Possible to increase spindle speed?

[jinu117]

I've been thinking,
Is it possible to increase spindle speed to say 6000 RPM or so?
As not too lose too much low end torque maybe put VFD in there with bit larger power motor, etc. Or is it not even worth bothering due to mill spindle limitation?
Things I am machining (aluminum/copper most of time) can really use some ramp up on speed of cutting by increasing spindle speed is what I am seeing...

[SyilAmerica]

Easiest way is to put an air spindle in your spindle now. Have it turned on and off with the G-Code controlled relays.

Air spindles come in a huge range of speeds. Up to 113k rpm. The one I like is the Macro Technologies unit.
Their unit is 30k rpm.

[thackman]

What do those air spindles typically cost?

[307startup]

Boy I hope you have a HUGE air compressor and don't mind listening to it pound all damn day...those air spindles use ridiculous volumes of air. Look for a Lyndex R8 spindle speeder...they typically can run up to 25,000 rpms. They fit in your R8 taper and have a planetary gearing system like an automatic transmission that multiplies whatever spindle speed you have by a factor of 4...

[jinu117]

What do you mean HUGE? I am already using abtou 15 SCFM for my cold air gun? :P Is it something like 30SCFM?

[thackman]

I don't think that I'd have much luck with a spindle speeder, My spindles runnout is .003". I need to do something about that but the head (or column) is out of tram by .007 on the Y so I'm guessing it's going to be one thing at a time.

[307startup]

Originally Posted by jinu117 What do you mean HUGE? I am already using abtou 15 SCFM for my cold air gun? :P Is it something like 30SCFM?

An air driven spindle typically consumes 50-80 cfm.

[jinu117]

Yikes...
Thackman, how did you check tramming? I never bothered since spindle ID (OD wasn't too good but ID was really good below my measuring capability)
WYLD, that sounds like requirement for 3 phase... eeek. Okay, forget that idea. Maybe tormach is in line if I really need to move up than unless Syil comes up with some other reasonable solution.

[Legion99999]

I wonder why they haven't offered some additonal belt pully configurations. Seems like a quick easy fix to a problem for a ot of people. I imagine you could even find some aftermarket models that might work.

You might lose some torque, but additonal rpms would be very nice. have the high speed spindle set up (well i did before it broke) and just another 1700 rpms made a big difference on delrin and aluminum.

legion

[jinu117]

I do have the high speed option My mill came with just about all options imaginable at the time... (pre syil America).
I would love to see something like 6000 RPM on this machine as that can roughly reduce my cut time of copper (yes copper... you are lucky talking about derlin I think :P) by 70-80% from what I've been thinking. (especially when using 1/8 or smaller endmills)
In fact, playing with ME consultant gives me roughly 16000 RPM for optimal RPM for few cuts :P
I have been thinking few things over anyways (I have MT3 spindle now).
I would like to move to Tormach tooling (R8 spindle is required obviously)...
Which means I will have to work on spindle at one point or another anyways...
which means, might as well change bearing to be able to handle higher speed (of course, question would be the accuracy and rigidity of machine parts too)
Change the motor (or more likely put VFD drive in there and control it through 2nd parallel port) rework on pulley if required) (2nd parallel port will actually enable me to get something nice like limit switch inputs... heh)
More I think about, more it will benefit me as long as I can get that higher RPM reliably.

[Legion99999]

U would probably have to change to high speed bearings as well if you got into those rpms...

[jinu117]

Originally Posted by Legion99999 U would probably have to change to high speed bearings as well if you got into those rpms...

Yes, I did think about it of course :P
The thing I am wondering is, how well made are those R8 Spindles as well as rigiditiy of rest of components.. I would love higher spindle speed with some modification but not at cost of losing accuracy... :P

which means, might as well change bearing to be able to handle higher speed (of course, question would be the accuracy and rigidity of machine parts too)