1/8" Collet for Bosch Colt

[Mike OMelia]

Well, Bosch does not make one, and I am unwilling to use a bushing. With a 1/8" shank, it is clear I am doing detail work and do not want any runout (to speak of). I did find an excellent option at precisebits.com. The kit is $69 and includes a collet nut and one 1/8" collet and one 1/4" collet. Anybody have experience with this set? And does anybody know of other options (no bushings)?

My bits are endmills from 1/32" to 3/32" (thus my fear of runout, TIR)

Mike

[Mike Henderson]

You could use a Dremel instead of the Colt.

Mike

[Mike OMelia]

Yes, but in that case, I worry about bearing runout. Plus, the fixture I am using is designed to accept the Colt base. The reason I went to this fixture was because I did not like my results with the dremel.

Mike

[Mike OMelia]

I guess I am surprised this is an unkown issue. Or unresolved.

Guess I get the precisionbits collet.

Mike

[Mike Package]

I use a Colt in my Rockler CNC Shark. I have ordered bits with bushings from precisebits.com. One of the bits, a .023 spiral bit arrived broken (not a huge shock, I guess), and they promptly replaced it, no questions asked. The bits with bushings work well but I'm not doing super-detailed work. I guess my point is, based on my experiences with them I wouldn't hesitate to try their collet.

[Mike OMelia]

Just before I placed the order, a fellow I know reccomended using a bushing insert. He does the kind of work I do. I admit, I was surprised. I would have thought potential runout would have been too much. So, for $4 +S&H I am willing to try it. I know about the concerns with bushings. So we will see. If the test fails, then I will buy that precision set from precisebits.com.

Thanks!

Mike

[Mike Henderson]

I've used a bushing but with somewhat larger bits than what you're using. No problem when I used it.

Mike

[glenn bradley]

I've had a 1/2" to 14" bushing that was poor ($5) and one that was fine ($12). I would not worry about a quality bushing based on that experience. Please tell us how it turns out.

[Mike OMelia]

Apparently, precisebits.com exists for the home hobbyist CNC folks. TIR (total indicated runout) can be a serious concern for these folks when doing detailed work. And AFAICT, they are the only ones making a 1/8" collet for the Colt. They gaurentee TIR of less that 0.0004". The only caveat to that is if you have a "faulty" Colt. If the cone seat is off just a little, it will not work (well). Luckily, that is rare. Of course, this is not really Bosch's fault in that they did not design it for such use.

I am prolly gonna get one of those sets in the future.

Mike