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:
> 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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