Working in Plastic and Small Holes...

offset the bushing by the depth of the microplane?

-Nathan

I think I understand what you are saying... However, the bushing guides the drill. It doesn't spin.

I'm not a plastic guru (incognito or otherwise) but I solved that problem by switching to a (carbide) lipped brad-point bit.

Do they make carbide tipped, brad point bits at the 0.029" size?

You're closer to the sources than I am, and I did warn that I'm not a guru. :-)

My understanding is that with the right grinding setup it's possible to re-grind the business-end of an ordinary twist drill into that configuration. I'll guess that it might be possible with a carbide end mill as well.

The Lee Valley catalog used to have a decent photo of the end of a lipped brad-point bit tip - which might be a decent guide for a shop with precision grinding capability. I haven't received a catalog for long enough to know if the photo is still there, but my recollection is that it didn't look like rocket surgery.

Don't know if they are still in business, but if they are, one of my old time customers, Cleveland Twist Drill, could probably help you.

Lew

"Joe AutoDrill" wrote in news:41344$48ab23f7$ snipped-for-privacy@news.teranews.com:

I'm not a guru of anything but it sounds to me like the plastic is melting. The entry point bears the brunt because the drill bit is in contact with it the longest. I have no clue what they're trying to do but 10k rpm sounds like a lot for any drill. In fact I have never encountered a drill rated for that speed. Never looked but if I had seen something like that I would likely have noticed.

Something with a shank smaller than the hole would solve the problem if my guess is even remotely close.

Larry

First, I didn't mean my question as a flame so if it came across as one, please forgive me...

Second... Someone else suggested almost the same idea... I'll provide the information to the customer and let *them* try to find the tooling. :)

I know that sounds like bad business, but one thing is clear when I sell a tool... I sell the drill, but there are sooooo many variables on the tooling that I usually shy away from all but the most basic advice unless I have hands on experience.

Regards, Joe Agro, Jr. (800) 871-5022

See:

CLIP

See:

It sounds as though the bit is mushrooming the soft material as it enters.

Tell them to try a tapered bit.