On Thu, 7 Nov 2002, Alan B. Pearce wrote:

*>>The tooling (carbide bits) that these things use doesn't
*>>last that long, and standard pricing is quite high (~$17
*>>milling bits.  Each.)  There aren't a lot of second sources,
*>>either (unlike drill bits.)  Grr.
*>
*>How are the tip of the bits shaped? If they are flat like a normal milling
*>bit then this may be difficult, but if they are V shaped like a countersink
*>bit I would be tempted to try a normal carbide tipped drill as a bit if a
*>fine enough one was available. It may be necessary to grind the tip to a
*>sharp point, but you may get away with it for a quick development board
*>without doing this or using an expensive tip.

Try a normal carbide drill and break it off about in the middle. Wear
goggles. The end will be unbelievably sharp and work fine for milling
phenolic and delrin. The shape is right (one long tooth one shorter and
usually the middle is hollow or recessed due to the bit thickness and
shape). I have used it with success in a pinch. The slight off center
thrust and vibration turned out not to be problems (I used ~20k rpm). It
can also drill through holes (not recommended with a normal router bit).

Peter

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