I do use HHS when hand drilling but the bits dull very fast and and start to leave blow out on the back side of the board. I keep a small wet stone handy to touch up the points, which helps. My drill is a little 1.5" dia x 2" long Globe dc motor afixed with a pin chuck and a foot switch. Its served me well, drilled thousands of holes. But its time to move up to CNC drilling. For years I have done wet processed boards using photo resist and film masks but now I would like to set up and do double sided engraved boards.
Craig
--- In Homebrew_PCBs@yahoogroups.com, michael tenore <wb2lcw@...> wrote:
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> Its better to use high speed steel or cobalt bits..
> they can be found cheap from Victor machine or travers or on the web!
> The carbide bits break too easy even with a dremel drill press.
> regard
> mike..
>
> --- On Thu, 2/24/11, designer_craig <cs6061@...> wrote:
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> > From: designer_craig <cs6061@...>
> > Subject: [Homebrew_PCBs] Re: Carbide PCB drill ?
> > To: Homebrew_PCBs@yahoogroups.com
> > Date: Thursday, February 24, 2011, 2:26 PM
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> > I was going to buy some from Drill Bit City:
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> > http://drillcity.stores.yahoo.net/
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> > One thing thought, the carbide bits are vary birttle and I
> > found it was not possible to use them with a hand held tool
> > like a Dremel. Not even sure you can use a low quality
> > drill press. The quill runout needs to be fairly good and
> > the down feed needs to be very sensitive or you will snap
> > them. You also need to turn them very fast, they like
> > speeds around 30,000RPM -- some PC drillers use 100,000 RPM.
> > I have had success at 5000 RPM on my CNC Bridgeport mill. I
> > am sure I will snap a few before I get he feed rate dialed
> > in. I have plans for a high speed spindle but not had time
> > to work on it.
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> > Craig
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> > I will be drilling with my CNC bridgeport
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> > --- In Homebrew_PCBs@yahoogroups.com,
> > Cristian <bip@> wrote:
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> > > > I eventually bought a sharpening machine that
> > had diamond wheels,
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> > > > drill bushings and a microscope.
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> > > Let me know where to buy such tool, Tom, please.
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> > > Cristian
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