Homebrew_PCBs

Hi,
Nobody liked my light on a plotter idea. I was told the
light source would have to move too slow. The board would take
way to long. Ok, I use Mechanical Etching bits myself. But what
if you coated the whole board with resist. Then you put a sharp
point in the plotter. Have the plotter do isolation paths. Then
the board goes to the acid.

John

Yep, far too long to expose, and the problem of "blooming". UV
laser, anyone?

That sounds do-able! It would just require modifying a pen with one
of those carbide point marking pens. I think you could probably
just spray something like one coat of black fast drying laquer to
scratch through.

And one of the things I've always liked doing to boards I make is
sign them. Couldn't do that when I made some with the vinyl cutter.

So the only issues are paint that will scratch away cleanly and
that it leaves a wide enough opening after etching.

Steve Greenfield

--- crankorgan <john@...> wrote:

> Hi,
> Nobody liked my light on a plotter idea. I was told the
> light source would have to move too slow. The board would take
> way to long. Ok, I use Mechanical Etching bits myself. But what
> if you coated the whole board with resist. Then you put a sharp
> point in the plotter. Have the plotter do isolation paths. Then
> the board goes to the acid.
>
> John

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At 08:12 AM 04/05/2002 -0800, you wrote in part:

>So the only issues are paint that will scratch away cleanly and
>that it leaves a wide enough opening after etching.

Very interesting idea.
You could use layout fluid for metal working. Most are a lacquer type base
and scratch very cleanly since that's exactly what they're designed for.
Dykem is one manufacturer, it's available in a couple of colors, spray or
brush.
Denny

I'm finding John's idea pretty intriguing.
Just to take the brainstorming another step:
One big problem with PCB routers is tool life and their cost.
But using a CNC router with a cutter to just cut through the surface of the
resist and a thou or two in to the copper would prolong the life of a
carbide tool immensely... and produce a board that should etch quickly and
cleanly.
Yes it would be better do away with etching all together but a marriage of
the two technologies for some applications could be useful.
Denny


At 02:35 PM 04/05/2002 -0000, you wrote:

>Hi,
> Nobody liked my light on a plotter idea. I was told the
>light source would have to move too slow. The board would take
>way to long. Ok, I use Mechanical Etching bits myself. But what
>if you coated the whole board with resist. Then you put a sharp
>point in the plotter. Have the plotter do isolation paths. Then
>the board goes to the acid.
>
> John
>
>
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

Hi Steve,
I feel by using the Scratch and Etch method, pen speed
and flow will be out of the picture. Most software will allow the
outlining to be done. I don't acid etch here! But I got into it
trying to help someone else. I even bought a plotter. I bought the
plotter to see how it is made. I want to create a really cheap
PCBMill next. The one I sell plans for works great. I am looking
to cut the building time and cost way down. While working on the
new PCBMill the Light bulb idea hit. Then the Scratch and Etch
idea! I hope somebody will try it and report back.

John

--- In Homebrew_PCBs@y..., Steve Greenfield <alienrelics@y...> wrote:
> Yep, far too long to expose, and the problem of "blooming". UV
> laser, anyone?
>
> That sounds do-able! It would just require modifying a pen with one
> of those carbide point marking pens. I think you could probably
> just spray something like one coat of black fast drying laquer to
> scratch through.
>
> And one of the things I've always liked doing to boards I make is
> sign them. Couldn't do that when I made some with the vinyl cutter.
>
> So the only issues are paint that will scratch away cleanly and
> that it leaves a wide enough opening after etching.
>
> Steve Greenfield
>
> --- crankorgan <john@k...> wrote:
> > Hi,
> > Nobody liked my light on a plotter idea. I was told the
> > light source would have to move too slow. The board would take
> > way to long. Ok, I use Mechanical Etching bits myself. But what
> > if you coated the whole board with resist. Then you put a sharp
> > point in the plotter. Have the plotter do isolation paths. Then
> > the board goes to the acid.
> >
> > John
>
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Tax Center - online filing with TurboTax
> http://taxes.yahoo.com/

Hi Denny,
The acid will also stay strong because there
is less copper etched when doing isolation. I use the
Think and Tinker bits. They only last a little while
longer if you hit just the copper. I did all kinds
of tests trying to reduce my costs so I could see
circuit boards to the public. Hopefully someone
gives the Scratch and Etch a real test!

John

--- In Homebrew_PCBs@y..., milwiron@t... wrote:
>
> I'm finding John's idea pretty intriguing.
> Just to take the brainstorming another step:
> One big problem with PCB routers is tool life and their cost.
> But using a CNC router with a cutter to just cut through the
surface of the
> resist and a thou or two in to the copper would prolong the life of
a
> carbide tool immensely... and produce a board that should etch
quickly and
> cleanly.
> Yes it would be better do away with etching all together but a
marriage of
> the two technologies for some applications could be useful.
> Denny
>
>
> At 02:35 PM 04/05/2002 -0000, you wrote:
> >Hi,
> > Nobody liked my light on a plotter idea. I was told the
> >light source would have to move too slow. The board would take
> >way to long. Ok, I use Mechanical Etching bits myself. But what
> >if you coated the whole board with resist. Then you put a sharp
> >point in the plotter. Have the plotter do isolation paths. Then
> >the board goes to the acid.
> >
> > John
> >
> >
> >
> >To unsubscribe from this group, send an email to:
> >Homebrew_PCBs-unsubscribe@y...
> >
> >
> >
> >Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >

This might be a wierd idea, just say so if it is-

How about a pointed bit used in your PCB milling machine, with the
laquer coating and a bath in the etchant after? That guarantees a
wider swath but with less cutting.

I'm thinking of a guy who sells pictures etched into stone. His
bits are just carbide shafts ground to a slightly faceted point.
The idea being that this gives you a wider path through the copper,
and you can resharpen the bits. It does require the CNC milling
machine and etching afterwards, though, so perhaps complexity would
outweigh any cost savings.

I've gotta try your scratch and etch idea.

Steve Greenfield

--- crankorgan <john@...> wrote:

> Hi Denny,
> The acid will also stay strong because there
> is less copper etched when doing isolation. I use the
> Think and Tinker bits. They only last a little while
> longer if you hit just the copper. I did all kinds
> of tests trying to reduce my costs so I could see
> circuit boards to the public. Hopefully someone
> gives the Scratch and Etch a real test!
>
> John
>
> --- In Homebrew_PCBs@y..., milwiron@t... wrote:
> >
> > I'm finding John's idea pretty intriguing.
> > Just to take the brainstorming another step:
> > One big problem with PCB routers is tool life and their cost.
> > But using a CNC router with a cutter to just cut through the
> surface of the
> > resist and a thou or two in to the copper would prolong the
> life of
> a
> > carbide tool immensely... and produce a board that should etch
> quickly and
> > cleanly.
> > Yes it would be better do away with etching all together but a
> marriage of
> > the two technologies for some applications could be useful.
> > Denny
> >
> >
> > At 02:35 PM 04/05/2002 -0000, you wrote:
> > >Hi,
> > > Nobody liked my light on a plotter idea. I was told the
> > >light source would have to move too slow. The board would take
> > >way to long. Ok, I use Mechanical Etching bits myself. But
> what
> > >if you coated the whole board with resist. Then you put a
> sharp
> > >point in the plotter. Have the plotter do isolation paths.
> Then
> > >the board goes to the acid.
> > >
> > > John

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Steve,
In most software you can set the width of the milled
area or Isolation. When using a plotter, there will be less
drag if the point is fine.

Hey Steve! Thanks for this conference! I am having fun!

John

--- In Homebrew_PCBs@y..., Steve Greenfield <alienrelics@y...> wrote:
> This might be a wierd idea, just say so if it is-
>
> How about a pointed bit used in your PCB milling machine, with the
> laquer coating and a bath in the etchant after? That guarantees a
> wider swath but with less cutting.
>
> I'm thinking of a guy who sells pictures etched into stone. His
> bits are just carbide shafts ground to a slightly faceted point.
> The idea being that this gives you a wider path through the copper,
> and you can resharpen the bits. It does require the CNC milling
> machine and etching afterwards, though, so perhaps complexity would
> outweigh any cost savings.
>
> I've gotta try your scratch and etch idea.
>
> Steve Greenfield
>
> --- crankorgan <john@k...> wrote:
> > Hi Denny,
> > The acid will also stay strong because there
> > is less copper etched when doing isolation. I use the
> > Think and Tinker bits. They only last a little while
> > longer if you hit just the copper. I did all kinds
> > of tests trying to reduce my costs so I could see
> > circuit boards to the public. Hopefully someone
> > gives the Scratch and Etch a real test!
> >
> > John
> >
> > --- In Homebrew_PCBs@y..., milwiron@t... wrote:
> > >
> > > I'm finding John's idea pretty intriguing.
> > > Just to take the brainstorming another step:
> > > One big problem with PCB routers is tool life and their cost.
> > > But using a CNC router with a cutter to just cut through the
> > surface of the
> > > resist and a thou or two in to the copper would prolong the
> > life of
> > a
> > > carbide tool immensely... and produce a board that should etch
> > quickly and
> > > cleanly.
> > > Yes it would be better do away with etching all together but a
> > marriage of
> > > the two technologies for some applications could be useful.
> > > Denny
> > >
> > >
> > > At 02:35 PM 04/05/2002 -0000, you wrote:
> > > >Hi,
> > > > Nobody liked my light on a plotter idea. I was told the
> > > >light source would have to move too slow. The board would take
> > > >way to long. Ok, I use Mechanical Etching bits myself. But
> > what
> > > >if you coated the whole board with resist. Then you put a
> > sharp
> > > >point in the plotter. Have the plotter do isolation paths.
> > Then
> > > >the board goes to the acid.
> > > >
> > > > John
>
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Tax Center - online filing with TurboTax
> http://taxes.yahoo.com/

--- milwiron@... wrote:

> At 08:12 AM 04/05/2002 -0800, you wrote in part:
> >So the only issues are paint that will scratch away cleanly and
> >that it leaves a wide enough opening after etching.
>
> Very interesting idea.
> You could use layout fluid for metal working. Most are a lacquer
> type base
> and scratch very cleanly since that's exactly what they're
> designed for.
> Dykem is one manufacturer, it's available in a couple of colors,
> spray or
> brush.
> Denny

Great idea. Anyone here have some and some etchant and want to try
it and report back here? Nothing fancy, just coat a scrap of board
and then scratch the surface with the scratching device held at 90
degrees with only its own weight holding it down.

Steve Greenfield

__________________________________________________
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A friend of mine long ago claimed he used a week solution of nitric
acid for etching PCBs.

Has anyone here tried this?

I'm thinking I need an exhaust hood in my basement. I figured if I
use a fan then I have to worry about the fan being eaten by acid
fumes, so thought maybe I'd use my air compressor with a simple
homemade venturi pump made out of plastic pipe.

Whatdya think?

Steve Greenfield


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Hi Steve, John, list,

check out Jon E's photo plotter:

http://www.artsci.wustl.edu/~jmelson/photoplot.html

While it plots to film, I think you can get a few ideas from it. And
there are advantages if you can generate a good film, such as exposing
as many boards as you want from it.

But yes, I DO like the concept of mechanical etching! And the software
to do the isolation tool paths is very interesting to me (programmer).
As well as the controller it's self!

I don't know the linear speed of Jon's photo plotter (perhaps it's that
the film is faster then the photo resist), but I'm surprised it couldn't
be made to work. A laser out of an HP laser printer? Then you'd need a
mirror to get the light over to the "pen lens" and down to the board.
Put the hole laser thing on the XY carriage? Yeah, that could work!

Perhaps we'll get a little more info on the HP, and someone can try some
experiments on exposing the resist on a board with a laser! And who
cares if it takes a long time? Controlling the size of the laser "dot"
on the board with an aperture would be the tough part. I'm told that
commercial photo plotters use an aperture disk, which is a set of
"films" with an appropriate mask.


Alan KM6VV


Steve Greenfield wrote:

>
> Yep, far too long to expose, and the problem of "blooming". UV
> laser, anyone?
>
> That sounds do-able! It would just require modifying a pen with one
> of those carbide point marking pens. I think you could probably
> just spray something like one coat of black fast drying laquer to
> scratch through.
>
> And one of the things I've always liked doing to boards I make is
> sign them. Couldn't do that when I made some with the vinyl cutter.
>
> So the only issues are paint that will scratch away cleanly and
> that it leaves a wide enough opening after etching.
>
> Steve Greenfield
>
> --- crankorgan <john@...> wrote:
> > Hi,
> > Nobody liked my light on a plotter idea. I was told the
> > light source would have to move too slow. The board would take
> > way to long. Ok, I use Mechanical Etching bits myself. But what
> > if you coated the whole board with resist. Then you put a sharp
> > point in the plotter. Have the plotter do isolation paths. Then
> > the board goes to the acid.
> >
> > John
>

Denny, list,
Interesting idea, but.....
If you do scratch thru the coating and into the copper there will be a big
chance of under-etching. That is when the acid starts to etch in and under
the protective coating thus making the traces a lot thinner than they should
be.
/Henrik Olsson.

----- Original Message -----
From: <milwiron@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, April 05, 2002 6:46 PM
Subject: Re: [Homebrew_PCBs] Scratch and Etch


>
> I'm finding John's idea pretty intriguing.
> Just to take the brainstorming another step:
> One big problem with PCB routers is tool life and their cost.
> But using a CNC router with a cutter to just cut through the surface of
the
> resist and a thou or two in to the copper would prolong the life of a
> carbide tool immensely... and produce a board that should etch quickly and
> cleanly.
> Yes it would be better do away with etching all together but a marriage of
> the two technologies for some applications could be useful.
> Denny
>
>
> At 02:35 PM 04/05/2002 -0000, you wrote:
> >Hi,
> > Nobody liked my light on a plotter idea. I was told the
> >light source would have to move too slow. The board would take
> >way to long. Ok, I use Mechanical Etching bits myself. But what
> >if you coated the whole board with resist. Then you put a sharp
> >point in the plotter. Have the plotter do isolation paths. Then
> >the board goes to the acid.
> >
> > John
> >
> >
> >
> >To unsubscribe from this group, send an email to:
> >Homebrew_PCBs-unsubscribe@yahoogroups.com
> >
> >
> >
> >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

Yes, but that happens anyway. You'll only be etching out a narrow
channel to start with, so I can't see it being any more of a
problem than etching the "normal" way.

Steve Greenfield

--- Henrik Olsson <henrik-olsson@...> wrote:

> Denny, list,
> Interesting idea, but.....
> If you do scratch thru the coating and into the copper there will
> be a big
> chance of under-etching. That is when the acid starts to etch in
> and under
> the protective coating thus making the traces a lot thinner than
> they should
> be.
> /Henrik Olsson.
>
> ----- Original Message -----
> From: <milwiron@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Friday, April 05, 2002 6:46 PM
> Subject: Re: [Homebrew_PCBs] Scratch and Etch
>
>
> >
> > I'm finding John's idea pretty intriguing.
> > Just to take the brainstorming another step:
> > One big problem with PCB routers is tool life and their cost.
> > But using a CNC router with a cutter to just cut through the
> surface of
> the
> > resist and a thou or two in to the copper would prolong the
> life of a
> > carbide tool immensely... and produce a board that should etch
> quickly and
> > cleanly.
> > Yes it would be better do away with etching all together but a
> marriage of
> > the two technologies for some applications could be useful.
> > Denny
> >
> >
> > At 02:35 PM 04/05/2002 -0000, you wrote:
> > >Hi,
> > > Nobody liked my light on a plotter idea. I was told the
> > >light source would have to move too slow. The board would take
> > >way to long. Ok, I use Mechanical Etching bits myself. But
> what
> > >if you coated the whole board with resist. Then you put a
> sharp
> > >point in the plotter. Have the plotter do isolation paths.
> Then
> > >the board goes to the acid.
> > >
> > > John
> > >
> > >
> > >
> > >To unsubscribe from this group, send an email to:
> > >Homebrew_PCBs-unsubscribe@yahoogroups.com
> > >
> > >
> > >
> > >Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To unsubscribe from this group, send an email to:
> > Homebrew_PCBs-unsubscribe@yahoogroups.com
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> >
> >
>
>
> ------------------------ Yahoo! Groups Sponsor
>
> To unsubscribe from this group, send an email to:
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>
>
>
> Your use of Yahoo! Groups is subject to
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>
>

=====
Steve Greenfield // Digital photo scanning, retouching,
Polymorph Digital Photography // and photomorphing to your specs.
253/318-2473 voice // We use the best little computer in
polymorph@... // the world, the Amiga!
http://www.polyphoto.com/ // Based in Tacoma, WA, USA

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--- Alan Marconett KM6VV <KM6VV@...> wrote:

> Hi Steve, John, list,
>
> check out Jon E's photo plotter:
>
> http://www.artsci.wustl.edu/~jmelson/photoplot.html

His new website has more info on it:

http://pico-systems.com/

Check out "Machining", too, it has more info including the photo
plotter.

Steve Greenfield

__________________________________________________
Do You Yahoo!?
Yahoo! Tax Center - online filing with TurboTax
http://taxes.yahoo.com/

Hi Alan,
I built a similar unit for receiving Radio Faxes
from around the world VIA a shortwave radio. My unit used
stepping motors from a floppy. That's 20 years ago! Here
is a picture of the unit. I used some of Ralph Taggerts
circuits and some of my own. I went on to design a circuit
board that goes in the computer. I used FAX_Dhals.

see machine at:

http://crankorgan.com/kleinfax.JPG


73s

John

--- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi Steve, John, list,
>
> check out Jon E's photo plotter:
>
> http://www.artsci.wustl.edu/~jmelson/photoplot.html
>
> While it plots to film, I think you can get a few ideas from it.
And
> there are advantages if you can generate a good film, such as
exposing
> as many boards as you want from it.
>
> But yes, I DO like the concept of mechanical etching! And the
software
> to do the isolation tool paths is very interesting to me
(programmer).
> As well as the controller it's self!
>
> I don't know the linear speed of Jon's photo plotter (perhaps it's
that
> the film is faster then the photo resist), but I'm surprised it
couldn't
> be made to work. A laser out of an HP laser printer? Then you'd
need a
> mirror to get the light over to the "pen lens" and down to the
board.
> Put the hole laser thing on the XY carriage? Yeah, that could work!
>
> Perhaps we'll get a little more info on the HP, and someone can try
some
> experiments on exposing the resist on a board with a laser! And who
> cares if it takes a long time? Controlling the size of the
laser "dot"
> on the board with an aperture would be the tough part. I'm told
that
> commercial photo plotters use an aperture disk, which is a set of
> "films" with an appropriate mask.
>
>
> Alan KM6VV
>
>
> Steve Greenfield wrote:
> >
> > Yep, far too long to expose, and the problem of "blooming". UV
> > laser, anyone?
> >
> > That sounds do-able! It would just require modifying a pen with
one
> > of those carbide point marking pens. I think you could probably
> > just spray something like one coat of black fast drying laquer to
> > scratch through.
> >
> > And one of the things I've always liked doing to boards I make is
> > sign them. Couldn't do that when I made some with the vinyl
cutter.
> >
> > So the only issues are paint that will scratch away cleanly and
> > that it leaves a wide enough opening after etching.
> >
> > Steve Greenfield
> >
> > --- crankorgan <john@k...> wrote:
> > > Hi,
> > > Nobody liked my light on a plotter idea. I was told the
> > > light source would have to move too slow. The board would take
> > > way to long. Ok, I use Mechanical Etching bits myself. But what
> > > if you coated the whole board with resist. Then you put a sharp
> > > point in the plotter. Have the plotter do isolation paths. Then
> > > the board goes to the acid.
> > >
> > > John
> >

Hi John,

Yes! I have Taggert's book, and I played around with weather fax's, but
AFTER CRT's were common. what is FAX_Dhals? A software package?

73's,

Alan KM6VV


crankorgan wrote:

>
> Hi Alan,
> I built a similar unit for receiving Radio Faxes
> from around the world VIA a shortwave radio. My unit used
> stepping motors from a floppy. That's 20 years ago! Here
> is a picture of the unit. I used some of Ralph Taggerts
> circuits and some of my own. I went on to design a circuit
> board that goes in the computer. I used FAX_Dhals.
>
> see machine at:
>
> http://crankorgan.com/kleinfax.JPG
>
> 73s
>
> John
>
> --- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Steve, John, list,
> >
> > check out Jon E's photo plotter:
> >
> > http://www.artsci.wustl.edu/~jmelson/photoplot.html
> >
> > While it plots to film, I think you can get a few ideas from it.
> And
> > there are advantages if you can generate a good film, such as
> exposing
> > as many boards as you want from it.
> >
> > But yes, I DO like the concept of mechanical etching! And the
> software
> > to do the isolation tool paths is very interesting to me
> (programmer).
> > As well as the controller it's self!
> >
> > I don't know the linear speed of Jon's photo plotter (perhaps it's
> that
> > the film is faster then the photo resist), but I'm surprised it
> couldn't
> > be made to work. A laser out of an HP laser printer? Then you'd
> need a
> > mirror to get the light over to the "pen lens" and down to the
> board.
> > Put the hole laser thing on the XY carriage? Yeah, that could work!
> >
> > Perhaps we'll get a little more info on the HP, and someone can try
> some
> > experiments on exposing the resist on a board with a laser! And who
> > cares if it takes a long time? Controlling the size of the
> laser "dot"
> > on the board with an aperture would be the tough part. I'm told
> that
> > commercial photo plotters use an aperture disk, which is a set of
> > "films" with an appropriate mask.
> >
> >
> > Alan KM6VV
> >
> >
> > Steve Greenfield wrote:
> > >
> > > Yep, far too long to expose, and the problem of "blooming". UV
> > > laser, anyone?
> > >
> > > That sounds do-able! It would just require modifying a pen with
> one
> > > of those carbide point marking pens. I think you could probably
> > > just spray something like one coat of black fast drying laquer to
> > > scratch through.
> > >
> > > And one of the things I've always liked doing to boards I make is
> > > sign them. Couldn't do that when I made some with the vinyl
> cutter.
> > >
> > > So the only issues are paint that will scratch away cleanly and
> > > that it leaves a wide enough opening after etching.
> > >
> > > Steve Greenfield
> > >
> > > --- crankorgan <john@k...> wrote:
> > > > Hi,
> > > > Nobody liked my light on a plotter idea. I was told the
> > > > light source would have to move too slow. The board would take
> > > > way to long. Ok, I use Mechanical Etching bits myself. But what
> > > > if you coated the whole board with resist. Then you put a sharp
> > > > point in the plotter. Have the plotter do isolation paths. Then
> > > > the board goes to the acid.
> > > >
> > > > John

Alan,
Ralph had a BBS that I used to visit. I drew up his
ZipZap antenna as a ZIP package. Fax Dahl was software
that would turn Fax audio from my R71a to VGA images.
Later on there was a German Freeware program that would
work through the serial port with only a few resistors
and an opamp. If you do a search for Kleinfax on the net
you may find my diagram for turning a serial board into
a radio fax board. JFax killed my design off! I think
later versions of HamCom did fax too! That was a long time
ago.
After using steppers to spin my drum, I made a spinning
mirror camera like the ones the satellites use. Now I use
steppers to run my PCBMill. I mill circuit boards as part of
my business. There is no cheap way to make a 4" x 6" board. I
stick with the milling process because it works best for me.


John

--- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi John,
>
> Yes! I have Taggert's book, and I played around with weather
fax's, but
> AFTER CRT's were common. what is FAX_Dhals? A software package?
>
> 73's,
>
> Alan KM6VV
>
>
> crankorgan wrote:
> >
> > Hi Alan,
> > I built a similar unit for receiving Radio Faxes
> > from around the world VIA a shortwave radio. My unit used
> > stepping motors from a floppy. That's 20 years ago! Here
> > is a picture of the unit. I used some of Ralph Taggerts
> > circuits and some of my own. I went on to design a circuit
> > board that goes in the computer. I used FAX_Dhals.
> >
> > see machine at:
> >
> > http://crankorgan.com/kleinfax.JPG
> >
> > 73s
> >
> > John
> >
> > --- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...>
wrote:
> > > Hi Steve, John, list,
> > >
> > > check out Jon E's photo plotter:
> > >
> > > http://www.artsci.wustl.edu/~jmelson/photoplot.html
> > >
> > > While it plots to film, I think you can get a few ideas from it.
> > And
> > > there are advantages if you can generate a good film, such as
> > exposing
> > > as many boards as you want from it.
> > >
> > > But yes, I DO like the concept of mechanical etching! And the
> > software
> > > to do the isolation tool paths is very interesting to me
> > (programmer).
> > > As well as the controller it's self!
> > >
> > > I don't know the linear speed of Jon's photo plotter (perhaps
it's
> > that
> > > the film is faster then the photo resist), but I'm surprised it
> > couldn't
> > > be made to work. A laser out of an HP laser printer? Then
you'd
> > need a
> > > mirror to get the light over to the "pen lens" and down to the
> > board.
> > > Put the hole laser thing on the XY carriage? Yeah, that could
work!
> > >
> > > Perhaps we'll get a little more info on the HP, and someone can
try
> > some
> > > experiments on exposing the resist on a board with a laser!
And who
> > > cares if it takes a long time? Controlling the size of the
> > laser "dot"
> > > on the board with an aperture would be the tough part. I'm told
> > that
> > > commercial photo plotters use an aperture disk, which is a set
of
> > > "films" with an appropriate mask.
> > >
> > >
> > > Alan KM6VV
> > >
> > >
> > > Steve Greenfield wrote:
> > > >
> > > > Yep, far too long to expose, and the problem of "blooming". UV
> > > > laser, anyone?
> > > >
> > > > That sounds do-able! It would just require modifying a pen
with
> > one
> > > > of those carbide point marking pens. I think you could
probably
> > > > just spray something like one coat of black fast drying
laquer to
> > > > scratch through.
> > > >
> > > > And one of the things I've always liked doing to boards I
make is
> > > > sign them. Couldn't do that when I made some with the vinyl
> > cutter.
> > > >
> > > > So the only issues are paint that will scratch away cleanly
and
> > > > that it leaves a wide enough opening after etching.
> > > >
> > > > Steve Greenfield
> > > >
> > > > --- crankorgan <john@k...> wrote:
> > > > > Hi,
> > > > > Nobody liked my light on a plotter idea. I was told the
> > > > > light source would have to move too slow. The board would
take
> > > > > way to long. Ok, I use Mechanical Etching bits myself. But
what
> > > > > if you coated the whole board with resist. Then you put a
sharp
> > > > > point in the plotter. Have the plotter do isolation paths.
Then
> > > > > the board goes to the acid.
> > > > >
> > > > > John

http://www.dupont.com/pcm/riston/laserseries/fundamentals.html
http://www.anvik.com/results.html

Steve Greenfield wrote:

>
> Yep, far too long to expose, and the problem of "blooming". UV
> laser, anyone?
>
> That sounds do-able! It would just require modifying a pen with one
> of those carbide point marking pens. I think you could probably
> just spray something like one coat of black fast drying laquer to
> scratch through.
>
> And one of the things I've always liked doing to boards I make is
> sign them. Couldn't do that when I made some with the vinyl cutter.
>
> So the only issues are paint that will scratch away cleanly and
> that it leaves a wide enough opening after etching.
>
> Steve Greenfield
>
> --- crankorgan <john@...> wrote:
> > Hi,
> > Nobody liked my light on a plotter idea. I was told the
> > light source would have to move too slow. The board would take
> > way to long. Ok, I use Mechanical Etching bits myself. But what
> > if you coated the whole board with resist. Then you put a sharp
> > point in the plotter. Have the plotter do isolation paths. Then
> > the board goes to the acid.

You could have a fibre-optic cable close to the pcb resist putting
out high power. Could also try lens focusing with enough power to
speed the exposure.

Hello Steve, John and All,
I had to run a sample of a redesigned board Saturday morning so I tried a
simple Scratch and Etch test of John's idea.
Here are some fast notes:
I coated a small piece of 1 oz. single sided board stock with Dykem metal
layout fluid. (I did clean the board first with 320 wet or dry and a quick
wipe with lacquer thinner. Scribing lines through layout fluid coating
produces very clean marks with no chipping
A metal-scriber's weight alone is not quite enough to get a line down to
the copper, a little extra weight was needed. A light spring loading on the
plotter would probably be fine.
I also scribed some thicker lines with a 1/16" inch wide tool I had laying
on my bench.
The board was etched in Sodium Persulfate at 120 degrees F.
The Dykem layout fluid had no problem as a resist, in fact I'll probably
fill a pen and start using it to repair bad resist areas on proto boards.
Bottom line: The resulting etched scribe lines came out beautifully and the
Dykem cleans off easily with Scotch Brite or some light wet or dry sanding.
My only minor concern is the narrowness of the isolations produced by a
pointed scriber and soldering using a set of eyes that ain't what they were
10 years ago.
Denny

>> Very interesting idea.
>> You could use layout fluid for metal working. Most are a lacquer
>> type base
>> and scratch very cleanly since that's exactly what they're
>> designed for.
>> Dykem is one manufacturer, it's available in a couple of colors,
>> spray or
>> brush.
>> Denny
>
>Great idea. Anyone here have some and some etchant and want to try
>it and report back here? Nothing fancy, just coat a scrap of board
>and then scratch the surface with the scratching device held at 90
>degrees with only its own weight holding it down.
>
>Steve Greenfield
>
>__________________________________________________
>Do You Yahoo!?
>Yahoo! Tax Center - online filing with TurboTax
>http://taxes.yahoo.com/
>
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

Hi John,

I recall the JFax, and AEA's fax. Milling PCB's is quite a challenge,
and even more interesting!

I didn't quite get the "scratch and etch". This is for isolation, like
milling? Just enough to remove resist?

What about a burnishing bit, perhaps abrasive, to scrub off resist? It
would have to be quite small dia. Just mill through the resist.

Alan KM6VV


crankorgan wrote:

>
> Alan,
> Ralph had a BBS that I used to visit. I drew up his
> ZipZap antenna as a ZIP package. Fax Dahl was software
> that would turn Fax audio from my R71a to VGA images.
> Later on there was a German Freeware program that would
> work through the serial port with only a few resistors
> and an opamp. If you do a search for Kleinfax on the net
> you may find my diagram for turning a serial board into
> a radio fax board. JFax killed my design off! I think
> later versions of HamCom did fax too! That was a long time
> ago.
> After using steppers to spin my drum, I made a spinning
> mirror camera like the ones the satellites use. Now I use
> steppers to run my PCBMill. I mill circuit boards as part of
> my business. There is no cheap way to make a 4" x 6" board. I
> stick with the milling process because it works best for me.
>
> John
>
>
> --- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi John,
> >
> > Yes! I have Taggert's book, and I played around with weather
> fax's, but
> > AFTER CRT's were common. what is FAX_Dhals? A software package?
> >
> > 73's,
> >
> > Alan KM6VV

Denny,
Great job! When the idea hit me I was working on a 4 axis
4 wire controller board. I try to be innovative. Like I said in
my first message. I am here to help out! I goofed by sending
people to a picture of an etched board I did. The problem was
I used the location of a page on my website instead of the
picture. I only wanted people to know I really mill circuit
boards for a living using a Dremel. I also use cheap 1/4-20 threaded
rod for all my machines. In the right hands Scratch and Etch will
be lots of fun! A cheap plotter and some isolation software.

Good work Denny!

John

--- In Homebrew_PCBs@y..., milwiron@t... wrote:
>
> Hello Steve, John and All,
> I had to run a sample of a redesigned board Saturday morning so I
tried a
> simple Scratch and Etch test of John's idea.
> Here are some fast notes:
> I coated a small piece of 1 oz. single sided board stock with Dykem
metal
> layout fluid. (I did clean the board first with 320 wet or dry and
a quick
> wipe with lacquer thinner. Scribing lines through layout fluid
coating
> produces very clean marks with no chipping
> A metal-scriber's weight alone is not quite enough to get a line
down to
> the copper, a little extra weight was needed. A light spring
loading on the
> plotter would probably be fine.
> I also scribed some thicker lines with a 1/16" inch wide tool I had
laying
> on my bench.
> The board was etched in Sodium Persulfate at 120 degrees F.
> The Dykem layout fluid had no problem as a resist, in fact I'll
probably
> fill a pen and start using it to repair bad resist areas on proto
boards.
> Bottom line: The resulting etched scribe lines came out beautifully
and the
> Dykem cleans off easily with Scotch Brite or some light wet or dry
sanding.
> My only minor concern is the narrowness of the isolations produced
by a
> pointed scriber and soldering using a set of eyes that ain't what
they were
> 10 years ago.
> Denny
>
>
>
> >> Very interesting idea.
> >> You could use layout fluid for metal working. Most are a lacquer
> >> type base
> >> and scratch very cleanly since that's exactly what they're
> >> designed for.
> >> Dykem is one manufacturer, it's available in a couple of colors,
> >> spray or
> >> brush.
> >> Denny
> >
> >Great idea. Anyone here have some and some etchant and want to try
> >it and report back here? Nothing fancy, just coat a scrap of board
> >and then scratch the surface with the scratching device held at 90
> >degrees with only its own weight holding it down.
> >
> >Steve Greenfield
> >
> >__________________________________________________
> >Do You Yahoo!?
> >Yahoo! Tax Center - online filing with TurboTax
> >http://taxes.yahoo.com/
> >
> >
> >To unsubscribe from this group, send an email to:
> >Homebrew_PCBs-unsubscribe@y...
> >
> >
> >
> >Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >

Hi Alan,
I think Denny nailed it! Yes I am talking isolation. You
only etch a thin line between traces. Or you can have the point
go around a second time and make the isolation wider. Second option
is a wider tool. The coating Denny is using does not need
burnishing. If you have worked sheet metal, there is a coating you
put on the metal. Then you scribe you layout lines. The lines show
up against the dark coating. This is methode can be used to make
very precise parts.

John

--- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi John,
>
> I recall the JFax, and AEA's fax. Milling PCB's is quite a
challenge,
> and even more interesting!
>
> I didn't quite get the "scratch and etch". This is for isolation,
like
> milling? Just enough to remove resist?
>
> What about a burnishing bit, perhaps abrasive, to scrub off
resist? It
> would have to be quite small dia. Just mill through the resist.
>
> Alan KM6VV
>
>
> crankorgan wrote:
> >
> > Alan,
> > Ralph had a BBS that I used to visit. I drew up his
> > ZipZap antenna as a ZIP package. Fax Dahl was software
> > that would turn Fax audio from my R71a to VGA images.
> > Later on there was a German Freeware program that would
> > work through the serial port with only a few resistors
> > and an opamp. If you do a search for Kleinfax on the net
> > you may find my diagram for turning a serial board into
> > a radio fax board. JFax killed my design off! I think
> > later versions of HamCom did fax too! That was a long time
> > ago.
> > After using steppers to spin my drum, I made a spinning
> > mirror camera like the ones the satellites use. Now I use
> > steppers to run my PCBMill. I mill circuit boards as part of
> > my business. There is no cheap way to make a 4" x 6" board. I
> > stick with the milling process because it works best for me.
> >
> > John
> >
> >
> > --- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...>
wrote:
> > > Hi John,
> > >
> > > Yes! I have Taggert's book, and I played around with weather
> > fax's, but
> > > AFTER CRT's were common. what is FAX_Dhals? A software
package?
> > >
> > > 73's,
> > >
> > > Alan KM6VV

Steve Greenfield wrote:

> A friend of mine long ago claimed he used a week solution of nitric
> acid for etching PCBs.
>
> Has anyone here tried this?
>
> I'm thinking I need an exhaust hood in my basement. I figured if I
> use a fan then I have to worry about the fan being eaten by acid
> fumes, so thought maybe I'd use my air compressor with a simple
> homemade venturi pump made out of plastic pipe.
>
> Whatdya think?
>
> Steve Greenfield

Nitric acid is a controlled substance in Australia. Its not something I would
like to have around the house or garage. Do you know the byproducts from
copper and nitric acid ? There are many safer and much more usable etchants
around. If you are having troubles with a particular etchant then it could be
that your etching equipment/process needs improving. The chemistry is only
half the story.

Hey John,
Thank you for the kind words. A router is still the path for me but I think
you've come up with an excellent idea for people who want to use plotters
for resist work.
Just as a little follow-up:
A light pressure scribe line produced an isolation area .006" wide. At this
width it's very important to make sure etchant doesn't leave behind any
tiny hair width bridges across the isolation. Brushing the surface with a
soft brush during etching to make sure all these small areas "wet" worked
well and eliminated the hair size bridges.

A slightly heavier scribe, or going over the same area lightly twice with
the point, produced an isolation area .011" wide. No bridges across the
isolation lines were found.

Again, this was etching with sodium persulfate at 120 degrees F.and using
Dykem Steel Blue layout fluid as a resist.
Denny

At 07:24 PM 04/06/2002 -0000, you wrote:

>Denny,
> Great job! When the idea hit me I was working on a 4 axis
>4 wire controller board. I try to be innovative. Like I said in
>my first message. I am here to help out! I goofed by sending
>people to a picture of an etched board I did. The problem was
>I used the location of a page on my website instead of the
>picture. I only wanted people to know I really mill circuit
>boards for a living using a Dremel. I also use cheap 1/4-20 threaded
>rod for all my machines. In the right hands Scratch and Etch will
>be lots of fun! A cheap plotter and some isolation software.
>
> Good work Denny!
>
> John
>
>
>
>--- In Homebrew_PCBs@y..., milwiron@t... wrote:
>>
>> Hello Steve, John and All,
>> I had to run a sample of a redesigned board Saturday morning so I
>tried a
>> simple Scratch and Etch test of John's idea.
>> Here are some fast notes:
>> I coated a small piece of 1 oz. single sided board stock with Dykem
>metal
>> layout fluid. (I did clean the board first with 320 wet or dry and
>a quick
>> wipe with lacquer thinner. Scribing lines through layout fluid
>coating
>> produces very clean marks with no chipping
>> A metal-scriber's weight alone is not quite enough to get a line
>down to
>> the copper, a little extra weight was needed. A light spring
>loading on the
>> plotter would probably be fine.
>> I also scribed some thicker lines with a 1/16" inch wide tool I had
>laying
>> on my bench.
>> The board was etched in Sodium Persulfate at 120 degrees F.
>> The Dykem layout fluid had no problem as a resist, in fact I'll
>probably
>> fill a pen and start using it to repair bad resist areas on proto
>boards.
>> Bottom line: The resulting etched scribe lines came out beautifully
>and the
>> Dykem cleans off easily with Scotch Brite or some light wet or dry
>sanding.
>> My only minor concern is the narrowness of the isolations produced
>by a
>> pointed scriber and soldering using a set of eyes that ain't what
>they were
>> 10 years ago.
>> Denny
>>
>>
>>
>> >> Very interesting idea.
>> >> You could use layout fluid for metal working. Most are a lacquer
>> >> type base
>> >> and scratch very cleanly since that's exactly what they're
>> >> designed for.
>> >> Dykem is one manufacturer, it's available in a couple of colors,
>> >> spray or
>> >> brush.
>> >> Denny
>> >
>> >Great idea. Anyone here have some and some etchant and want to try
>> >it and report back here? Nothing fancy, just coat a scrap of board
>> >and then scratch the surface with the scratching device held at 90
>> >degrees with only its own weight holding it down.
>> >
>> >Steve Greenfield
>> >
>> >__________________________________________________
>> >Do You Yahoo!?
>> >Yahoo! Tax Center - online filing with TurboTax
>> >http://taxes.yahoo.com/
>> >
>> >
>> >To unsubscribe from this group, send an email to:
>> >Homebrew_PCBs-unsubscribe@y...
>> >
>> >
>> >
>> >Your use of Yahoo! Groups is subject to
>http://docs.yahoo.com/info/terms/
>> >
>> >
>
>
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

If you are looking to go to a film there is a very nice product sold by
M&R Marking. It is a negative film system that has extremely easy to use
water based chemistry. To produce a film you print a positive image
using a standard printer (I have always done it on a laser, but an
inkjet would likely work). You then do a contact print using standard
black light bulbs onto the negative film. Now to develop it you just
spray on a water based fluid from a squirt bottle and wait 90 seconds
then rinse and scrub the film under cool water with a paper towel. The
result is a completely negative film that is as opaque as the films I
have had done by a commercial photo plotter. Product info at:
http://www.mrmarking.com/phnegs.html

Tim
[Denver ,CO]

> While it plots to film, I think you can get a few ideas from
> it. And there are advantages if you can generate a good
> film, such as exposing as many boards as you want from it.

Added to the bookmarks!

Steve

--- Tim Goldstein <timg@...> wrote:

> If you are looking to go to a film there is a very nice product
> sold by
> M&R Marking. It is a negative film system that has extremely easy
> to use
> water based chemistry. To produce a film you print a positive
> image
> using a standard printer (I have always done it on a laser, but
> an
> inkjet would likely work). You then do a contact print using
> standard
> black light bulbs onto the negative film. Now to develop it you
> just
> spray on a water based fluid from a squirt bottle and wait 90
> seconds
> then rinse and scrub the film under cool water with a paper
> towel. The
> result is a completely negative film that is as opaque as the
> films I
> have had done by a commercial photo plotter. Product info at:
> http://www.mrmarking.com/phnegs.html

__________________________________________________
Do You Yahoo!?
Yahoo! Tax Center - online filing with TurboTax
http://taxes.yahoo.com/

I've been working this way a few times, manually (have no plotter yet) using
some kind of dentist tool, nearly 6000rpm, round-tipped cutter.
Just coat the board with thin layer of lacquer and "draw" all that you need
with light strokes of the cutter.
It will make nice, sharp edges, width of insulation path depends on cutter.

If you want only to scratch the lacquer with sharp-tipped tool, the
insulation paths will be too narrow and the lacquer can crack near the
edges. It will never happen if using rotating tool.

So the idea is to use fast-spinning tool with round tip, you need only to
push it lightly against the board, so it can be done very quickly and
easily.

The other technique I have heard of is similar, only the traces are "milled"
when there must be copper not where insulation will be. After that the board
must be tin-plated. Then wash away the lacquer and etch the board in some
kind of solution. Just I don't remember which one of the most popular
etchant solutions doesn't dissolve tin. But it wasn't anything very special.

KPL

Hi KPL,
You are using the wrong coating if it cracks. See
Denny's post! I mill circuit boards all the time. The
idea of Scratch and Etch came to me the other day. Mechanical
Etching bits have a limited life. Using the Scratch and
Etch method should be faster and cheaper for the home hobbiest.

John

--- In Homebrew_PCBs@y..., "Karlis" <krahabors@h...> wrote:
> I've been working this way a few times, manually (have no plotter
yet) using
> some kind of dentist tool, nearly 6000rpm, round-tipped cutter.
> Just coat the board with thin layer of lacquer and "draw" all that
you need
> with light strokes of the cutter.
> It will make nice, sharp edges, width of insulation path depends on
cutter.
>
> If you want only to scratch the lacquer with sharp-tipped tool, the
> insulation paths will be too narrow and the lacquer can crack near
the
> edges. It will never happen if using rotating tool.
>
> So the idea is to use fast-spinning tool with round tip, you need
only to
> push it lightly against the board, so it can be done very quickly
and
> easily.
>
> The other technique I have heard of is similar, only the traces
are "milled"
> when there must be copper not where insulation will be. After that
the board
> must be tin-plated. Then wash away the lacquer and etch the board
in some
> kind of solution. Just I don't remember which one of the most
popular
> etchant solutions doesn't dissolve tin. But it wasn't anything very
special.
>
> KPL

--- crankorgan <john@...> wrote:

> Hi KPL,
> You are using the wrong coating if it cracks. See
> Denny's post! I mill circuit boards all the time. The
> idea of Scratch and Etch came to me the other day. Mechanical
> Etching bits have a limited life. Using the Scratch and
> Etch method should be faster and cheaper for the home hobbiest.

Yeah! And very little to modify a plotter. Just take an empty pen
and drill out the center to fit a carbide tipped pen. Maybe cut off
most of the carbide pen to reduce the mass and so it fits within
the body of the pen.

I like the idea of just running it twice to widen the tracks and
ensure no bridges.

I have a couple of HP plotters here. Both unfortunately need some
work, one shuts down after about 10 seconds of plotting, the other
seems to slip, making angles into wierd curvy things. But good
enough to test the idea on.

Steve Greenfield


__________________________________________________
Do You Yahoo!?
Yahoo! Tax Center - online filing with TurboTax
http://taxes.yahoo.com/

Hi Steve,
I am redoing one of my controller boards. It
will now drive 4 wire motors. I am drawing the isolation
paths in TurbCad. People ask me why I don't use Eagle
or one of the other programs. The reason is I can do
things with TurboCad those packages won't let me do!
Everybody has their favorite method. Scratch and
Etch is not for everybody. I just know that people who
use a plotter with a pen to layout their boards will
find the Scratch and Etch better. I found my pen
sometimes skips. Coating the board and Scratching off
the coating allows more control. More testing is needed
by people with open minds. They say if you build a better
mouse trap, people will beat a path to your door. The
truth is build a mouse trap that is as good and cheaper!

John

--- In Homebrew_PCBs@y..., Steve Greenfield <alienrelics@y...> wrote:
> --- crankorgan <john@k...> wrote:
> > Hi KPL,
> > You are using the wrong coating if it cracks. See
> > Denny's post! I mill circuit boards all the time. The
> > idea of Scratch and Etch came to me the other day. Mechanical
> > Etching bits have a limited life. Using the Scratch and
> > Etch method should be faster and cheaper for the home hobbiest.
>
> Yeah! And very little to modify a plotter. Just take an empty pen
> and drill out the center to fit a carbide tipped pen. Maybe cut off
> most of the carbide pen to reduce the mass and so it fits within
> the body of the pen.
>
> I like the idea of just running it twice to widen the tracks and
> ensure no bridges.
>
> I have a couple of HP plotters here. Both unfortunately need some
> work, one shuts down after about 10 seconds of plotting, the other
> seems to slip, making angles into wierd curvy things. But good
> enough to test the idea on.
>
> Steve Greenfield
>
>
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