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Subject: Re: Drilling

From: "chris" <chris@...>
Date: 2010-02-01

--- In Homebrew_PCBs@yahoogroups.com, "James" <jamesrsweet@...> wrote:
>
> So what do you guys use for drilling boards? I have a cheap drill press which is barely adequate for occasional drilling, but there's enough slop in the quill that it's extremely difficult not to snap off <1mm bits. I've had the best results using the manual mill at a friend's machine shop but it seems silly to use a 3HP spindle to turn a .85mm bit. I almost bought one of those little Dremel stands since I have a couple of the rotary tools but I've heard they are flimsy and don't work well. Is there a good low cost option or am I best off just building something myself?
>

I use one of several options depending on how many holes in what I need to do..

I used to used a home made drill press made form a couple of chunks of wood with a piano hinge, but haven't bothered to get it out of the cupboard for a long time.

Now, for just a couple of dozen holes I use a very old minicraft drill with a miniature chuck.. it must have done millions of holes up to 4mm in plastic as it was installed in a big jig as part of a bigger tool I used when I had a factory. Yhe problem is not breaking drills, even though I use 0.6mm carbide.. its repetitive strain injury... my wrist starts to nag and I know its time to stop

For more holes, I have a micro mill, which I converted to CNC some years ago.. I mounted a proxxon IB/E onto the side of the head specifically for drilling pcbs.. It is accurate and my wrist doen't hurt.. Its not ideal though, as the mill has dovetail ways, a lot of mass and inertia, small motors and is not the fastest traversing machine..

Partly built, is a CNC drilling machine using round carbon steel ways with teflon bronze bushes and proper ballscrews.. I'm hoping this will be about 5 - 10 times faster than the micro mill.. but I'll still use the proxxon as the spindle.. it's just too good not to !

The proxxon is very good value for money.. it knocks spots off the dremels for quality.. One of the best features is the hard steel 3 jaw collets.. they are vastly superior to the aluminium 4 jaw collets on the dremel

as far as drills are concerned, I use almost exclusively reground 0.6mm solid carbide.. picked up 100 from eBay a while ago and I still have 70 left.. ( i get 100s of thousands of holes in non-fibreglass boards) For bigger holes (I need some 1mm ones here and there) I drill with the 0.6 and enlarge them manually with the minicraft drill.


You did ask :-)