrote:
> > >
> > > Calcium carbonate for that matter most carbonate will react with even
> > trace amount of hydrochloric acid remaining in your etchant. And yes it
> > will foam because CO2 is being released in the reaction. So if your
> > solution keeps foaming keep adding the carbonate. It will neutralize the
> > acid for safe disposal.
> > >
> > > Reaction of Copper chloride and Calcium carbonate probably will be much
> > slower than Copper chloride and sodium carbonate. But it should work. not
> > 100% plus sure.
> > >
> > > **** HF acid ****
> > > I was in semiconductor manufacturing business so I'm quite aware of HF
> > acid. Very dangerous stuff. No you can not store in a glass. It will etch
> > glass. No you can not store in stainless steel container!!
> > >
> > > HF chemical burn is severe even at low concentration. It will penetrate
> > bare skin and the flourine ion will interact with the calcium in your bone.
> > HF will dissolve your bone under all the tissue.
> > >
> > > I didn't think you can buy it unless you can show you are a business or
> > a researcher of some sort.
> > >
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>

Re: [Homebrew_PCBs] Re: calcium carbonate, HF acid...

2013-03-21 by Todd F. Carney / K7TFC

I think I've already admitted my stupidity here, and that I regret my
off-the-cuff response. I guess all that's left is to apologize to you
personally, and to thank you for your work as moderator.

73,

Todd
------------------------------------------------------------------------------------
K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
------------------------------------------------------------------------------------
QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design


On Wed, Mar 20, 2013 at 8:19 PM, AlienRelics <alienrelics@...> wrote:

> **
>
>
> -You- inserted sarcasm into my question. I had a pretty good idea that HF
> meant hydrofluoric acid. I was asking partly for those on the list who
> don't know what it is (and it is not guaranteed that the first Google
> result is the correct hit), and partly to remind people to spell out what
> they mean now and then.
>
> I wasn't aware that "HF" was a "big fancy word".
>
> I notice you said nothing about the part about hijacking the thread.
>
> As for me being a troll, I'm the listowner, Einstein. Something you could
> have looked up easily enough. Dunning-Kruger?
>
> Steve Greenfield AE7HD
> your occasionally fed-up moderator
>
> --- In Homebrew_PCBs@yahoogroups.com, "Todd F. Carney / K7TFC" <k7tfc@...>
> wrote:
> >
> > Google "hf acid." The very first item on the page--big as life--will
> answer
> > your question and tell you all about it. Oh, I'm not a chemist, either.
> I'm
> > just a guy of normal intelligence who knows how to use a web browser. I
>
> > also know better than to broadcast my stupidity for intelligent people to
> > see.
> >
> > Sorry about this peevish (look that up, too) response, but this kind of
> > "Okay, *Einstein*, what does that big fancy word mean, anyway?" attitude
> > really bugs me. I actually think it's mostly trolls who do this kind of
> > thing, so it's just one more thing to ignore.
> >
> > I must be in a "mood." I guess I better go solder something together.
> >
> > 73,
> >
> > Todd
> > ----------------------------------------------------------
> > K7TFC / Medford, Oregon, USA / CN82ni / UTC-8
> > ----------------------------------------------------------
> > QRP (CW & SSB) / EmComm / SOTA / Homebrew / Design
> >
> >
> > On Mon, Mar 18, 2013 at 2:39 PM, AlienRelics <alienrelics@...> wrote:
> >
> > > **
> > >
> > >
> > > OK, so keepitsimplestupid hijack's Ricks thread, and smilingcat hijacks
> > > keepitsimplestupid's hijacked thread. Interesting.
> > >
> > > For those of us who are not chemists, what is HF acid?
> > >
> > > Steve Greenfield AE7HD
> > >
> > > --- In Homebrew_PCBs@yahoogroups.com, "smilingcat90254" <smilingcat@>
> > > wrote:
> > > >
> > > > Calcium carbonate for that matter most carbonate will react with even
> > > trace amount of hydrochloric acid remaining in your etchant. And yes it
> > > will foam because CO2 is being released in the reaction. So if your
> > > solution keeps foaming keep adding the carbonate. It will neutralize
> the
> > > acid for safe disposal.
> > > >
> > > > Reaction of Copper chloride and Calcium carbonate probably will be
> much
> > > slower than Copper chloride and sodium carbonate. But it should work.
> not
> > > 100% plus sure.
> > > >
> > > > **** HF acid ****
> > > > I was in semiconductor manufacturing business so I'm quite aware of
> HF
> > > acid. Very dangerous stuff. No you can not store in a glass. It will
> etch
> > > glass. No you can not store in stainless steel container!!
> > > >
> > > > HF chemical burn is severe even at low concentration. It will
> penetrate
> > > bare skin and the flourine ion will interact with the calcium in your
> bone.
> > > HF will dissolve your bone under all the tissue.
> > > >
> > > > I didn't think you can buy it unless you can show you are a business
> or
> > > a researcher of some sort.
> > > >
> > >
> > >
> > >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>


[Non-text portions of this message have been removed]

Re: calcium carbonate, HF acid...

2013-03-21 by AlienRelics

Yes, thanks, I know what the heck hydrofluoric acid is, I've known since I was, well, can't remember how young I was. And known that it can even eat through glass. And it is quite nasty and dangerous.

Read my other message for why I asked the question.

Sheesh.

Steve Greenfield AE7HD
your normally friendly neighborhood moderator

--- In Homebrew_PCBs@yahoogroups.com, Roland Harriston <rolohar@...> wrote:
>
> I agree:
>
> But, yet, I wonder about people who will not or cannot use Google (at
> this stage of the game)
> to independently look something up. and not broadcast to the entire
> world-wide web that they don't know what something is.
> HF acid is not that exotic.
>
> Pardon my snark, but if you are messing around with this kind of stuff,
> "Google-ing"
> should be old hat.
>
> Roland F. Harriston, P.D.
> **********************
>

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-21 by Rick Sparber

Sorry, but I was not part of your "we"....

But I am now :-)

Thanks, I'll study up on it.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of cunningfellow
Sent: Wednesday, March 20, 2013 5:12 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

> Rick S wrote:
> <SNIP>
> The trick is how to selectively apply or remove the wax.
> <SNIP>

Well we know inkjets work for molten wax.

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-21 by Rick Sparber

What do you suggest for user applied photoresist? PnP?

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Boman33
Sent: Wednesday, March 20, 2013 6:41 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

If absolute best accuracy is wanted, coat the part with photoresist and
mount it on an accurate turntable. Set up an optical projector projecting
just one narrow line. Lock everything down and in a darkroom expose the
first line, change the turntable to the next line, expose and so on.



When done, the calibration accuracy is only limited by the turntable
accuracy, the centering of the part on the turntable and the roundness of
the part. The optical system never moved so it should be stable as long as
there are not any temperature gradients.



A second pass can be run projecting the numbers a required.



Bertho



[Non-text portions of this message have been removed]



------------------------------------

Be sure to visit the group home and check for new Links, Files, and Photos:
http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-21 by Rick Sparber

Andrew,

I know that photo etching has been done on flat plates so assumed it could
be made to work on a cylinder. I would wrap the artwork around the cylinder
and rotate it at a constant rate under the UV light. The missing link here
for me is an easy to apply photo resist. I've always used pre-treated
circuit board material and had good results.

One option I may pursue would be to coat the cylinder with wax and then use
engraving techniques to scribe through only the wax. In this way, mistakes
can be fixed by reflowing the wax. Not sure how to do the numbers. This
method probably would work but is too much effort for me. If a spray-on
photo resist could be made to work, that would be the key.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Andrew
Sent: Wednesday, March 20, 2013 9:56 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

I went back and looked at some dials, and revised my estimate -- I think a
line of .005" to even as much as .010" would be acceptable, unless the dial
is very small. I have made a sample PCB using.005" lines with TT, but it was
pretty iffy.

If I understood correctly, you said that a photo resist method of etching
dials has been done? It would seem like this would be the best approach for
etching. Perhaps a spray-on photo resist would work well?

I've not worked enough with wax to have a feel for how well that could work,
either in terms of transfer or in terms of resist.

Again, I look forward to what you come up with ...

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-21 by Rick Sparber

Cary,

I found this information very good for etchant formulas but all of the resists are non-photo. Got any homemade photo resist formulas?

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of cary heestand
Sent: Wednesday, March 20, 2013 11:12 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

Hi Andrew, here is a link to a pretty good PDF for "art" type etching. It gives both etchant formulas and resist formulas. Knife makers and jewelry makers use this and there are tons of other links in Google. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=0CFYQFjAE&url=http%3A%2F%2Fwww.ganoksin.com%2Fftp%2Fedinburg-etch.pdf&ei=MvlJUZS-Cob9ygH1-YBw&usg=AFQjCNGgUEVmymd6RCPzoZAZLEHVGbUS0Q&bvm=bv.44011176,d.aWc

cary

Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-21 by Harvey White

On Thu, 21 Mar 2013 11:18:29 -0700, you wrote:

>Andrew,
>
>I know that photo etching has been done on flat plates so assumed it could
>be made to work on a cylinder. I would wrap the artwork around the cylinder
>and rotate it at a constant rate under the UV light. The missing link here
>for me is an easy to apply photo resist. I've always used pre-treated
>circuit board material and had good results.
>
>One option I may pursue would be to coat the cylinder with wax and then use
>engraving techniques to scribe through only the wax. In this way, mistakes
>can be fixed by reflowing the wax. Not sure how to do the numbers. This
>method probably would work but is too much effort for me. If a spray-on
>photo resist could be made to work, that would be the key.

Try a pantograph and larger patterns to engrave the numbers. Another
option would be Laser engraving. You need to rotate the cylinder and
move perpendicularly to the axis. Same thing for normal engraving.

Might be worth the effort.

Harvey

>
>Rick
>
>-----Original Message-----
>From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
>On Behalf Of Andrew
>Sent: Wednesday, March 20, 2013 9:56 AM
>To: Homebrew_PCBs@yahoogroups.com
>Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
>graduated dial
>
>I went back and looked at some dials, and revised my estimate -- I think a
>line of .005" to even as much as .010" would be acceptable, unless the dial
>is very small. I have made a sample PCB using.005" lines with TT, but it was
>pretty iffy.
>
>If I understood correctly, you said that a photo resist method of etching
>dials has been done? It would seem like this would be the best approach for
>etching. Perhaps a spray-on photo resist would work well?
>
>I've not worked enough with wax to have a feel for how well that could work,
>either in terms of transfer or in terms of resist.
>
>Again, I look forward to what you come up with ...

Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-22 by Missouri Guy

>Got any homemade photo resist formulas?

Now THAT would be great!!!! Something that can be sprayed
on with a "household" sprayer. AND, some kinda stuff that
would have a good shelf life.

Charlie

On Thu, 21 Mar 2013 11:20:06 -0700 "Rick Sparber" <rgsparber@...>
writes:

Cary,

I found this information very good for etchant formulas but all of the
resists are non-photo. Got any homemade photo resist formulas?

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com
[mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of cary heestand
Sent: Wednesday, March 20, 2013 11:12 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

Hi Andrew, here is a link to a pretty good PDF for "art" type etching. It
gives both etchant formulas and resist formulas. Knife makers and jewelry
makers use this and there are tons of other links in Google.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=0CFYQF
jAE&url=http%3A%2F%2Fwww.ganoksin.com%2Fftp%2Fedinburg-etch.pdf&ei=MvlJUZ
S-Cob9ygH1-YBw&usg=AFQjCNGgUEVmymd6RCPzoZAZLEHVGbUS0Q&bvm=bv.44011176,d.a
Wc

cary




[Non-text portions of this message have been removed]

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-22 by Rick Sparber

Charlie,

I would prefer something that I can dip the part into and have it come out with a uniform thickness. But since I have not seen anything like this as a homebrew, I suspect it isn't that simple. Any chemists out there to explain why?

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Missouri Guy
Sent: Thursday, March 21, 2013 5:43 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

>Got any homemade photo resist formulas?

Now THAT would be great!!!! Something that can be sprayed on with a "household" sprayer. AND, some kinda stuff that would have a good shelf life.

Charlie

On Thu, 21 Mar 2013 11:20:06 -0700 "Rick Sparber" <rgsparber@...>
writes:

Cary,

I found this information very good for etchant formulas but all of the resists are non-photo. Got any homemade photo resist formulas?

Rick

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-22 by Rick Sparber

Harvey,

Pantographs and lasers are all existing technologies. My hobby is to invent
new things, especially things that are simple. So if I could apply some
homemade mixture to the cylinder, do a contact print, and then etch, I would
be happy.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Harvey White
Sent: Thursday, March 21, 2013 1:29 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

On Thu, 21 Mar 2013 11:18:29 -0700, you wrote:

>Andrew,
>
>I know that photo etching has been done on flat plates so assumed it
>could be made to work on a cylinder. I would wrap the artwork around
>the cylinder and rotate it at a constant rate under the UV light. The
>missing link here for me is an easy to apply photo resist. I've always
>used pre-treated circuit board material and had good results.
>
>One option I may pursue would be to coat the cylinder with wax and then
>use engraving techniques to scribe through only the wax. In this way,
>mistakes can be fixed by reflowing the wax. Not sure how to do the
>numbers. This method probably would work but is too much effort for me.
>If a spray-on photo resist could be made to work, that would be the key.

Try a pantograph and larger patterns to engrave the numbers. Another option
would be Laser engraving. You need to rotate the cylinder and move
perpendicularly to the axis. Same thing for normal engraving.

Might be worth the effort.

Harvey

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-22 by Rick Sparber

Jim,

Looks like a fun machine but a bit too complex compared to contact printing
and chemical etching.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Jim
Sent: Friday, March 22, 2013 7:37 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial



--- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@...>
wrote:
>
> > Rick S wrote:
> > <SNIP>
> > The trick is how to selectively apply or remove the wax.
> > <SNIP>
>
> Well we know inkjets work for molten wax.
>

Maybe an Eggbot with a scriber if the cylinder isn't too big?
http://egg-bot.com/

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-22 by Malcolm Parker-Lisberg

Rick

You could use one of the etch resist pens on it though.

Malcolm

I don't suffer from insanity I enjoy it!

Mene, mene, tekel, upharsin

The writing is on the wall.

--- On Fri, 3/22/13, Rick Sparber <rgsparber@...> wrote:

From: Rick Sparber <rgsparber@...>
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial
To: Homebrew_PCBs@yahoogroups.com
Date: Friday, March 22, 2013, 2:46 PM


























Jim,



Looks like a fun machine but a bit too complex compared to contact printing

and chemical etching.



Rick



-----Original Message-----

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]

On Behalf Of Jim

Sent: Friday, March 22, 2013 7:37 AM

To: Homebrew_PCBs@yahoogroups.com

Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a

graduated dial



--- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@...>

wrote:

>

> > Rick S wrote:

> > <SNIP>

> > The trick is how to selectively apply or remove the wax.

> > <SNIP>

>

> Well we know inkjets work for molten wax.

>



Maybe an Eggbot with a scriber if the cylinder isn't too big?

http://egg-bot.com/



























[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-23 by Donald H Locker

Might I suggest using a commercial product first (to verify one part of the process using known commercial materials) then move to making your own photoresist? <http://www.vetco.net/catalog/product_info.php?products_id=937> is one example; I'm sure Digikey carries something like it. Many years ago, silkscreen photoresists were made with Elmer's Glue and some additive that I can't for the life of me remember. That would be what I would search for. (The sensitiser was a chromate or bi-chromate, I think.)

HTH,
Donald.
--
*Plain Text* email -- it's an accessibility issue
() no proprietary attachments; no html mail
/\ ascii ribbon campaign - <www.asciiribbon.org>

----- Original Message -----
> From: "Rick Sparber" <rgsparber@...>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Friday, March 22, 2013 8:25:15 AM
> Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial
> Harvey,
>
> Pantographs and lasers are all existing technologies. My hobby is to invent
> new things, especially things that are simple. So if I could apply some
> homemade mixture to the cylinder, do a contact print, and then etch, I would
> be happy.
>
> Rick
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Harvey White
> Sent: Thursday, March 21, 2013 1:29 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to
> create a
> graduated dial
>
> On Thu, 21 Mar 2013 11:18:29 -0700, you wrote:
>
> >Andrew,
> >
> >I know that photo etching has been done on flat plates so assumed it
> >could be made to work on a cylinder. I would wrap the artwork around
> >the cylinder and rotate it at a constant rate under the UV light. The
> >missing link here for me is an easy to apply photo resist. I've
> >always
> >used pre-treated circuit board material and had good results.
> >
> >One option I may pursue would be to coat the cylinder with wax and
> >then
> >use engraving techniques to scribe through only the wax. In this way,
> >mistakes can be fixed by reflowing the wax. Not sure how to do the
> >numbers. This method probably would work but is too much effort for
> >me.
> >If a spray-on photo resist could be made to work, that would be the
> >key.
>
> Try a pantograph and larger patterns to engrave the numbers. Another
> option
> would be Laser engraving. You need to rotate the cylinder and move
> perpendicularly to the axis. Same thing for normal engraving.
>
> Might be worth the effort.
>
> Harvey
>

Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-23 by Donald H Locker

Diazo! <http://www.amazon.com/Speedball-Diazo-Photo-Emulsion/dp/B0011YTZ9G/ref=sr_1_2?ie=UTF8&qid=1364002783&sr=8-2&keywords=diazo+emulsion>

Donald.
--
*Plain Text* email -- it's an accessibility issue
() no proprietary attachments; no html mail
/\ ascii ribbon campaign - <www.asciiribbon.org>

----- Original Message -----
> From: "Rick Sparber" <rgsparber@...>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Friday, March 22, 2013 8:25:15 AM
> Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial
> Harvey,
>
> Pantographs and lasers are all existing technologies. My hobby is to
> invent
> new things, especially things that are simple. So if I could apply
> some
> homemade mixture to the cylinder, do a contact print, and then etch, I
> would
> be happy.
>
> Rick
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Harvey White
> Sent: Thursday, March 21, 2013 1:29 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to
> create a
> graduated dial
>
> On Thu, 21 Mar 2013 11:18:29 -0700, you wrote:
>
> >Andrew,
> >
> >I know that photo etching has been done on flat plates so assumed it
> >could be made to work on a cylinder. I would wrap the artwork around
> >the cylinder and rotate it at a constant rate under the UV light. The
> >missing link here for me is an easy to apply photo resist. I've
> >always
> >used pre-treated circuit board material and had good results.
> >
> >One option I may pursue would be to coat the cylinder with wax and
> >then
> >use engraving techniques to scribe through only the wax. In this way,
> >mistakes can be fixed by reflowing the wax. Not sure how to do the
> >numbers. This method probably would work but is too much effort for
> >me.
> >If a spray-on photo resist could be made to work, that would be the
> >key.
>
> Try a pantograph and larger patterns to engrave the numbers. Another
> option
> would be Laser engraving. You need to rotate the cylinder and move
> perpendicularly to the axis. Same thing for normal engraving.
>
> Might be worth the effort.
>
> Harvey
>
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-23 by Rick Sparber

Donald,

Thank you so much for this lead. I just placed the order for the negative photo resist and negative developer.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Donald H Locker
Sent: Friday, March 22, 2013 6:34 PM
To: Homebrew PCBs
Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

Might I suggest using a commercial product first (to verify one part of the process using known commercial materials) then move to making your own photoresist? <http://www.vetco.net/catalog/product_info.php?products_id=937> is one example; I'm sure Digikey carries something like it. Many years ago, silkscreen photoresists were made with Elmer's Glue and some additive that I can't for the life of me remember. That would be what I would search for. (The sensitiser was a chromate or bi-chromate, I think.)

HTH,
Donald.
--
*Plain Text* email -- it's an accessibility issue
() no proprietary attachments; no html mail /\ ascii ribbon campaign - <www.asciiribbon.org>

----- Original Message -----
> From: "Rick Sparber" <rgsparber@...>
> To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
> Sent: Friday, March 22, 2013 8:25:15 AM
> Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to
> create a graduated dial Harvey,
>
> Pantographs and lasers are all existing technologies. My hobby is to
> invent new things, especially things that are simple. So if I could
> apply some homemade mixture to the cylinder, do a contact print, and
> then etch, I would be happy.
>
> Rick
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Harvey White
> Sent: Thursday, March 21, 2013 1:29 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] Re: etching the OD of a cylinder to
> create a graduated dial
>
> On Thu, 21 Mar 2013 11:18:29 -0700, you wrote:
>
> >Andrew,
> >
> >I know that photo etching has been done on flat plates so assumed it
> >could be made to work on a cylinder. I would wrap the artwork around
> >the cylinder and rotate it at a constant rate under the UV light. The
> >missing link here for me is an easy to apply photo resist. I've
> >always used pre-treated circuit board material and had good results.
> >
> >One option I may pursue would be to coat the cylinder with wax and
> >then use engraving techniques to scribe through only the wax. In this
> >way, mistakes can be fixed by reflowing the wax. Not sure how to do
> >the numbers. This method probably would work but is too much effort
> >for me.
> >If a spray-on photo resist could be made to work, that would be the
> >key.
>
> Try a pantograph and larger patterns to engrave the numbers. Another
> option would be Laser engraving. You need to rotate the cylinder and
> move perpendicularly to the axis. Same thing for normal engraving.
>
> Might be worth the effort.
>
> Harvey
>


------------------------------------

Be sure to visit the group home and check for new Links, Files, and Photos:
http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-24 by Rick Sparber

Malcolm,

I'm going to try the spray on photo resist and then a contact print. If that doesn't work, I'll be "back at the well" looking for more ideas.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Malcolm Parker-Lisberg
Sent: Friday, March 22, 2013 8:54 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

Rick

You could use one of the etch resist pens on it though.

Malcolm

I don't suffer from insanity I enjoy it!

Mene, mene, tekel, upharsin

The writing is on the wall.

--- On Fri, 3/22/13, Rick Sparber <rgsparber@...> wrote:

From: Rick Sparber <rgsparber@...>
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial
To: Homebrew_PCBs@yahoogroups.com
Date: Friday, March 22, 2013, 2:46 PM


























Jim,



Looks like a fun machine but a bit too complex compared to contact printing

and chemical etching.



Rick



-----Original Message-----

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]

On Behalf Of Jim

Sent: Friday, March 22, 2013 7:37 AM

To: Homebrew_PCBs@yahoogroups.com

Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a

graduated dial



--- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@...>

wrote:

>

> > Rick S wrote:

> > <SNIP>

> > The trick is how to selectively apply or remove the wax.

> > <SNIP>

>

> Well we know inkjets work for molten wax.

>



Maybe an Eggbot with a scriber if the cylinder isn't too big?

http://egg-bot.com/



























[Non-text portions of this message have been removed]



------------------------------------

Be sure to visit the group home and check for new Links, Files, and Photos:
http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-24 by Malcolm Parker-Lisberg

Rick

You could try transfer printing like they use to print designs on pottery mugs. Print the resist on a flat silicone pad and roll the dial against it to transfer print. You could use epoxy ink instead of resist if you did not want to etch. I used to do something similar for transferring scales onto glass flowmeter tubes.

Malcolm

I don't suffer from insanity I enjoy it!

Mene, mene, tekel, upharsin

The writing is on the wall.

--- On Sun, 3/24/13, Rick Sparber <rgsparber@...> wrote:

From: Rick Sparber <rgsparber@...>
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial
To: Homebrew_PCBs@yahoogroups.com
Date: Sunday, March 24, 2013, 1:04 AM


























Malcolm,



I'm going to try the spray on photo resist and then a contact print. If that doesn't work, I'll be "back at the well" looking for more ideas.



Rick



-----Original Message-----

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Malcolm Parker-Lisberg

Sent: Friday, March 22, 2013 8:54 AM

To: Homebrew_PCBs@yahoogroups.com

Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial



Rick



You could use one of the etch resist pens on it though.



Malcolm



I don't suffer from insanity I enjoy it!



Mene, mene, tekel, upharsin



The writing is on the wall.



--- On Fri, 3/22/13, Rick Sparber <rgsparber@...> wrote:



From: Rick Sparber <rgsparber@...>

Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

To: Homebrew_PCBs@yahoogroups.com

Date: Friday, March 22, 2013, 2:46 PM



Jim,



Looks like a fun machine but a bit too complex compared to contact printing



and chemical etching.



Rick



-----Original Message-----



From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]



On Behalf Of Jim



Sent: Friday, March 22, 2013 7:37 AM



To: Homebrew_PCBs@yahoogroups.com



Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a



graduated dial



--- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@...>



wrote:



>



> > Rick S wrote:



> > <SNIP>



> > The trick is how to selectively apply or remove the wax.



> > <SNIP>



>



> Well we know inkjets work for molten wax.



>



Maybe an Eggbot with a scriber if the cylinder isn't too big?



http://egg-bot.com/



[Non-text portions of this message have been removed]



------------------------------------



Be sure to visit the group home and check for new Links, Files, and Photos:

http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links



























[Non-text portions of this message have been removed]

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-24 by Rick Sparber

Bertho,

I was planning on driving the cylinder with a clockwork mechanism and
"roasting" it under my UV light. If that gives poor results, I will
certainly try your suggestion.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Boman33
Sent: Wednesday, March 20, 2013 6:41 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

If absolute best accuracy is wanted, coat the part with photoresist and
mount it on an accurate turntable. Set up an optical projector projecting
just one narrow line. Lock everything down and in a darkroom expose the
first line, change the turntable to the next line, expose and so on.



When done, the calibration accuracy is only limited by the turntable
accuracy, the centering of the part on the turntable and the roundness of
the part. The optical system never moved so it should be stable as long as
there are not any temperature gradients.



A second pass can be run projecting the numbers a required.



Bertho



[Non-text portions of this message have been removed]



------------------------------------

Be sure to visit the group home and check for new Links, Files, and Photos:
http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-24 by Boman33

If you do not have a rotary table it is simple to make one since there is
zero force on the subject. A 100 tooth gear will give you accurate
indexing.

No art work is needed for the critical lines, either optical projection or a
laser line source.

Bertho



From: Rick Sparber Sent: Saturday, March 23, 2013 22:12
Bertho,
I was planning on driving the cylinder with a clockwork mechanism and
"roasting" it under my UV light. If that gives poor results, I will
certainly try your suggestion.

Rick

-----Original Message-----
From: Boman33 Sent: Wednesday, March 20, 2013 6:41 PM

If absolute best accuracy is wanted, coat the part with photoresist and
mount it on an accurate turntable. Set up an optical projector projecting
just one narrow line. Lock everything down and in a darkroom expose the
first line, change the turntable to the next line, expose and so on.

When done, the calibration accuracy is only limited by the turntable
accuracy, the centering of the part on the turntable and the roundness of
the part. The optical system never moved so it should be stable as long as
there are not any temperature gradients.

A second pass can be run projecting the numbers a required.

Bertho






[Non-text portions of this message have been removed]

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-24 by Rick Sparber

Bertho,

I have a full machine shop including a Gingery shaper which can cut these
tick marks. But my goal is to invent a new way to make a graduated dial.
Being able to etch a dial would be an advancement.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Boman33
Sent: Sunday, March 24, 2013 4:03 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

If you do not have a rotary table it is simple to make one since there is
zero force on the subject. A 100 tooth gear will give you accurate
indexing.

No art work is needed for the critical lines, either optical projection or a
laser line source.

Bertho

Re: etching the OD of a cylinder to create a graduated dial

2013-03-25 by KalleP

This will not work as is for a cylinder but for a conical scale it might work.

Instead of projecting a line and then indexing the dial you could look at some of the long wave UV photo cure polymers that are used for 3D stereo lithography. You would dip the scale in the resin, pull it out and project an image with a UV modified DLP video projector, no need to dry the resist as you would be hardening it in-situ with the UV image. Have to keep the projector as far as convenient to maximise the focus depth if you have a conical scale (long focus lens) but you could have arbitrary complexity of the artwork that could be changed on every scale.

You would rinse and post cure the resin and then try out various etching methods to get a good bite. You could paint fill and then strip the resin off with a suitable solvent.

This method might have some value in making DIY PCBs as well, I know there are very (very) expensive industrial machines that do just this and have many of these projectors and expose a 50mmx50mm square (or whatever) and scan across the material and have the image track the material motion to get a continuous scan while having a largish projection area (instead of a single laser spot or scan line that is too slow). Imagine a video projector and a simple jig to position a pcb in 50mm grid, you could manually project, move, project and expose arbitrary image. Using the 3D printing resins might be a way to do a wet photo resist at home but I have not tried it. The materials are still a bit expensive but the layer required for etch resist should be fairly affordable.

A Google search found these two interesting hits, the second is just an abstract unless you pay or are a member of some secret cabal.

http://maskless.com/High_Speed_MLI_TechPaper.pdf

http://www.researchgate.net/publication/24261077_Direct_projection_on_dry-film_photoresist_%28DP%282%29%29_do-it-yourself_three-dimensional_polymer_microfluidics

Regards

Kalle
--
Johannesburg, South Africa


--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:
>
> Bertho,
>
> I have a full machine shop including a Gingery shaper which can cut these
> tick marks. But my goal is to invent a new way to make a graduated dial.
> Being able to etch a dial would be an advancement.
>
> Rick
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> On Behalf Of Boman33
> Sent: Sunday, March 24, 2013 4:03 AM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
> graduated dial
>
> If you do not have a rotary table it is simple to make one since there is
> zero force on the subject. A 100 tooth gear will give you accurate
> indexing.
>
> No art work is needed for the critical lines, either optical projection or a
> laser line source.
>
> Bertho
>

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-25 by Rick Sparber

I am not ready to abandon contact printing.

On my first attempt, I plan to take some large diameter thin walled copper
pipe and slice off a 1/2" long piece. This will be heated so it expands and
then put down around a piece of steel round stock. As it cools, I will get a
thermal fit. That copper will not come off. Then I will machine the piece
true and face the end. A center hole will be drilled.

I next plan to coat the copper with photo resist and used a laser printed
mask to expose. Then I'll use ferric chloride for the etching and see how
deep I can get. This will prove out the concept of contact printing and
etching a cylinder.

If this works, I will play with electo etching with salt water directly on
steel. I know this process is much slower and tends to tear up the mask but
sure would be great if it works.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of KalleP
Sent: Monday, March 25, 2013 7:45 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

This will not work as is for a cylinder but for a conical scale it might
work.

Instead of projecting a line and then indexing the dial you could look at
some of the long wave UV photo cure polymers that are used for 3D stereo
lithography. You would dip the scale in the resin, pull it out and project
an image with a UV modified DLP video projector, no need to dry the resist
as you would be hardening it in-situ with the UV image. Have to keep the
projector as far as convenient to maximise the focus depth if you have a
conical scale (long focus lens) but you could have arbitrary complexity of
the artwork that could be changed on every scale.

You would rinse and post cure the resin and then try out various etching
methods to get a good bite. You could paint fill and then strip the resin
off with a suitable solvent.

This method might have some value in making DIY PCBs as well, I know there
are very (very) expensive industrial machines that do just this and have
many of these projectors and expose a 50mmx50mm square (or whatever) and
scan across the material and have the image track the material motion to get
a continuous scan while having a largish projection area (instead of a
single laser spot or scan line that is too slow). Imagine a video projector
and a simple jig to position a pcb in 50mm grid, you could manually project,
move, project and expose arbitrary image. Using the 3D printing resins
might be a way to do a wet photo resist at home but I have not tried it.
The materials are still a bit expensive but the layer required for etch
resist should be fairly affordable.

A Google search found these two interesting hits, the second is just an
abstract unless you pay or are a member of some secret cabal.

http://maskless.com/High_Speed_MLI_TechPaper.pdf

http://www.researchgate.net/publication/24261077_Direct_projection_on_dry-fi
lm_photoresist_%28DP%282%29%29_do-it-yourself_three-dimensional_polymer_micr
ofluidics

Regards

Kalle

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-25 by Boman33

Rick,

You can also try etching aluminum using lye.



I understand you desire to try new and different procedures but at the same
time what are your goals and tradeoffs? To me, the accuracy of a functional
(not decorative) scale is the most important requirement, then readability,
and I guess finally appearance.



Wrapping an artwork around a cylinder looks to me as an instant tradeoff in
accuracy.



Also to make initial testing easier, try your etching procedures on a piece
of flat metal and then afterwards progress to the cylinder.

Good luck and keep us up-to-date.

Bertho



From: Rick Sparber Sent: Monday, March 25, 2013 17:22



I am not ready to abandon contact printing.

On my first attempt, I plan to take some large diameter thin walled copper
pipe and slice off a 1/2" long piece. This will be heated so it expands and
then put down around a piece of steel round stock. As it cools, I will get a
thermal fit. That copper will not come off. Then I will machine the piece
true and face the end. A center hole will be drilled.

I next plan to coat the copper with photo resist and used a laser printed
mask to expose. Then I'll use ferric chloride for the etching and see how
deep I can get. This will prove out the concept of contact printing and
etching a cylinder.

If this works, I will play with electo etching with salt water directly on
steel. I know this process is much slower and tends to tear up the mask but
sure would be great if it works.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs%40yahoogroups.com>
[mailto:Homebrew_PCBs@yahoogroups.com
<mailto:Homebrew_PCBs%40yahoogroups.com> ]
On Behalf Of KalleP
Sent: Monday, March 25, 2013 7:45 AM
To: Homebrew_PCBs@yahoogroups.com <mailto:Homebrew_PCBs%40yahoogroups.com>
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

This will not work as is for a cylinder but for a conical scale it might
work.

Instead of projecting a line and then indexing the dial you could look at
some of the long wave UV photo cure polymers that are used for 3D stereo
lithography. You would dip the scale in the resin, pull it out and project
an image with a UV modified DLP video projector, no need to dry the resist
as you would be hardening it in-situ with the UV image. Have to keep the
projector as far as convenient to maximise the focus depth if you have a
conical scale (long focus lens) but you could have arbitrary complexity of
the artwork that could be changed on every scale.

You would rinse and post cure the resin and then try out various etching
methods to get a good bite. You could paint fill and then strip the resin
off with a suitable solvent.

This method might have some value in making DIY PCBs as well, I know there
are very (very) expensive industrial machines that do just this and have
many of these projectors and expose a 50mmx50mm square (or whatever) and
scan across the material and have the image track the material motion to get
a continuous scan while having a largish projection area (instead of a
single laser spot or scan line that is too slow). Imagine a video projector
and a simple jig to position a pcb in 50mm grid, you could manually project,
move, project and expose arbitrary image. Using the 3D printing resins
might be a way to do a wet photo resist at home but I have not tried it.
The materials are still a bit expensive but the layer required for etch
resist should be fairly affordable.

A Google search found these two interesting hits, the second is just an
abstract unless you pay or are a member of some secret cabal.

http://maskless.com/High_Speed_MLI_TechPaper.pdf

http://www.researchgate.net/publication/24261077_Direct_projection_on_dry-fi
lm_photoresist_%28DP%282%29%29_do-it-yourself_three-dimensional_polymer_micr
ofluidics

Regards

Kalle





[Non-text portions of this message have been removed]

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-25 by Rick Sparber

Bertho,

I will certainly try using lye on AL. Thanks!

My goal here is to "find stuff out" and hopefully figure out a new way to
make graduated dials for hobby machine tools. I know what contact printing
can do with circuit boards and it is impressive. So I don't think accuracy
will be a problem. If I can get clean, relatively deep features, then I will
be happy. I will then fill the recesses with a contrasting material like
nail polish.

I already wrapped artwork around cylinders as I did on my homemade metal
shaper:

http://rick.sparber.org/Articles/CD/CDM/d.pdf


It works fine but did take a lot of parts to do it. Much better to etch into
the metal.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Boman33
Sent: Monday, March 25, 2013 3:16 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

Rick,

You can also try etching aluminum using lye.



I understand you desire to try new and different procedures but at the same
time what are your goals and tradeoffs? To me, the accuracy of a functional
(not decorative) scale is the most important requirement, then readability,
and I guess finally appearance.



Wrapping an artwork around a cylinder looks to me as an instant tradeoff in
accuracy.



Also to make initial testing easier, try your etching procedures on a piece
of flat metal and then afterwards progress to the cylinder.

Good luck and keep us up-to-date.

Bertho

RE: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a graduated dial

2013-03-26 by Rick Sparber

Here is an update of my progress:

The spray on (negative type) photo resist and developer will arrive on
Thursday. In the mean time, I took some nominally 1.125 " diameter copper
pipe and cut off a 1/2" piece. Then I turned some cold rolled steel down for
an interference fit. I left a shoulder on the steel. I was then able to
force fit the soft copper onto the steel using my bench vise. Then I put the
assembly back on the lathe to true it all up and drill a center hole. My
finished outside diameter of 1.125" means my scale must be 3.545" long.

I then drew a 6" line with my CAD program and printed it out. To my
surprise, the printed line was 6.000" so no correction factor is needed. I
then drew a simple scale with 10 segments and 4 small tick marks per
segment. I also put numbers to the right of each segment line. After
printing out, I taped it to the OD of the copper and it was a perfect fit.

So next I will print it out on clear plastic, trim the excess, and wait for
the chemicals. If I understand the term "negative type" correctly, what is
black on the artwork will be copper free after etch. If true, that sure
saves toner.

Rick

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of KalleP
Sent: Monday, March 25, 2013 7:45 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: etching the OD of a cylinder to create a
graduated dial

This will not work as is for a cylinder but for a conical scale it might
work.

Instead of projecting a line and then indexing the dial you could look at
some of the long wave UV photo cure polymers that are used for 3D stereo
lithography. You would dip the scale in the resin, pull it out and project
an image with a UV modified DLP video projector, no need to dry the resist
as you would be hardening it in-situ with the UV image. Have to keep the
projector as far as convenient to maximise the focus depth if you have a
conical scale (long focus lens) but you could have arbitrary complexity of
the artwork that could be changed on every scale.

You would rinse and post cure the resin and then try out various etching
methods to get a good bite. You could paint fill and then strip the resin
off with a suitable solvent.

This method might have some value in making DIY PCBs as well, I know there
are very (very) expensive industrial machines that do just this and have
many of these projectors and expose a 50mmx50mm square (or whatever) and
scan across the material and have the image track the material motion to get
a continuous scan while having a largish projection area (instead of a
single laser spot or scan line that is too slow). Imagine a video projector
and a simple jig to position a pcb in 50mm grid, you could manually project,
move, project and expose arbitrary image. Using the 3D printing resins
might be a way to do a wet photo resist at home but I have not tried it.
The materials are still a bit expensive but the layer required for etch
resist should be fairly affordable.

A Google search found these two interesting hits, the second is just an
abstract unless you pay or are a member of some secret cabal.

http://maskless.com/High_Speed_MLI_TechPaper.pdf

http://www.researchgate.net/publication/24261077_Direct_projection_on_dry-fi
lm_photoresist_%28DP%282%29%29_do-it-yourself_three-dimensional_polymer_micr
ofluidics

Regards

Kalle
--
Johannesburg, South Africa