Homebrew PCBs

While not exactly "on the cheap", I think my 
modified version of Harvey's "solution" is very 
cost effective. 
<http://www.instructables.com/id/Motorized-Plunge-PCB-Drill-Using-a-USB-Microscope/>. 
It uses a USB microscope to be sure the drill is 
placed correctly. It can be built for 
approximately $100 USD, including the drill.

Mark







At 07:22 PM 2/15/2016, you wrote:
>On Tue, 16 Feb 2016 00:02:26 +0000, you wrote:
>
> >Thanks for the advice Harvey...I'll look into the methods
> >you suggested.
>
>I have a very quiet vacuum, so it is on all the time with an air scoop
>to remove the board swarf.
>
>
> >
> >Yeah, the swarf  from the board is a problem...have a vacuum
> >at hand, but some kind of automatic "vac as you go" method
> >would be best.
>
>I have a very crude (but quite workable) air scoop made from the
>crevice tool of a regular vacuum.  Works surprisingly well.
>
>You can get very very close with a vertical alignment drill press, and
>not so close when you have to match the hole at an extreme angle.
>
>Harvey
>
>
> >
> >Charlie
> >
> >mosaicmerc@... [Homebrew_PCBs]"
> >>> I use resharpened carbide in my dremel 395 with 1/8" shanks for PCB
> >>> work. They work fine....I go down to around 0.31 mm. I can go smaller
> >>> but bit breaking happens every 10 holes or so.
> >>
> >>>Me too, but I rarely break bits since I switched to a home-brew drill
> >>stand that seems to eliminate any "hand wobble" from causing breakage.
> >>
> >>>My CNC machine can drill lots of holes with resharpened carbide and a
> >>Grizzly pencil-style die grinder.
> >>
> >>>Perhaps rigidity in the holding of the dremel is more important than
> >>runout? Or at least, *lack* of rigidity is more common as a cause of
> >>breakage?
> >>
> >>>Posted by: DJ Delorie <dj@...>
> >>
> >>I purchased a drill stand from Sears quite a few years ago. It
> >>had run-out, but I cured that by tightening/adjusting all the
> >>critical screws that caused the run-out. Works just fine since
> >>then, and no breakage of carbide drill bits either. I'm using
> >>a Dremmel with the collets, mostly the 1/8" size. I gotta say
> >>though that the stand sure is CHEAPLY made....lots of plastic
> >>parts. Once when using the stand, the sector gear that raises/lowers
> >>the drill carriage broke!! (Cheap plastic!!!) I made another gear out
> >>of some thick aluminum and it's been good ever since.
> >>
> >>My bigest problem is positioning the PC board on the exact
> >>center of the pads. My drilling is close but most of the time not
> >>dead-on especially if the pad's center holes don't get etched
> >>away. I installed a 12v light bulb under the stand and
> >>that helps to illuminate the pad locations, but still.....
> >
> >You're looking at parallax as a problem. You're not looking straight
> >down on where the hole should be.
> >
> >One option would be to put a webcam under the board, illuminate the
> >bottom, and drill from there. Your only problem would be the swarf
> >from the board.
> >
> >Mine is upside down, with the camera above and the drill from the
> >bottom. It's a bit more complicated mechanically, and involves some
> >programming and a stepper motor.
> >
> >However, a top drill press with a bottom view (and a vacuum sucking
> >off the swarf) would be a possible good idea.
> >
> >You drill from the side where the pads are.
> >
> >A good set of movable crosshairs (if there's any play) and a test hole
> >when the drill is changed ought to get you very very close.
> >
> >Harvey
> >
> >>
> >>On my drill stand I made a larger platform out of some
> >>1/8" smooth hardboard so I could use a homebrew
> >>moveable fence that clamps to the edges of the hardboard.
> >>Using that sure made drilling easy when I needed to neatly drill
> >>holes in a row like for IC's.
> >>
> >>Charlie
> >
> >
> >
> >
> >
> >-------------------------------------------------------------------------
> >-------
> >Posted by: Harvey White <madyn@dragonworks.info>
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>------------------------------------
>Posted by: Harvey White <madyn@...>
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