Low and high speed spindle motor

[cncor]

I would like to use one motor on a mill capable of doing low speed and high speed stuff.
So I would like a speed range of about 500rpm to 20000rpm or so.

Can I use a HF spindle that does 18000rpm at 300 Hz and use a frequency controller to generate 10Hz to 300Hz for a speed range of 600rpm to 18000rpm?

Does that makes sense?
Do I have any power left at 600rpm?
Anybody already did this before with success?

[Jason3]

Generally, a spindle capable of 20,000 rpm will have a low end minimum of around 2,000 rpm. Usually unless it is a pretty big (2-3 Hp +) HF spindle it won't take a cutter bigger than 1/4" anyway so you might not need less than 2,000 rpm - 2,000 rpm and a 1/4" cutter will deliver 130 SFM, slow enough for most materials, and if you need less you can use a smaller cutter perhaps...

Regards,

Jason