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PCB EDM -- further thoughts

PCB EDM -- further thoughts

2005-07-06 by curt_rxr

Hi All,

Stefan and Bengt were interested in my attempts to configure an EDM
PCB milling machine. Since my machine was built using surplus from my
lab's research efforts into nano-optical circuits the cost of
recapitulating it would be out of the range of most experimenters ( ie
the base is 3/8 inch ground plate, the ways are Thomson linear ball
bearing slides and the controller is a Philips LPC2138 programmed in
Pygmy Forth ).

While I will happily buy a digital camera and post pictures of my
system, I wonder if there would be more interest in a system built
from the "ground up" out of:

1) Channel and angle iron available from "Home
Despot" ( or the like! );

2) Teflon linear bearing and air hardening
drill rod for ways, acme threaded rod and nuts ( from Enco );

3) A3967SLB stepper drivers ( Newark online
)

4) ( most of all! ) An old Pentium or 486
running EMC or the like for a controller.

Such a system would cost under $100 US and not need a lathe or mill to
construct.

I eagerly await your comments.

Curt

Re: [Homebrew_PCBs] PCB EDM -- further thoughts

2005-07-06 by Alexandre Guimaraes

Hi, Curt

> While I will happily buy a digital camera and post pictures of my
> system, I wonder if there would be more interest in a system built
> from the "ground up" out of:

Please send specially detailed pictures of your "cutting head". The XY
stage is much easier to figure out. The novelty of your technique is the way
you arranged the "head" to work and make clean cuts on the copper.. Very
nice idea, by the way...

Best regards,
Alexandre Guimaraes

Re: PCB EDM -- further thoughts

2005-07-06 by milkgonefunky

--- In Homebrew_PCBs@yahoogroups.com, "curt_rxr" <cwrxr@e...> wrote:
Show quoted textHide quoted text
> Hi All,
>
> Stefan and Bengt were interested in my attempts to configure an EDM
> PCB milling machine. Since my machine was built using surplus from my
> lab's research efforts into nano-optical circuits the cost of
> recapitulating it would be out of the range of most experimenters ( ie
> the base is 3/8 inch ground plate, the ways are Thomson linear ball
> bearing slides and the controller is a Philips LPC2138 programmed in
> Pygmy Forth ).
>
> While I will happily buy a digital camera and post pictures of my
> system, I wonder if there would be more interest in a system built
> from the "ground up" out of:
>
> 1) Channel and angle iron available from "Home
> Despot" ( or the like! );
>
> 2) Teflon linear bearing and air hardening
> drill rod for ways, acme threaded rod and nuts ( from Enco );
>
> 3) A3967SLB stepper drivers ( Newark online
> )
>
> 4) ( most of all! ) An old Pentium or 486
> running EMC or the like for a controller.
>
> Such a system would cost under $100 US and not need a lathe or mill to
> construct.
>
> I eagerly await your comments.
>
> Curt

This is the sort of stuff I was hoping to get into when joining this
YGroup! I am very very interested.

I have an NSK product guide as I was looking at their linear ball
bearing slides. I never knew how much they cost. Are those kind of
products affordable at all or are they super expensive? How much
difference do you think they would make on the quality of the finished
product? I know that they have pretensioning mechanisms to get rid of
backlash which seems as if it would make some large differences but
since I have never done anything like that I wouldn't know :)

If we are using an old 486, should try out RTLinux and write some
basic custom software. I do lots of software development and can help
out in this department.

-Mikey

Re: [Homebrew_PCBs] PCB EDM -- further thoughts

2005-07-07 by Bill Maxwell

Yes Curt, definite interest even though I would need to Australianise the
design for local materials.
Bill

----- Original Message -----
Show quoted textHide quoted text
From: "curt_rxr" <cwrxr@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, July 07, 2005 8:52 AM
Subject: [Homebrew_PCBs] PCB EDM -- further thoughts


> Hi All,
>
> Stefan and Bengt were interested in my attempts to configure an EDM
> PCB milling machine. Since my machine was built using surplus from my
> lab's research efforts into nano-optical circuits the cost of
> recapitulating it would be out of the range of most experimenters ( ie
> the base is 3/8 inch ground plate, the ways are Thomson linear ball
> bearing slides and the controller is a Philips LPC2138 programmed in
> Pygmy Forth ).
>
> While I will happily buy a digital camera and post pictures of my
> system, I wonder if there would be more interest in a system built
> from the "ground up" out of:
>
> 1) Channel and angle iron available from "Home
> Despot" ( or the like! );
>
> 2) Teflon linear bearing and air hardening
> drill rod for ways, acme threaded rod and nuts ( from Enco );
>
> 3) A3967SLB stepper drivers ( Newark online
> )
>
> 4) ( most of all! ) An old Pentium or 486
> running EMC or the like for a controller.
>
> Such a system would cost under $100 US and not need a lathe or mill to
> construct.
>
> I eagerly await your comments.
>
> Curt
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> Yahoo! Groups Links
>
>
>
>
>
>

Re: PCB EDM -- further thoughts

2005-07-07 by Phil

I've been watching this with interest. For me the biggest questions
are
a) cutting electrode design (shape, material, ...)
b) spark control
c) power supply

cnc stuff is well documented on multiple forums but there seems to be
little info on the above issues. I sure hope a simpler power supply
design exists than the one on Garden of EDM.

Please post what ever info you have.

Thanks,
Phil

Re: [Homebrew_PCBs] Re: PCB EDM -- further thoughts

2005-07-07 by Stefan Trethan

On Thu, 07 Jul 2005 05:22:31 +0200, Phil <phil1960us@...> wrote:

Show quoted textHide quoted text
> I've been watching this with interest. For me the biggest questions
> are
> a) cutting electrode design (shape, material, ...)
> b) spark control
> c) power supply
> cnc stuff is well documented on multiple forums but there seems to be
> little info on the above issues. I sure hope a simpler power supply
> design exists than the one on Garden of EDM.
> Please post what ever info you have.
> Thanks,
> Phil


I agree.
While your (Curt) ideas on CNC in general are very interesting, whatever
you know on EDM is unique and much more interesting.

Especially:

What operating parameters do you use or cutting (voltage, current).
Do you use the "boost" function of the eden EDM at all?

How much water is in the tray when cutting?
Do you need to replace that water during cutting?

What angle has your electrode? is it carbon or graphite?

I would most appreciate photos of a cut board, maybe you can put it in a
scanner somewhere and avoid the expense of buying a camera. (Though i
recently bought one and it is a neat toy.)


ST

Re: [Homebrew_PCBs] Re: PCB EDM -- further thoughts

2005-07-07 by Stefan Trethan

On Thu, 07 Jul 2005 08:46:28 +0200, Stefan Trethan <stefan_trethan@...>
wrote:

Show quoted textHide quoted text
>
> What angle has your electrode? is it carbon or graphite?


Also, you said you'll try carbide drills as electrodes - i wonder where to
find information which electrode shows the least wear. Tungsten rods fo
TIG welding might be another option, if it is better than graphite (which
i don't think).
I think the industry uses graphite for sinkers and "soft" metals for other
machines like wirecutters, no?

ST

Re: PCB EDM -- further thoughts

2005-07-07 by lcdpublishing

Hi Curt,

Thanks for taking the time to figure out what we need and are looking
for. As other have mentioned, the CNC mechanicals and such are pretty
easily done and well documented all over the place. If it looks like
fun for you to do, go for it, after all you should have some fun with
this too!


I am really interested in the EDM specifics. Power supply, current
regulation, voltage requirements, flushing, filtering of the water,
type of water required, Electrode material, etc.

Most commercial EDMs that I am familiar with have CNC controls
designed specifically for EDM. They are also adaptive controls
wherein they automaticaly adjust the "Feed rate" during the actual
cutting process. I think this could be a bit of a problem with some
of the current software for CNC available to hobbiests, but, as with
all things, creativity can overcome this.

Chris

Re: PCB EDM -- further thoughts ( slightly OT )

2005-07-07 by curt_rxr

--- In Homebrew_PCBs@yahoogroups.com, "curt_rxr" <cwrxr@e...> wrote:


Show quoted textHide quoted text
> While I will happily buy a digital camera and post pictures of my
> system,

Hi All,

I tried to take a pic of my LPC2138 dip header board with my PHD (
Push Here Dummy ) film camera. It is uploaded into the Photos section
in the PCB EDM folder and is labeled Oops! You can tell why!!!

Any advice as to digital cameras for this sort of work? What sort
optics are needed for closeups? Is digital "zoom" worth while?

Help!

Curt

Re: PCB EDM -- further thoughts ( slightly OT )

2005-07-07 by lcdpublishing

Hi Curt,

I am guessing the photo is simply out of focus. I suspect you had the
camera pretty darn close to the chip when you took the picture. Many
basic cameras don't have a macro mode for taking super close-ups.

Generally, if you set your camera to it's highest resolution, then
take the photo as close as you can and yet still focus, you should get
a pretty good image. If the resolution is high, then we can zoom in
on the image using a viewing program or paint program. As you
suspect, the amount of zoom we can do is pretty limitted, but high
resolution helps a lot.




Show quoted textHide quoted text
> Any advice as to digital cameras for this sort of work? What sort
> optics are needed for closeups? Is digital "zoom" worth while?
>
> Help!
>
> Curt

Re: [Homebrew_PCBs] Re: PCB EDM -- further thoughts ( slightly OT )

2005-07-07 by Leon Heller

----- Original Message -----
From: "curt_rxr" <cwrxr@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, July 07, 2005 5:43 PM
Subject: [Homebrew_PCBs] Re: PCB EDM -- further thoughts ( slightly OT )


> --- In Homebrew_PCBs@yahoogroups.com, "curt_rxr" <cwrxr@e...> wrote:
>
>
>> While I will happily buy a digital camera and post pictures of my
>> system,
>
> Hi All,
>
> I tried to take a pic of my LPC2138 dip header board with my PHD (
> Push Here Dummy ) film camera. It is uploaded into the Photos section
> in the PCB EDM folder and is labeled Oops! You can tell why!!!
>
> Any advice as to digital cameras for this sort of work? What sort
> optics are needed for closeups? Is digital "zoom" worth while?

I get very good results with a Fuji FinePix 2400Zoom camera. It's no longer
made, but you should be able to find something similar. It has a macro
setting which I use for photographing PCBs.

Here is a typical photo taken with it:

http://www.geocities.com/leon_heller/pic.html

I've got lots more on my web site.

Leon
--
Leon Heller, G1HSM
leon.heller@...
http://www.geocities.com/leon_heller


---
[This E-mail has been scanned for viruses but it is your responsibility
to maintain up to date anti virus software on the device that you are
currently using to read this email. ]

Re: [Homebrew_PCBs] Re: PCB EDM -- further thoughts ( slightly OT )

2005-07-07 by Stefan Trethan

On Thu, 07 Jul 2005 18:43:49 +0200, curt_rxr <cwrxr@...> wrote:

Show quoted textHide quoted text
> Hi All,
> I tried to take a pic of my LPC2138 dip header board with my PHD (
> Push Here Dummy ) film camera. It is uploaded into the Photos section
> in the PCB EDM folder and is labeled Oops! You can tell why!!!
> Any advice as to digital cameras for this sort of work? What sort
> optics are needed for closeups? Is digital "zoom" worth while?
> Help!
> Curt


You would want a camera with macro mode.
When i bought mine i made the mistake to first buy a very small camera
with mechanic fault, assuming i can fix it. Didn't work out. Then i bought
a minolta dimage S304, which is much larger, and i'm happy with it. It
isn't cutting edge but it does all i need pretty well. the AF on macro is
a bit bad though but manual is ok for that.
If you don't really need a small camera there are many advantages of
larger cameras, the mechanics for the lens are much more sturdy and they
can use AA NiMHs and not some special rechargeable. Also, you can actually
hold them better.

You don't need much in terms of resolution when the optics are ok, 3MP
should be more than you wish to upload anywhere. Those cameras can be
bought secondhand for a reasonable price from people that always want to
have the latest model.
I looked for optical zoom, often you will not get macro mode without
optical zoom anyway. i don't use the digital zoom.

Many cameras have auto mode (which allows dummies to press the button) and
a manual mode where you can set all the stuff you don't even want to know
about.

There are good reviews on the web which often also show the macro
performance, so always read reviews before you buy.


I found for small stuff my scanner works very good too. The picture is
sharp to over a centimeter above the glass. So for PCBs (even populated)
it is often ok.

ST

Re: [Homebrew_PCBs] Re: PCB EDM -- further thoughts ( slightly OT )

2005-07-07 by Dave Hylands

Hi Curt,

> Any advice as to digital cameras for this sort of work? What sort
> optics are needed for closeups? Is digital "zoom" worth while?

As far as I'm concerned, digital zoom is pretty much a useless feature
used for marketing purposes.

The feature that you're looking for is typically "macro mode", and
often involves manually focusing the camera. I have a PowerShot A95
that also allows external lenses to be attached. This helps quite a
bit for closeup shots.

For example:
http://www.davehylands.com/Machinist/CNC-Spindle-Encoder/Small/03-Closeup.html

and the full sized picture:
http://www.davehylands.com/Machinist/CNC-Spindle-Encoder/03-Closeup.html

I got my 37mm lenses and adapter from: http://www.lensmateonline.com/
(no affiliation)

--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/

Re: PCB EDM -- further thoughts

2005-07-07 by Bengt Sjölund

Hi Curt,

Among others I´m interested in the EDM part mainly as the CNC machine
part is well described on the web.


I say like Phil in message# 9733
I've been watching this with interest. For me the biggest questions are
a) cutting electrode design (shape, material, ...)
b) spark control
c) power supply

I hope you can share your findings, please keep up the good work.

Cheers
Bengt



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

Re: PCB EDM -- further thoughts ( slightly OT )

2005-07-07 by Phil

digital zoom is worthless. ignore it completely in the specs.

Look for macro mode for close up pictures. most digicams have it.
You don't need a lot of megapixels. even 3 would be ok. Make sure
you get a cam with a removable memory card. Most standards are ok but
the cheap cams often come with a tiny card. I'd skip sony since they
push their memory stick, but that's just my opinion.

I use a nikon coolpix 4300 and it sucks. ok, it basically works but I
wish I had my old canon s100. I much prefer canons in general and, as
I said above, don't like sonys.

Phil

Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, "curt_rxr" <cwrxr@e...> wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "curt_rxr" <cwrxr@e...> wrote:
>
>
> > While I will happily buy a digital camera and post pictures of my
> > system,
>
> Hi All,
>
> I tried to take a pic of my LPC2138 dip header board with my PHD (
> Push Here Dummy ) film camera. It is uploaded into the Photos section
> in the PCB EDM folder and is labeled Oops! You can tell why!!!
>
> Any advice as to digital cameras for this sort of work? What sort
> optics are needed for closeups? Is digital "zoom" worth while?
>
> Help!
>
> Curt

Re: [Homebrew_PCBs] Re: PCB EDM -- further thoughts

2005-07-07 by Roy J. Tellason

On Thursday 07 July 2005 03:47 pm, Bengt Sjölund wrote:

Show quoted textHide quoted text
> I say like Phil in message# 9733

I just want to point out that some of us get this list as emails, rather than
as accessing it on the web, and that a reference like that has no meaning
whatsoever for us...

Perhaps quoting a bit of the message you refer to would make your point?

Re: PCB EDM -- further thoughts ( slightly OT )

2005-07-08 by javaguy11111

If you have a cheap webcam like I do, you can break the focus stop and
adjust the focus in alot closer than normal. Would not recommend for
expensive cameras though.


Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
> digital zoom is worthless. ignore it completely in the specs.
>
> Look for macro mode for close up pictures. most digicams have it.
> You don't need a lot of megapixels. even 3 would be ok. Make sure
> you get a cam with a removable memory card. Most standards are ok but
> the cheap cams often come with a tiny card. I'd skip sony since they
> push their memory stick, but that's just my opinion.
>
> I use a nikon coolpix 4300 and it sucks. ok, it basically works but I
> wish I had my old canon s100. I much prefer canons in general and, as
> I said above, don't like sonys.
>
> Phil
>
> --- In Homebrew_PCBs@yahoogroups.com, "curt_rxr" <cwrxr@e...> wrote:
> > --- In Homebrew_PCBs@yahoogroups.com, "curt_rxr" <cwrxr@e...> wrote:
> >
> >
> > > While I will happily buy a digital camera and post pictures of my
> > > system,
> >
> > Hi All,
> >
> > I tried to take a pic of my LPC2138 dip header board with my PHD (
> > Push Here Dummy ) film camera. It is uploaded into the Photos section
> > in the PCB EDM folder and is labeled Oops! You can tell why!!!
> >
> > Any advice as to digital cameras for this sort of work? What sort
> > optics are needed for closeups? Is digital "zoom" worth while?
> >
> > Help!
> >
> > Curt

PCB EDM -- further thoughts

2005-07-25 by curt_rxr

Hi All,

While I'm working on my new setup ( one piece bed and tank made of
plate glass with roller blade bearings, Garden of EDM power supply
with a PIC instead of 7555, steppers controlled with A3967SLBs and
software in Forth on a 486 or Pentium class machine ) you may find the
following books of use:


******************************************************************8

Subject: EDM Sinker Plans for sale

Hi Guys just wanted to let you know that I just finished writing a 170
page book on how to build a small EDM machine.

The machine was first shown at the CNC workshop held in Galesburg Il.
in June of 2005. Photos and a brief description are given on the
following website along with other info on the workshop.

http://neme-s.org/CNC_Workshop/CNC_Workshop_1.htm

I have no connection with NAMES or the website but I think it is a
fair review.

I can supply additional photos of the machine as well as photos of
actual burns.

The book is a home builders How-To Book. It covers
EDM theory
How to build the powersupply,
How to build a very simple servo drive system, (non stepper motor)
How to build a simple precision (ram) slide
How to build a complete dielectric tank with filtering system.
The tank is capable of holding 6+ gallons of dielectric.
The work plate (12"x15")large enough to do serious EDM work.
The system is scaleable should you want a more powerful unit.
A complete section is devoted to electrodes and flushing methods and
techniques need for succesful EDM work.

If interested contact me at

bnf@...

The book sell for $20 USDollars plus $3 for shipping in the U.S.
I accept PayPal and Money orders.

Ben Fleming
1734 N. Viewpoint Dr.
Fayetteville Ar. 72701

For shipping outside of the U.S. please email.


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

Although the plans are for a "sinker" the info should be immediately
useful for anyone looking at "burning" PCBs.



Also of use might be "S-EDM for the Home Shop" published by Practice
Publications, which includes software in Basic on a CD. Although the
plans are only for a relaxation type power supply the drawings of the
machine base are detailed and worth the price alone.

I'll be publishing pictures and plans of my system when it's "ready
for primetime", but at the moment I'm working on my "new" 1954 1 ton
Willys Jeep pickup. It seems that the town thinks that unlicensed
vehicles on private property for more than 30 days are a threat to
western civilization!!!!

Anyway, for the next few weeks I'm going to focused on hammer welding
more than solder...

Curt

Re: [Homebrew_PCBs] Re: PCB EDM -- further thoughts ( slightly OT )

2005-10-20 by lists

In article <dajm45+cqcf@...>,
curt_rxr <cwrxr@...> wrote:
Show quoted textHide quoted text
> I tried to take a pic of my LPC2138 dip header board with my PHD (
> Push Here Dummy ) film camera. It is uploaded into the Photos section
> in the PCB EDM folder and is labeled Oops! You can tell why!!!

> Any advice as to digital cameras for this sort of work? What sort
> optics are needed for closeups? Is digital "zoom" worth while?

In "the old days" with simple film cameras you used to be able to buy a
"close up lens". This was an auxilliary lens that pushed on over the
existing lens and allowed the camera to focus much closer.

They were normally rated in "dioptres" which is an alternative way of
expressing the focal length of the lens.

IIRC 1 dioptre is a focal length of 1m and if the camera was focused to
infinity the effect was to produce focus at 1m, so as you focussed the
lens closer the focal point moved closer still.

The higher the dioptre number the shorter the focal length and the closer
you could get.

You can probably still get them and they will be useable with film or
digital cameras as long as you can get them the right size and have
something to push them onto.

Only a couple of years ago I bought one in a standard filter holder (58mm
screw thread) and can stick it on the front of my SLR.

Ultimately though, for close up work, you really need an SLR and with
everyone going digital, quite good quality film SLRs can be had quite
cheaply. Extension tubes and bellows can then allow image sizes on your
film or sensor which are larger than the original object.

Stuart

Re: PCB EDM -- further thoughts ( slightly OT )

2005-10-21 by mikegw20

--- In Homebrew_PCBs@yahoogroups.com, lists <stuart.winsor.lists@d...>
wrote:
>
> In article <dajm45+cqcf@e...>,
> curt_rxr <cwrxr@e...> wrote:
> > I tried to take a pic of my LPC2138 dip header board with my PHD (
> > Push Here Dummy ) film camera. It is uploaded into the Photos
section
Show quoted textHide quoted text
> > in the PCB EDM folder and is labeled Oops! You can tell why!!!
>
> > Any advice as to digital cameras for this sort of work? What sort
> > optics are needed for closeups? Is digital "zoom" worth while?
>

How about using a flat-bed scanner? True it is more cumbersome for
bigger stuff, but it would be hard to beat the resolution.

Mike

Re: [Homebrew_PCBs] Re: PCB EDM -- further thoughts ( slightly OT )

2005-10-21 by Stefan Trethan

On Fri, 21 Oct 2005 06:31:00 +0200, mikegw20 <mikegw20@...> wrote:

Show quoted textHide quoted text
>
> How about using a flat-bed scanner? True it is more cumbersome for
> bigger stuff, but it would be hard to beat the resolution.
> Mike


and many have sufficient in-depth focus for populated circuit boards (mine
about 15mm).
Much better at small stuff than the camera.

Mine has such a thread for lenses, but i dunno if i'll ever want to afford
one. It's smaller than the standard filter thread.

ST