Three phase motor choice

[Mud]

You could look at a Chinese spindle that has better torque low down (likely a 4 pole motor), these are sometimes called "constant power" spindles when they have torque that drops off linearly with RPM.

I would be interested to see a link (are you thinking Jianken?), but I got the impression the good ones were expensive and still lacking a bit down low. I'd happily settle for a free Mechatron like Marco Reps...look like usable performance from their 2.2kW unit from ~5,000rpm.

Full disclosure, I do have the spindle I intend to use already - if it proves a massive mistake I can swap on a different spindle later with minimal fuss. Hopefully the picture makes the point (I tried to keep the perspective fair) - it's obviously much bigger than a basic 2.2kW Chinese jobby, but not that big...80mm vs. ~110mm...so also a bit bigger than a basic 3.0kW unit (though obviously unpowered). Consider that a decent amount of the stickout is that particular toolholder, the tidy integral mount (and unpictured belt guard), 30 taper tooling, hydraulic drawbar release, reassuring derating (from 7.5kW / 20,000rpm), I can change the gearing, and that it's rated for use from 0 rpm (though I wouldn't be that mean to the bearings). Cheap, simple motors and VFDs appeal too. I'll concede it's heavy and air-cooled.

I put the 7.5kW / 8000rpm motor I took off of it on the floor, and now I can't pick it back up!