Yahoo Groups archive

Homebrew_PCBs

Archive for Homebrew_PCBs.

Index last updated: 2026-03-30 01:05 UTC

Thread

Accurate drilling, cutting?

Accurate drilling, cutting?

2016-06-20 by Brad

So I’ve etched my boards for my TV Typewriter reproduction.  I’m quite happy with the result, however now comes the hard part – drilling and cutting.

 

For drilling, I have a dremel press with 1/32 and up bits.  I did some experimental drilling with it and managed to drill fairly accurately where I can see the holes.  However, some of the holes were obliterated during my efforts to enhance the PCB artwork, and especially for ICs I’m finding it hard to keep them aligned.  I know I have a tiny bit of flexibility there, but I’d like to keep em straight.  I find it very hard to gauge where the bit is.  I was tempted to get a full drill press for this but reasoned the sight laser probably was going to be too big anyway.  Anyway, advice?

 

The next thing is cutting – I found a fiberglass jigsaw blade and man, it cuts like butter.  But keeping it straight is another matter.. wondering if there’s a better avenue?

 

 

Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by Harvey White

On Sun, 19 Jun 2016 19:35:41 -0700, you wrote:

>So I've etched my boards for my TV Typewriter reproduction. I'm quite happy
>with the result, however now comes the hard part - drilling and cutting.
>
>
>
>For drilling, I have a dremel press with 1/32 and up bits. I did some
>experimental drilling with it and managed to drill fairly accurately where I
>can see the holes. However, some of the holes were obliterated during my
>efforts to enhance the PCB artwork, and especially for ICs I'm finding it
>hard to keep them aligned. I know I have a tiny bit of flexibility there,
>but I'd like to keep em straight. I find it very hard to gauge where the
>bit is. I was tempted to get a full drill press for this but reasoned the
>sight laser probably was going to be too big anyway. Anyway, advice?

You may not be happy with this idea, but I have an upside down drill
press. You might be able to reconfigure the Dremel into this
configuration, but it's a bit of work. If you could put the drill
press up on blocks, put a 45 degree mirror on the bottom so you could
look at the bottom (and then drill upside down), all you'd need would
be a way of figuring out where the drill would hit. If you had a
little TV camera with a pair of crosshairs pasted on the TV screen,
that would work.

Your other problem might be that the bearings in a dremel are pretty
wobbly, but you can do a decent job if you're careful.



>
>
>
>The next thing is cutting - I found a fiberglass jigsaw blade and man, it
>cuts like butter. But keeping it straight is another matter.. wondering if
>there's a better avenue?
>

A shear can work well, but you can also use (from what I've heard) a
tile cutting saw with a diamond blade.

Harvey

>
>
>

Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by Brad Thompson

On 6/19/2016 10:35 PM, 'Brad' unclefalter@... [Homebrew_PCBs] wrote:
>
> So I’ve etched my boards for my TV Typewriter reproduction. I’m quite
> happy with the result, however now comes the hard part – drilling and
> cutting.
>
> For drilling, I have a dremel press with 1/32 and up bits. I did some
> experimental drilling with it and managed to drill fairly accurately
> where I can see the holes. However, some of the holes were
> obliterated during my efforts to enhance the PCB artwork, and
> especially for ICs I’m finding it hard to keep them aligned. I know I
> have a tiny bit of flexibility there, but I’d like to keep em
> straight. I find it very hard to gauge where the bit is. I was
> tempted to get a full drill press for this but reasoned the sight
> laser probably was going to be too big anyway. Anyway, advice?
>
> The next thing is cuttin g – I found a fiberglass jigsaw blade and
> man, it cuts like butter. But keeping it straight is another matter..
> wondering if there’s a better avenue?
>
>

Hello--

You might want to evaluate an "optical center punch" as an aid to
spotting the centers of pads
that you need to drill.The device consists of a base that has a
removable lens-- slide the base over the pad,
center it by viewing the lens, remove the lens, insert the punch and
lightly tap the punch. Remove
the base and drill the hole via the punched point.

73--

Brad AA1IP... Writing from New Hampshire's west coast.

Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by Harvey Altstadter

Brad,

For the pads where the holes are obliterated, us a center punch with a very, very light tap to mark the hole site.  The impression will let you see where the hole goes, and also keep the bit from walking when it hits the pad. You should be using carbide bits.  The steel bits don't last very long in the fiberglass boards, and as they wear, they make ragged holes.

Harvey


On 6/19/2016 7:35 PM, 'Brad' unclefalter@... [Homebrew_PCBs] wrote:
 

So I’ve etched my boards for my TV Typewriter reproduction.  I’m quite happy with the result, however now comes the hard part – drilling and cutting.

 

For drilling, I have a dremel press with 1/32 and up bits.  I did some experimental drilling with it and managed to drill fairly accurately where I can see the holes.  However, some of the holes were obliterated during my efforts to enhance the PCB artwork, and especially for ICs I’m finding it hard to keep them aligned.  I know I have a tiny bit of flexibility there, but I’d like to keep em straight.  I find it very hard to gauge where the bit is.  I was tempted to get a full drill press for this but reasoned the sight laser probably was going to be too big anyway.  Anyway, advice?

 

The next thing is cutting – I found a fiberglass jigsaw blade and man, it cuts like butter.  But keeping it straight is another matter.. wondering if there’s a better avenue?

 

 


Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by <n0tt1@...>

I have one of those optical punches. For me, it was
well worth the money to purchase that. If your buy it
from Grizzly tools, it comes in a kit in a wood box. There's
a holder, two "lenses" with two different marks to locate
the center of the hole you want to drill. Then there are
two types on center punches, one is more pointed than
the other.

One interesting property of the "lenses", which are solid, clear plastic,
cylinders is that they gather ambient light to illuminate the
marks (cross-hair or small circle) and the material you want
to center punch.

So, to use the tool, you use the lense to locate where you want to center
punch, hold the holder in place (it has a rubberized cork bottom so
it won't slip), remove the lense then insert the punch and give
it a tap with a small hammer to make the mark. Simple to use.

Accuracy is certainly well within a few thousandths of an inch.

Charlie

On Sun, 19 Jun 2016 23:02:14 -0400 "Brad Thompson
brad.thompson@... [Homebrew_PCBs]" <Homebrew_PCBs@yahoogroups.com>
writes:
>
>
> On 6/19/2016 10:35 PM, 'Brad' unclefalter@... [Homebrew_PCBs]
> wrote:
> >
> > So I’ve etched my boards for my TV Typewriter reproduction. I’m
> quite
> > happy with the result, however now comes the hard part – drilling
> and
> > cutting.
> >
> > For drilling, I have a dremel press with 1/32 and up bits. I did
> some
> > experimental drilling with it and managed to drill fairly
> accurately
> > where I can see the holes. However, some of the holes were
> > obliterated during my efforts to enhance the PCB artwork, and
> > especially for ICs I’m finding it hard to keep them aligned. I
> know I
> > have a tiny bit of flexibility there, but I’d like to keep em
> > straight. I find it very hard to gauge where the bit is. I was
> > tempted to get a full drill press for this but reasoned the sight
> > laser probably was going to be too big anyway. Anyway, advice?
> >
> > The next thing is cuttin g – I found a fiberglass jigsaw blade and
>
> > man, it cuts like butter. But keeping it straight is another
> matter..
> > wondering if there’s a better avenue?
> >
> >
>
> Hello--
>
> You might want to evaluate an "optical center punch" as an aid to
> spotting the centers of pads
> that you need to drill.The device consists of a base that has a
> removable lens-- slide the base over the pad,
> center it by viewing the lens, remove the lens, insert the punch and
>
> lightly tap the punch. Remove
> the base and drill the hole via the punched point.
>
> 73--
>
> Brad AA1IP... Writing from New Hampshire's west coast.
>
>
> ------------------------------------
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>

Re: Accurate drilling, cutting?

2016-06-20 by AncelB

Well I upgraded from the model 395 Dremel (5K RPM max) to a 20K RPM
adjustable Proxxon drill and it has no run out of significance. I can
do 60+ gauge holes for vias w/o breaking carbide bits.
Also I have a super bright LED placed underneath the press, as I had
with the Dremel press for back lighting the PCB when drilling, it works
very well.
For straight cuts I upgraded from a carbide scribe and snapping to a 4"
mini table saw /diamond blade, and added a small vacuum for dust suction.

No longer have any of the alignment issues etc.
The Dremel is used for grinding and metal cutting and polishing now. I
place no lateral stress on the Proxxon bearings to keep the run out away.

Ancel

Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by hickspj467@...

I use  the optical center punch but I also use carbide drill bits. I get them from Drill City. Look for resharpened carbide bits in lots of 10 or 25. Very good prices and being resharpened they are a bit (pun intended) shorter so somewhat less limber an walk less. Still plenty long enough for PCBs unless you boards are 1/2" thick...hi hi.

73, PJH, N7PXY

Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by James

For cutting, the double-score and snap method is best for me.  Use a carbide tipped laminate cutter ( http://i.imgur.com/o9MPI0D.jpg available at good hardware stores ) and a couple of steel rulers to guide you so you don't go off track.  Score with the cutter on both sides deeply, snap it.  In essence, poor mans V-Scoring.







On Mon, Jun 20, 2016 at 2:35 PM, 'Brad' unclefalter@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
 

So I’ve etched my boards for my TV Typewriter reproduction.  I’m quite happy with the result, however now comes the hard part – drilling and cutting.

 

For drilling, I have a dremel press with 1/32 and up bits.  I did some experimental drilling with it and managed to drill fairly accurately where I can see the holes.  However, some of the holes were obliterated during my efforts to enhance the PCB artwork, and especially for ICs I’m finding it hard to keep them aligned.  I know I have a tiny bit of flexibility there, but I’d like to keep em straight.  I find it very hard to gauge where the bit is.  I was tempted to get a full drill press for this but reasoned the sight laser probably was going to be too big anyway.  Anyway, advice?

 

The next thing is cutting – I found a fiberglass jigsaw blade and man, it cuts like butter.  But keeping it straight is another matter.. wondering if there’s a better avenue?

 

 


Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by Steve B.

Checkout Proxxon, they have a mini drill press I use here at my shop.

Works really well, has a basic guide on it you might be able to use (or make a template) to help with keeping holes straight and lined up.

That's what I do.

On Sun, Jun 19, 2016 at 7:35 PM, 'Brad' unclefalter@... [Homebrew_PCBs] <Homebrew_PCBs@yahoogroups.com> wrote:
 

So I’ve etched my boards for my TV Typewriter reproduction.  I’m quite happy with the result, however now comes the hard part – drilling and cutting.

 

For drilling, I have a dremel press with 1/32 and up bits.  I did some experimental drilling with it and managed to drill fairly accurately where I can see the holes.  However, some of the holes were obliterated during my efforts to enhance the PCB artwork, and especially for ICs I’m finding it hard to keep them aligned.  I know I have a tiny bit of flexibility there, but I’d like to keep em straight.  I find it very hard to gauge where the bit is.  I was tempted to get a full drill press for this but reasoned the sight laser probably was going to be too big anyway.  Anyway, advice?

 

The next thing is cutting – I found a fiberglass jigsaw blade and man, it cuts like butter.  But keeping it straight is another matter.. wondering if there’s a better avenue?

 

 


Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by Howard Chester

Having followed previous and past posts on these topics these are my set-ups,

a) cutting;- I use a cheap builders tile cutter with a diamond blade (the continuous diamond compound rim). the scribe method leaves nasty edges. When used correctly with the built-in water cooling there is no glass fiber dust. tip;- add a few drops of washing-up liquid to reduce the noise.
b) drilling;- having dismal results with the dremel drill and stand I've changed to proxxon drill, stand and compound table (This screws to the stand and has scroll wheels that allows for precision setting in both X and Y axes. gone are the "wandering" bits, snapping of bits non-existent, with near perfect centering of holes. TO THE ADVISORS......BIG THANKS!!!
c) artwork preparation;- on completion of my board layout, I place a copy on the desktop, rename it to xxx final (xxx = your file name) and open. change all of the pads to a 0.5mm hole size before printing. this steps further reduces the "wandering" problem and eliminates the center punch. This step really helps with registration using the "5 holes outside the board outline"method. Most PCB programs allow you to adjust the same type pad size properties on a global scale.

Hope these notes are of some use, and wish you all the best on your current project,
chester

Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-20 by riogrande491

If you have occasion to find a used Cameron micro drill press, don’t hesitate to buy it. They are extremely precise and can run up to 30,000 RPM. I bought a model 164 with the standard 1/8” Yukiwa drill chuck, and had a very difficult time measuring any runout with a Starrett Last Word DTI run against the shank of a carbide drill bit. Specified spindle runout is only 0.0002”, or 0.05 mm. 

The only drawback, if there is one, is that the maximum depth of work is a bit limited, but much less so than with the Dremel. I’ve only broken bits by bumping the work piece against the side of the drill. 

All the best!

Bob


RE: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-22 by Brad

I’m having good results with my dremel – it’s just very hard to see where the bit is in relation to the pad when it’s on.  If it were a convenient push button operation I could position the bit, then just lift a little, hit button, and go.  I’ve not had any drifting issues at 30k RPM with a quick up and down motion.

 

I thought maybe putting a small laser or LED under the center of the base to illuminate center above might help a bit… need to find one among my stuff here.

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Monday, June 20, 2016 4:19 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Accurate drilling, cutting?

 

 

If you have occasion to find a used Cameron micro drill press, don’t hesitate to buy it. They are extremely precise and can run up to 30,000 RPM. I bought a model 164 with the standard 1/8” Yukiwa drill chuck, and had a very difficult time measuring any runout with a Starrett Last Word DTI run against the shank of a carbide drill bit. Specified spindle runout is only 0.0002”, or 0.05 mm. 

 

The only drawback, if there is one, is that the maximum depth of work is a bit limited, but much less so than with the Dremel. I’ve only broken bits by bumping the work piece against the side of the drill. 

 

All the best!

 

Bob

Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-22 by Harvey White

On Tue, 21 Jun 2016 17:20:09 -0700, you wrote:

>I’m having good results with my dremel – it’s just very hard to see where the bit is in relation to the pad when it’s on. If it were a convenient push button operation I could position the bit, then just lift a little, hit button, and go. I’ve not had any drifting issues at 30k RPM with a quick up and down motion.

A very bright light shining through the board will help. You might
also want to try a bright light on the top as well. You may try
putting a mirror off to the side at a 45 degree angle so you can see
the drill bit coming down from directly forward, and at the same time,
from the side. You put the drill bit down with the dremel off, just
barely touching the board (otherwise you worry about breaking), and
then press the footswitch and drill.

Harvey

>
>
>
>I thought maybe putting a small laser or LED under the center of the base to illuminate center above might help a bit… need to find one among my stuff here.
>
>
>
>From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
>Sent: Monday, June 20, 2016 4:19 PM
>To: Homebrew_PCBs@yahoogroups.com
>Subject: Re: [Homebrew_PCBs] Accurate drilling, cutting?
>
>
>
>
>
>If you have occasion to find a used Cameron micro drill press, don’t hesitate to buy it. They are extremely precise and can run up to 30,000 RPM. I bought a model 164 with the standard 1/8” Yukiwa drill chuck, and had a very difficult time measuring any runout with a Starrett Last Word DTI run against the shank of a carbide drill bit. Specified spindle runout is only 0.0002”, or 0.05 mm.
>
>
>
>The only drawback, if there is one, is that the maximum depth of work is a bit limited, but much less so than with the Dremel. I’ve only broken bits by bumping the work piece against the side of the drill.
>
>
>
>All the best!
>
>
>
>Bob
>
>
>
>

Re: [Homebrew_PCBs] Accurate drilling, cutting?

2016-06-22 by mbushroe@...

I tried a different approach when trying to get a low quality, Harbor Freight bench drill press to work. I got a little board camera ($40 color, less for B/W) and made a holder for it with a 45 degree angle mirror. I mounted that under the drill press stage and clamped it down, then made some test holes and marked with tape on the TV screen where the hole would be made. Then I just needed to align the board with the bottom pad centered on the marks on the TV set, and usually I can see the top pad as well and try to line up with the small overlap between them.

   It was easier for me to do because I have several of the little cameras left over from underwater ROV projects.

Mike