Homebrew_PCBs

I was wanting to make sure that everything lined up on both sides of a board -- easily. I thought a solution would be to make a registration hole punch. I know the pro ones have cameras looking down the bore of the hole punch, but I wasn't exactly sure where to begin making a diy version of that.

I was thinking a solenoid with some sort of hole puncher, but I wouldn't know where to get precise equipment for the puncher itself.

Any ideas?

> crazy_geekchick wrote:
>
> I was wanting to make sure that everything
> lined up on both sides of a board -- easily.
> I thought a solution would be to make a
> registration hole punch. I know the pro ones
> have cameras looking down the bore of the
> hole punch, but I wasn't exactly sure where
> to begin making a diy version of that.
>
> I was thinking a solenoid with some sort of
> hole puncher, but I wouldn't know where to
> get precise equipment for the puncher itself.
>
> Any ideas?

One I have seen actually had a loupe/lens with
a sight on it that looked down the bore.

When you lined it up, you pulled out the lens
and replaced it with a metal punch part.

Doesn't look like too hard an idea to make.

The replacement of the lens with the punch is a good idea.

I was worried about precision between the hole and the registration pin.

Do you have any idea where to get the hole puncher and a matching hole to punch into?

Most of the stuff I have found was like metal punches.

--- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@...> wrote:
>
>
>
> > crazy_geekchick wrote:
> >
> > I was wanting to make sure that everything
> > lined up on both sides of a board -- easily.
> > I thought a solution would be to make a
> > registration hole punch. I know the pro ones
> > have cameras looking down the bore of the
> > hole punch, but I wasn't exactly sure where
> > to begin making a diy version of that.
> >
> > I was thinking a solenoid with some sort of
> > hole puncher, but I wouldn't know where to
> > get precise equipment for the puncher itself.
> >
> > Any ideas?
>
> One I have seen actually had a loupe/lens with
> a sight on it that looked down the bore.
>
> When you lined it up, you pulled out the lens
> and replaced it with a metal punch part.
>
> Doesn't look like too hard an idea to make.
>

Although the punch would / will work why make it more complicated?
Seems to me their are many ways to accomplish this an most go with what works for them.
One suggestion would be to add 2 additional holes to your board (or use 2 existing ones)
drill them first....(these are the registration holes) I lean towards having them some know distance apart and location.
ie .25 from the bottom edge and 1.0" inch apart and offset from one of the edges.. this what when I flip the board I already know
what side I using even before any transfer has occurred.

use the hole to line up your stencil/template/transfer etc....
do the photo/etch one at a time or both side at once. what ever works for you.
I do mine both side at one time. once completed I then commence drilling the balance of the holes.

S

On Jul 30, 2013, at 7:52 PM, "crazy_geekchick" <amiegrl2001@...> wrote:

> The replacement of the lens with the punch is a good idea.
>
> I was worried about precision between the hole and the registration pin.
>
> Do you have any idea where to get the hole puncher and a matching hole to punch into?
>
> Most of the stuff I have found was like metal punches.
>
> --- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@...> wrote:
> >
> >
> >
> > > crazy_geekchick wrote:
> > >
> > > I was wanting to make sure that everything
> > > lined up on both sides of a board -- easily.
> > > I thought a solution would be to make a
> > > registration hole punch. I know the pro ones
> > > have cameras looking down the bore of the
> > > hole punch, but I wasn't exactly sure where
> > > to begin making a diy version of that.
> > >
> > > I was thinking a solenoid with some sort of
> > > hole puncher, but I wouldn't know where to
> > > get precise equipment for the puncher itself.
> > >
> > > Any ideas?
> >
> > One I have seen actually had a loupe/lens with
> > a sight on it that looked down the bore.
> >
> > When you lined it up, you pulled out the lens
> > and replaced it with a metal punch part.
> >
> > Doesn't look like too hard an idea to make.
> >
>
>



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

> Although the punch would / will work why make it
> more complicated?
> <SNIP>
> One suggestion would be to add 2 additional holes
> to your board (or use 2 existing ones)drill them
> first....(these are the registration holes)
> <SNIP>

The point behind a punch is that you want to easily
line up the artwork with the registrations pins on
a jig. Your PCB is taken as already being pre-
drilled (by CNC) to also fit those registration
pins.

If your in the business of hand drilling I agree
that the punch isn't needed.

I purchased one of those from Grizzley Tools. Look
here: http://www.grizzly.com/products/Optical-Punch-Set/H5781

Charlie

On Tue, 30 Jul 2013 23:52:50 -0000 "crazy_geekchick"
<amiegrl2001@...> writes:

The replacement of the lens with the punch is a good idea.

I was worried about precision between the hole and the registration pin.

Do you have any idea where to get the hole puncher and a matching hole to
punch into?

Most of the stuff I have found was like metal punches.

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

>
>
>
> > crazy_geekchick wrote:
> >
> > I was wanting to make sure that everything
> > lined up on both sides of a board -- easily.
> > I thought a solution would be to make a
> > registration hole punch. I know the pro ones
> > have cameras looking down the bore of the
> > hole punch, but I wasn't exactly sure where
> > to begin making a diy version of that.
> >
> > I was thinking a solenoid with some sort of
> > hole puncher, but I wouldn't know where to
> > get precise equipment for the puncher itself.
> >
> > Any ideas?
>
> One I have seen actually had a loupe/lens with
> a sight on it that looked down the bore.
>
> When you lined it up, you pulled out the lens
> and replaced it with a metal punch part.
>
> Doesn't look like too hard an idea to make.
>

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

> Charlie wrote:
>
> I purchased one of those from Grizzley Tools.
> Look here:
> http://www.grizzly.com/products/Optical-Punch-Set/H5781

Thanks Charlie,

That looks the part for the lens (The hard part).

Just need to replace the marking punch with a
hole punch and probably a through bore on the
holder. Or maybe a complete replacement holder &
punch.

About the grizzley tool...
In case anyone is wondering how the tool works.
The sights are the plastic cylinders
with precise cross-hairs at the bottom. The cylinder
gathers a surprising amount of light on the top portion
(the part that sticks out of the black aluminum holder)
and effectively illuminates the cross-hairs and what
you want to mark. When everything is lined up, you
hold the holder in place, then pull out the plastic
cyclinder and replace it with the metal center punch
and give it just a "tap" with a small hammer. That will mark
the exact spot where you want to drill, punch or whatever.
There's a piece of rubber on the bottom of the aluminum
holder to keep it from slipping while you're doing the marking.

Charlie

On Wed, 31 Jul 2013 03:49:16 -0000 "cunningfellow"
<andrewm1973@...> writes:

> Charlie wrote:
>
> I purchased one of those from Grizzley Tools.
> Look here:
> http://www.grizzly.com/products/Optical-Punch-Set/H5781

Thanks Charlie,

That looks the part for the lens (The hard part).

Just need to replace the marking punch with a
hole punch and probably a through bore on the
holder. Or maybe a complete replacement holder &
punch.




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

Drilling holes is a fine idea, but how does that put holes in the artwork to line it all up? That is the part I am worried about.

Putting pins through the artwork allows them to be lined up precisely front to back. Putting it through the board may standardize that across boards, but it the hole in the board alone wouldn't seem to line up the artwork to me?

Am I missing something?

The reason I was concerned about accurate registration hole size (in the artwork) was to avoid any misalignment there too, especially for anything with a fine pitch.

--- In Homebrew_PCBs@yahoogroups.com, Sam Rod <mail4sam@...> wrote:
>
> Although the punch would / will work why make it more complicated?
> Seems to me their are many ways to accomplish this an most go with what works for them.
> One suggestion would be to add 2 additional holes to your board (or use 2 existing ones)
> drill them first....(these are the registration holes) I lean towards having them some know distance apart and location.
> ie .25 from the bottom edge and 1.0" inch apart and offset from one of the edges.. this what when I flip the board I already know
> what side I using even before any transfer has occurred.
>
> use the hole to line up your stencil/template/transfer etc....
> do the photo/etch one at a time or both side at once. what ever works for you.
> I do mine both side at one time. once completed I then commence drilling the balance of the holes.
>
> S
>
>
>
> On Jul 30, 2013, at 7:52 PM, "crazy_geekchick" <amiegrl2001@...> wrote:
>
> > The replacement of the lens with the punch is a good idea.
> >
> > I was worried about precision between the hole and the registration pin.
> >
> > Do you have any idea where to get the hole puncher and a matching hole to punch into?
> >
> > Most of the stuff I have found was like metal punches.
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@> wrote:
> > >
> > >
> > >
> > > > crazy_geekchick wrote:
> > > >
> > > > I was wanting to make sure that everything
> > > > lined up on both sides of a board -- easily.
> > > > I thought a solution would be to make a
> > > > registration hole punch. I know the pro ones
> > > > have cameras looking down the bore of the
> > > > hole punch, but I wasn't exactly sure where
> > > > to begin making a diy version of that.
> > > >
> > > > I was thinking a solenoid with some sort of
> > > > hole puncher, but I wouldn't know where to
> > > > get precise equipment for the puncher itself.
> > > >
> > > > Any ideas?
> > >
> > > One I have seen actually had a loupe/lens with
> > > a sight on it that looked down the bore.
> > >
> > > When you lined it up, you pulled out the lens
> > > and replaced it with a metal punch part.
> > >
> > > Doesn't look like too hard an idea to make.
> > >
> >
> >
>
>
>
> [Non-text portions of this message have been removed]
>

On some of my projects I place a 1/16 to 1/18 holes in/on my artwork.
thats what I use to line up to the holes.
Sometimes I use the mounting holes too. doesnt matter what hole you use as long as you know which ones they are
Minimum of 2 spaced as far apart as possible for best accuracy.

On Jul 31, 2013, at 5:41 PM, "crazy_geekchick" <amiegrl2001@...> wrote:

> Drilling holes is a fine idea, but how does that put holes in the artwork to line it all up? That is the part I am worried about.
>
> Putting pins through the artwork allows them to be lined up precisely front to back. Putting it through the board may standardize that across boards, but it the hole in the board alone wouldn't seem to line up the artwork to me?
>
> Am I missing something?
>
> The reason I was concerned about accurate registration hole size (in the artwork) was to avoid any misalignment there too, especially for anything with a fine pitch.
>
> --- In Homebrew_PCBs@yahoogroups.com, Sam Rod <mail4sam@...> wrote:
> >
> > Although the punch would / will work why make it more complicated?
> > Seems to me their are many ways to accomplish this an most go with what works for them.
> > One suggestion would be to add 2 additional holes to your board (or use 2 existing ones)
> > drill them first....(these are the registration holes) I lean towards having them some know distance apart and location.
> > ie .25 from the bottom edge and 1.0" inch apart and offset from one of the edges.. this what when I flip the board I already know
> > what side I using even before any transfer has occurred.
> >
> > use the hole to line up your stencil/template/transfer etc....
> > do the photo/etch one at a time or both side at once. what ever works for you.
> > I do mine both side at one time. once completed I then commence drilling the balance of the holes.
> >
> > S
> >
> >
> >
> > On Jul 30, 2013, at 7:52 PM, "crazy_geekchick" <amiegrl2001@...> wrote:
> >
> > > The replacement of the lens with the punch is a good idea.
> > >
> > > I was worried about precision between the hole and the registration pin.
> > >
> > > Do you have any idea where to get the hole puncher and a matching hole to punch into?
> > >
> > > Most of the stuff I have found was like metal punches.
> > >
> > > --- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@> wrote:
> > > >
> > > >
> > > >
> > > > > crazy_geekchick wrote:
> > > > >
> > > > > I was wanting to make sure that everything
> > > > > lined up on both sides of a board -- easily.
> > > > > I thought a solution would be to make a
> > > > > registration hole punch. I know the pro ones
> > > > > have cameras looking down the bore of the
> > > > > hole punch, but I wasn't exactly sure where
> > > > > to begin making a diy version of that.
> > > > >
> > > > > I was thinking a solenoid with some sort of
> > > > > hole puncher, but I wouldn't know where to
> > > > > get precise equipment for the puncher itself.
> > > > >
> > > > > Any ideas?
> > > >
> > > > One I have seen actually had a loupe/lens with
> > > > a sight on it that looked down the bore.
> > > >
> > > > When you lined it up, you pulled out the lens
> > > > and replaced it with a metal punch part.
> > > >
> > > > Doesn't look like too hard an idea to make.
> > > >
> > >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>



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

I think I need to order one of these tools and put it in the toolchest next to my drill press.

73
Jim N6OTQ

>________________________________
> From: "n0tt1@..." <n0tt1@...>
>To: Homebrew_PCBs@yahoogroups.com
>Sent: Wednesday, July 31, 2013 9:20 AM
>Subject: Re: [Homebrew_PCBs] Re: Has anyone made a diy registration hole punch or add pins to diy exposure kit?
>
>
>About the grizzley tool...
>In case anyone is wondering how the tool works.
>The sights are the plastic cylinders
>with precise cross-hairs at the bottom.  The cylinder
>gathers a surprising amount of light on the top portion
>(the part that sticks out of the black aluminum holder)
>and effectively illuminates the cross-hairs and what
>you want to mark.  When everything is lined up, you
>hold the holder in place, then pull out the plastic
>cyclinder and replace it with the metal center punch
>and give it just a "tap" with a small hammer.  That will mark
>the exact spot where you want to drill, punch or whatever.
>There's a piece of rubber on the bottom of the aluminum
>holder to keep it from slipping while you're doing the marking.
>
>Charlie
>
>On Wed, 31 Jul 2013 03:49:16 -0000 "cunningfellow"
><andrewm1973@...> writes:
> 
>
>> Charlie wrote:
>>
>> I purchased one of those from Grizzley Tools.
>> Look here:
>> http://www.grizzly.com/products/Optical-Punch-Set/H5781
>

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

________________________________

When I used the photosensitive method, I did the alignment holes the following way:

I used tacks.  So drilling holes in the PCB is the easy part.  Instead of driling holes in the plastic film, I used the tack to punch the holein the artwork.  I may have used aheated drill bit, can't remember.

I did some punches into labeling before and I used a biopsy punch.  Nice and sharp.

From: crazy_geekchick <amiegrl2001@...>
To: Homebrew_PCBs@yahoogroups.com
Sent: Wednesday, July 31, 2013 5:41 PM
Subject: [Homebrew_PCBs] Re: Has anyone made a diy registration hole punch or add pins to diy exposure kit?



 
Drilling holes is a fine idea, but how does that put holes in the artwork to line it all up? That is the part I am worried about.

Putting pins through the artwork allows them to be lined up precisely front to back. Putting it through the board may standardize that across boards, but it the hole in the board alone wouldn't seem to line up the artwork to me?

Am I missing something?


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

Switch to: Text-Only, Daily Digest • Unsubscribe • Terms of Use • Send us Feedback
.



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

For those who reside in Canada, here's an optical punch available from Lee Valley:

http://www.leevalley.com/en/wood/page.aspx?p=45502&cat=1,180,42311

Jim

--- In Homebrew_PCBs@yahoogroups.com, <n0tt1@...> wrote:
>
> About the grizzley tool...
> In case anyone is wondering how the tool works.
> The sights are the plastic cylinders
> with precise cross-hairs at the bottom. The cylinder
> gathers a surprising amount of light on the top portion
> (the part that sticks out of the black aluminum holder)
> and effectively illuminates the cross-hairs and what
> you want to mark. When everything is lined up, you
> hold the holder in place, then pull out the plastic
> cyclinder and replace it with the metal center punch
> and give it just a "tap" with a small hammer. That will mark
> the exact spot where you want to drill, punch or whatever.
> There's a piece of rubber on the bottom of the aluminum
> holder to keep it from slipping while you're doing the marking.
>
> Charlie
>
> On Wed, 31 Jul 2013 03:49:16 -0000 "cunningfellow"
> <andrewm1973@...> writes:
>
>
>
> > Charlie wrote:
> >
> > I purchased one of those from Grizzley Tools.
> > Look here:
> > http://www.grizzly.com/products/Optical-Punch-Set/H5781
>
> Thanks Charlie,
>
> That looks the part for the lens (The hard part).
>
> Just need to replace the marking punch with a
> hole punch and probably a through bore on the
> holder. Or maybe a complete replacement holder &
> punch.
>
>
>
>
> [Non-text portions of this message have been removed]
>

How did you make the holes in the artwork?

--- In Homebrew_PCBs@yahoogroups.com, Sam Rod <mail4sam@...> wrote:
>
> On some of my projects I place a 1/16 to 1/18 holes in/on my artwork.
> thats what I use to line up to the holes.
> Sometimes I use the mounting holes too. doesnt matter what hole you use as long as you know which ones they are
> Minimum of 2 spaced as far apart as possible for best accuracy.
>
>
>
>
>
>
>
> On Jul 31, 2013, at 5:41 PM, "crazy_geekchick" <amiegrl2001@...> wrote:
>
> > Drilling holes is a fine idea, but how does that put holes in the artwork to line it all up? That is the part I am worried about.
> >
> > Putting pins through the artwork allows them to be lined up precisely front to back. Putting it through the board may standardize that across boards, but it the hole in the board alone wouldn't seem to line up the artwork to me?
> >
> > Am I missing something?
> >
> > The reason I was concerned about accurate registration hole size (in the artwork) was to avoid any misalignment there too, especially for anything with a fine pitch.
> >
> > --- In Homebrew_PCBs@yahoogroups.com, Sam Rod <mail4sam@> wrote:
> > >
> > > Although the punch would / will work why make it more complicated?
> > > Seems to me their are many ways to accomplish this an most go with what works for them.
> > > One suggestion would be to add 2 additional holes to your board (or use 2 existing ones)
> > > drill them first....(these are the registration holes) I lean towards having them some know distance apart and location.
> > > ie .25 from the bottom edge and 1.0" inch apart and offset from one of the edges.. this what when I flip the board I already know
> > > what side I using even before any transfer has occurred.
> > >
> > > use the hole to line up your stencil/template/transfer etc....
> > > do the photo/etch one at a time or both side at once. what ever works for you.
> > > I do mine both side at one time. once completed I then commence drilling the balance of the holes.
> > >
> > > S
> > >
> > >
> > >
> > > On Jul 30, 2013, at 7:52 PM, "crazy_geekchick" <amiegrl2001@> wrote:
> > >
> > > > The replacement of the lens with the punch is a good idea.
> > > >
> > > > I was worried about precision between the hole and the registration pin.
> > > >
> > > > Do you have any idea where to get the hole puncher and a matching hole to punch into?
> > > >
> > > > Most of the stuff I have found was like metal punches.
> > > >
> > > > --- In Homebrew_PCBs@yahoogroups.com, "cunningfellow" <andrewm1973@> wrote:
> > > > >
> > > > >
> > > > >
> > > > > > crazy_geekchick wrote:
> > > > > >
> > > > > > I was wanting to make sure that everything
> > > > > > lined up on both sides of a board -- easily.
> > > > > > I thought a solution would be to make a
> > > > > > registration hole punch. I know the pro ones
> > > > > > have cameras looking down the bore of the
> > > > > > hole punch, but I wasn't exactly sure where
> > > > > > to begin making a diy version of that.
> > > > > >
> > > > > > I was thinking a solenoid with some sort of
> > > > > > hole puncher, but I wouldn't know where to
> > > > > > get precise equipment for the puncher itself.
> > > > > >
> > > > > > Any ideas?
> > > > >
> > > > > One I have seen actually had a loupe/lens with
> > > > > a sight on it that looked down the bore.
> > > > >
> > > > > When you lined it up, you pulled out the lens
> > > > > and replaced it with a metal punch part.
> > > > >
> > > > > Doesn't look like too hard an idea to make.
> > > > >
> > > >
> > > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
>
>
>
> [Non-text portions of this message have been removed]
>

I have never heard of the biopsy punch before. Did you go through all the layers of the artwork at once?

I was thinking of using a replacement part for a 3-hole punch that just had the punch, spring, and frame with a hole. I thought I could use a web cam to get the alignment perfect, especially between the different layers (copper/solder mask, front/back).

The tack into the pcb through the artwork sounds interesting.

Thanks btw

--- In Homebrew_PCBs@yahoogroups.com, KeepIt SimpleStupid <keepitsimplestupid@...> wrote:
>
>
>
>
>
> ________________________________
>
> When I used the photosensitive method, I did the alignment holes the following way:
>
> I used tacks.  So drilling holes in the PCB is the easy part.  Instead of driling holes in the plastic film, I used the tack to punch the holein the artwork.  I may have used aheated drill bit, can't remember.
>
> I did some punches into labeling before and I used a biopsy punch.  Nice and sharp.
>
> From: crazy_geekchick <amiegrl2001@...>
> To: Homebrew_PCBs@yahoogroups.com
> Sent: Wednesday, July 31, 2013 5:41 PM
> Subject: [Homebrew_PCBs] Re: Has anyone made a diy registration hole punch or add pins to diy exposure kit?
>
>
>
>  
> Drilling holes is a fine idea, but how does that put holes in the artwork to line it all up? That is the part I am worried about.
>
> Putting pins through the artwork allows them to be lined up precisely front to back. Putting it through the board may standardize that across boards, but it the hole in the board alone wouldn't seem to line up the artwork to me?
>
> Am I missing something?
>
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> Switch to: Text-Only, Daily Digest • Unsubscribe • Terms of Use • Send us Feedback
> .
>
>
>
> [Non-text portions of this message have been removed]
>

As i said, I made a laser printed label for a project and I had to find a way to punch some clean holes and I tried a biopsy punch. e.g. http://www.vetlab.com/Biopunch.htm%c2%a0 Finding them might be tough.   I have used a self-healing cutting mat at one time, e.g. http://www.amazon.com/X-Acto-X7761-Self-healing-cutting-measuring/dp/B0013CKM2A%c2%a0 You need something firm and slightly soft.  The biopsy punch does have an alignment issue, but it does do a really clean hole in a piece of paper/plastic.  I ve not tried this method for aligning, however when I learned to do taped artwork at HP/Agilent in the mid 70's,  posts about 3/16" in diameter were used to line up the artwork sheets.


I may have also did the "punching" by drilling the artwork sandwiched between two pieces of clear acrylic. 

If your really worried about accuracy, of say a scribed line, one can use an optical center punch http://www.wttool.com/index/page/product/product_id/39550/product_name/Optical+Center+Punch+Set+%28WT%29&update_continue_shopping=true

To use an optical center punch, you position a crosshair with the base precisely wher eyou want to mark.  Then you replace the optics with a center punch and mark the hole.  ou would be doing this on a piece of acrylic.

I've ground 5/8" bits in the pilot point shape in 3/8" thick Lexan sheets and used the saop as the lubercant, so the method works.


Once you have your center punch mark, you can use a bit of dishwashing soap and water as a lubercant/cooler for the drill bit.  This method should also make an accurate hole and you also should be able to line up all of the layers of the artwork.

I think I also used the hot pin method at one time to center the mark.


If you do any drilling in sheet stock use a "pilot point" bit.  See a pic here: http://toolguyd.com/a-few-fun-tool-closeup-photos.

Some of the boards, I did I used a UV mask aligner that we happened to have at work, but I just used it for the exposure.
I also had a commercial spin coater available to make a small board.  A hole in the PCB causes some minor issues when spinning on the resist,   Abberations at the holes.   The spin coater basically is a high speed spinning vacuum chuck with ramp-up and ramp-down rates and a way to catch the excess resist.

I'll add that a mix of vinegar and salt will clean copper very well andI used the surface tension of water rather than any sort of exposure frame to keep the artwork in contact with the PCB.  Just place a drop of water between the artwork and the board.

I used ptranslucent olyester paper with the laser printed artwork, but I dont have a source for that now.

I am confident that a surgical biopsy biopsy punch can be used to make a large, precise hole from say 1.5 to 6 mm diameter.  Alighnment may not be precise, but with a hole pattern as large as the punch or say concentric circles, you should be able to align things pretty well.  I remember specific target patterns from Bishop Graphics that were used when layouts were taped.

You might need a jig of some sort to make a precise marks.  i.e a piece of flat brass drilled with a pilot point bit and/or the use of an over/under reamer.

Don't expect a super lifetime using the biopsy punch.


A pilot point bit will drill sheet metal with a round hole and not a triangular shaped thing you would get with a conventional drill bit.  Now, when I had someone drill about two hundred  1/4" holes in a thin sheet of soft Molydynium, I set him up to use a round nose mill.


The web cam probably won't be viable because you can't see depth.  A stereo microscope viewer would be a better technology.  You punch may deform the intended hole.  Paper would be drilled.  I've never used them, but their are drills for paper: http://www.ultimateprintfinishing.com/categories/Parts-and-Supplies/Drill-Accessories/Drill-Bits/%c2%a0


________________________________
From: crazy_geekchick <amiegrl2001@...>
To: Homebrew_PCBs@yahoogroups.com
Sent: Thursday, August 1, 2013 1:07 AM
Subject: [Homebrew_PCBs] Re: Has anyone made a diy registration hole punch or add pins to diy exposure kit?



 
I have never heard of the biopsy punch before. Did you go through all the layers of the artwork at once?

I was thinking of using a replacement part for a 3-hole punch that just had the punch, spring, and frame with a hole. I thought I could use a web cam to get the alignment perfect, especially between the different layers (copper/solder mask, front/back).

The tack into the pcb through the artwork sounds interesting.

Thanks btw



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.



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

With the web cam, I was wanting to make one of those semi-automatic registration artwork punches.

On the artwork you make a round circle of a precise size.

You aim the web cam at a hole of the same size and light it from the other side.

You put the artwork over the hole, and once it completely covers the hole (the webcam goes dark), it is ready to punch.

Opposite the hole and webcam you have an electronic hole punch of that same precise size. When lined up and activated, it punches the hole.

I didn't think depth would be a big deal?

--- In Homebrew_PCBs@yahoogroups.com, KeepIt SimpleStupid <keepitsimplestupid@...> wrote:
>
> As i said, I made a laser printed label for a project and I had to find a way to punch some clean holes and I tried a biopsy punch. e.g. http://www.vetlab.com/Biopunch.htm%c3%82%c2%a0 Finding them might be tough.   I have used a self-healing cutting mat at one time, e.g. http://www.amazon.com/X-Acto-X7761-Self-healing-cutting-measuring/dp/B0013CKM2A%c3%82%c2%a0 You need something firm and slightly soft.  The biopsy punch does have an alignment issue, but it does do a really clean hole in a piece of paper/plastic.  I ve not tried this method for aligning, however when I learned to do taped artwork at HP/Agilent in the mid 70's,  posts about 3/16" in diameter were used to line up the artwork sheets.
>
>
> I may have also did the "punching" by drilling the artwork sandwiched between two pieces of clear acrylic. 
>
> If your really worried about accuracy, of say a scribed line, one can use an optical center punch http://www.wttool.com/index/page/product/product_id/39550/product_name/Optical+Center+Punch+Set+%28WT%29&update_continue_shopping=true
>
> To use an optical center punch, you position a crosshair with the base precisely wher eyou want to mark.  Then you replace the optics with a center punch and mark the hole.  ou would be doing this on a piece of acrylic.
>
> I've ground 5/8" bits in the pilot point shape in 3/8" thick Lexan sheets and used the saop as the lubercant, so the method works.
>
>
> Once you have your center punch mark, you can use a bit of dishwashing soap and water as a lubercant/cooler for the drill bit.  This method should also make an accurate hole and you also should be able to line up all of the layers of the artwork.
>
> I think I also used the hot pin method at one time to center the mark.
>
>
> If you do any drilling in sheet stock use a "pilot point" bit.  See a pic here: http://toolguyd.com/a-few-fun-tool-closeup-photos.
>
> Some of the boards, I did I used a UV mask aligner that we happened to have at work, but I just used it for the exposure.
> I also had a commercial spin coater available to make a small board.  A hole in the PCB causes some minor issues when spinning on the resist,   Abberations at the holes.   The spin coater basically is a high speed spinning vacuum chuck with ramp-up and ramp-down rates and a way to catch the excess resist.
>
> I'll add that a mix of vinegar and salt will clean copper very well andI used the surface tension of water rather than any sort of exposure frame to keep the artwork in contact with the PCB.  Just place a drop of water between the artwork and the board.
>
> I used ptranslucent olyester paper with the laser printed artwork, but I dont have a source for that now.
>
> I am confident that a surgical biopsy biopsy punch can be used to make a large, precise hole from say 1.5 to 6 mm diameter.  Alighnment may not be precise, but with a hole pattern as large as the punch or say concentric circles, you should be able to align things pretty well.  I remember specific target patterns from Bishop Graphics that were used when layouts were taped.
>
> You might need a jig of some sort to make a precise marks.  i.e a piece of flat brass drilled with a pilot point bit and/or the use of an over/under reamer.
>
> Don't expect a super lifetime using the biopsy punch.
>
>
> A pilot point bit will drill sheet metal with a round hole and not a triangular shaped thing you would get with a conventional drill bit.  Now, when I had someone drill about two hundred  1/4" holes in a thin sheet of soft Molydynium, I set him up to use a round nose mill.
>
>
> The web cam probably won't be viable because you can't see depth.  A stereo microscope viewer would be a better technology.  You punch may deform the intended hole.  Paper would be drilled.  I've never used them, but their are drills for paper: http://www.ultimateprintfinishing.com/categories/Parts-and-Supplies/Drill-Accessories/Drill-Bits/%c3%82%c2%a0
>
>
> ________________________________
> From: crazy_geekchick <amiegrl2001@...>
> To: Homebrew_PCBs@yahoogroups.com
> Sent: Thursday, August 1, 2013 1:07 AM
> Subject: [Homebrew_PCBs] Re: Has anyone made a diy registration hole punch or add pins to diy exposure kit?
>
>
>
>  
> I have never heard of the biopsy punch before. Did you go through all the layers of the artwork at once?
>
> I was thinking of using a replacement part for a 3-hole punch that just had the punch, spring, and frame with a hole. I thought I could use a web cam to get the alignment perfect, especially between the different layers (copper/solder mask, front/back).
>
> The tack into the pcb through the artwork sounds interesting.
>
> Thanks btw
>
>
>
> Switch to: Text-Only, Daily Digest • Unsubscribe • Terms of Use • Send us Feedback
> .
>
>
>
> [Non-text portions of this message have been removed]
>

1980s technology:

Back in the day, one of my CBer friends got some plans for a 2-transistor push-pull RF amplifier that used a double-sided PC board.  He had no way to make a 2-sided board with both sides in registration.

So he made two one-sided boards and carefully drilled the four corner holes to mount the board(s) in the chassis, and then stuck them together and drilled the through holes.

It worked.

I was amazed.

However, I was more amazed when one of the RF transistors literally exploded and the amp kept working, but only at half power.


Nowadays you can buy this exact same PCB from a number of vendors, pre-drilled and with thru-plated vias.  Progress .... along with the 21st century invention of "competition" amplifiers that are made by cutting PCB "islands" and glueing them to a substrate, allowing the builder to construct multi-pair amps Manhattan-style / dead-bug style with essentially no need for etching a board.  Only a hacksaw is required, or big tin snips, or a shear brake.

73
Jim N6OTQ

>

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

On Thu, 1 Aug 2013 12:54:55 -0700 (PDT), you wrote:

>1980s technology:
>
>Back in the day, one of my CBer friends got some plans for a 2-transistor push-pull RF amplifier that used a double-sided PC board.  He had no way to make a 2-sided board with both sides in registration.
>
>So he made two one-sided boards and carefully drilled the four corner holes to mount the board(s) in the chassis, and then stuck them together and drilled the through holes.
>
>It worked.
>
>I was amazed.
>
>However, I was more amazed when one of the RF transistors literally exploded and the amp kept working, but only at half power.
>
>
>Nowadays you can buy this exact same PCB from a number of vendors, pre-drilled and with thru-plated vias.  Progress .... along with the 21st century invention of "competition" amplifiers that are made by cutting PCB "islands" and glueing them to a substrate, allowing the builder to construct multi-pair amps Manhattan-style / dead-bug style with essentially no need for etching a board.  Only a hacksaw is required, or big tin snips, or a shear brake.

On the other hand, this is a homebrew PC board group. The argument
for doing boards yourself comes down to money and time. Generally, a
board you do yourself is less expensive than otherwise. Quality may
be an issue, however. A microprocessor/FPGA board, double sided,
about 4.5 by 6 inches, costs either 22 dollars cheapest in China, or
some 65 to 120 dollars made in the good ol' USA. We're talking
delivery time as well.

With printable artwork, and nothing else needs doing, I can have that
board etched, ready to be epoxied together, at the end of the day for
about 3.50 USD for material, not counting the etchant, toner and
epoxy.

24 hours later, the glue has set, and it's stitching top and bottom
together, say half a day doing that, half a day mounting parts (a
slight bit more than needed), and in theory, in 3 days, I have a board
that is done.

China takes a bit longer, and I'd really hate to have sent them a bad
layout without resorting to prototypes first.

However, if I want solder mask, plated through holes, and silk screen,
they get the job.

Harvey

>
>73
>Jim N6OTQ
>
>
>
>>
>
>[Non-text portions of this message have been removed]

I have uploaded two sets of drawings that illustrate my thoughts on this problem in the Photos section of the board.

http://groups.yahoo.com/group/Homebrew_PCBs/photos/album/1427693708/pic/list

The first pair show my method for registering the two sides using alignment pins. The main thought here is that you do not need to use two ROUND holes. Two round holes are overkill for aligning the two sides and it is hard to punch and drill these holes at the same spacing on both the art work and the boards. Any differences in these spacings, even just a couple of thousandths of an inch, will result in problems. It is better to use one round hole and a second OVAL one.

An object in three dimensional space has only six degrees of freedom, the three longitudinal axis, X, Y, and Z and the rotational axis about these three longitudinal ones. The round hole restricts the art work in two dimensions (X and Y) or two degrees of freedom. The oval hole restricts it in a third one (Z rotation). Finally, the exposure frame provides alignment in three more degrees of freedom (Z, X rotation, and Y rotation). That is all that is necessary and any additional constraints can only result in problems if they are not consistent with the first six. A second round hole provides redundant constraint in the Y direction.

Check out the drawings to see the details.

A second pair of drawings shows the exposure frame that I have actually built and used for two sided exposures. They are at the same link as above.

It does not use any pins or holes. Instead, it uses two edges of the film/art work that are at right angles to each other and a pair of alignment straight edges that form a 90 degree corner. You simply push the board and then the film into that corner and close the clear cover over it. For the second side, you flip the board over and change the orientation so that the same corner of the board is in that corner formed by the alignment edges. This provides alignment without any holes or pins. I have used this frame for exposing boards with 0.1" grid spacing and feel it would work with components on a 0.05" grid with a bit of care. All drilling of the board can be done after both sides are etched.

Both of these methods avoid the problems associated with the need for precision when using two round alignment holes. Therefore they are well suited for home brew, DIY alignment of two sided boards.

Paul A.

--- In Homebrew_PCBs@yahoogroups.com, "crazy_geekchick" <amiegrl2001@...> wrote:
>
> I was wanting to make sure that everything lined up on both sides of a board -- easily. I thought a solution would be to make a registration hole punch. I know the pro ones have cameras looking down the bore of the hole punch, but I wasn't exactly sure where to begin making a diy version of that.
>
> I was thinking a solenoid with some sort of hole puncher, but I wouldn't know where to get precise equipment for the puncher itself.
>
> Any ideas?
>