I'm considering adding a high speed spindle to my CNC Sherline mill. However, I'm not sure how high a speed I need.

What I need is the ability to machine aluminum with a 1/32 inch cutter. Additionaly, if I'm going to get a faster spindle, I figure I might as well get one that can handle engraving.

I'm debating between the following:

1. Sherline's 10k rpm pulley set
2. Sherline's High Speed Engraving Head (54k rpm)
http://www.sherline.com/8900pg.htm
3. Wolfgang High Speed Spindle (30k rpm)
http://stores.ebay.com/Wolfgang-Engineering

I'm leaning toward the Wolfgang spindle. Will the pulley set be too slow? Will the engraving head not have enough torque?

My 'gut' (historically quite ignorant) tells me that the Wolfgang spindle will do what I want, but I've never hear anything about these spindles; good or bad.

Any advise would be greatly appreciated,

-Archie