Good Day CNCers. Does anyone know if there is a 6mm collet that can be used in the Sienci Spindle? Thanks
Depending on which spindle you have, if you google “6mm ER16 collet” or “6mm ER20 collet”, you should be able to find some suppliers.
@TDA might be able to answer if a 1/4" collet will safely accept a 6mm bit.
Thanks. I also found Elaire Corp makes reducers (1/2==>6mm, 3/8==>6mm, and 1/4==>6mm). I’ve reached out to see which they’d recommend.
Usual preface, I’m with PreciseBits. So while I try to only post general information take everything I say with the understanding that I have a bias.
As Chucky_ott said. You just need the same ER size as the spindle. Unlike ER nuts, ER collets are a standard design across anything that is the same ER size (ER11 ER16, ER20, etc.). Quality (things like runout) will vary by manufacturer/seller. What quality you will need will vary based on your application.
In term of if you can use a 1/4" collet with 6mm shank… It’s complicated. The short version is that it is inside the clamping range for both ER16 and ER20 (+0/-1mm). However, the runout and slip resistance isn’t ever guaranteed for anything but the spec of the bore of the collet. It will also likely cause the collet to wear faster if repeated used this way. Simple version is that if you have a 1/4" that is made within spec, and it’s not a critical cut that you need with a 6mm, you can use it.
On collet reducers. Be VERY carful. In general they should be an option of last resort. The more interfaces you add between the tool and the spindle the more runout and slip issues you can have. It’s not to say they are never useful. But they often cost more in the long run than they will save you.
Hope that’s useful. Let me know if there’s something I can help with.