vmipacman
Cast Iron
- Joined
- Nov 21, 2014
- Location
- Virginia, USA
Hello, It's good to finally be a member. I have frequented PM for years and spend a lot of time on the forum but usually can find the answers to my questions by searching. I finally have a question I would like to ask and get some different perspectives on. This is pertaining to spindle speeders.
I have been needing to use as small as a 1/32" EM on my CNC kneemill. For the last couple projects most all of the tools have been smaller than 1/4" and I am struggling with the max RPM of the bridgeport. 4500 rpm is still very slow for such small tools and I hate running the machine wide open for hrs at a time. I searched for a high speed spindle option but could not find one for an R8. I have designed a spindle speeder/multiplier instead that I think could be used when I need higher RPM's. I considered several other methods such as air or electric spindle or gear drive but felt this had its own set of benefits. My plan is to build this for myself, but was hoping I could get some input on this concept. I guess I am also trying to gauge whether this is a common issue others encounter and how they solve it, i.e. is there a larger need. If spindle speed on bridgeport's is a common issue, is there an aftermarket solution I have overlooked? (Everything I have found is several thousand dollars and designed for a CAT40)
Pros:
-1:6 ratio
-timing belt drive, dampens vibrations and easy to maintain
-power taken from main spindle
-maintains original zero
-easy tool change
-ER20 collet
Cons:
-Run out, TIR of main spindle is compounded with run out of speeder. Hope to achieve .0002-.0004" TIR on the speeder assy alone.
-Deflection, I expect 1/4" EM max in aluminum.
-Loss of ~.5" Z travel due to torque clamp
Usage:
I would use this for 1/8" tools or smaller. Engraving would be a good use. Expected max rpm would be around 20K. Not meant to replace an actual high speed spindle, just provide a stop-gap measure if you must use a tiny tool on a bridgeport.
I look forward to your replies. Thanks, Paul
I have been needing to use as small as a 1/32" EM on my CNC kneemill. For the last couple projects most all of the tools have been smaller than 1/4" and I am struggling with the max RPM of the bridgeport. 4500 rpm is still very slow for such small tools and I hate running the machine wide open for hrs at a time. I searched for a high speed spindle option but could not find one for an R8. I have designed a spindle speeder/multiplier instead that I think could be used when I need higher RPM's. I considered several other methods such as air or electric spindle or gear drive but felt this had its own set of benefits. My plan is to build this for myself, but was hoping I could get some input on this concept. I guess I am also trying to gauge whether this is a common issue others encounter and how they solve it, i.e. is there a larger need. If spindle speed on bridgeport's is a common issue, is there an aftermarket solution I have overlooked? (Everything I have found is several thousand dollars and designed for a CAT40)
Pros:
-1:6 ratio
-timing belt drive, dampens vibrations and easy to maintain
-power taken from main spindle
-maintains original zero
-easy tool change
-ER20 collet
Cons:
-Run out, TIR of main spindle is compounded with run out of speeder. Hope to achieve .0002-.0004" TIR on the speeder assy alone.
-Deflection, I expect 1/4" EM max in aluminum.
-Loss of ~.5" Z travel due to torque clamp
Usage:
I would use this for 1/8" tools or smaller. Engraving would be a good use. Expected max rpm would be around 20K. Not meant to replace an actual high speed spindle, just provide a stop-gap measure if you must use a tiny tool on a bridgeport.
I look forward to your replies. Thanks, Paul