Which variable motor drive for lathe?

[houlster]

Short story is I've had a 7" mini lathe for about 20 years and want something bigger. It has to be essentially a bench lathe w/ large spindle bore & things like power feed on cross-slide, separate power feed / threading screws & QC gearbox are highly desireable.

I've found the Weiss WBL290F from DroPros and the essentially same PM-1127VF-LB from PM. (Sorry, I tried including links, but the system told me I was posting spam and it wouldn't work.)

Similarly featured, these are both within a couple hundred in price, not considering quality of the extra items (DRO, 4 jaw, steady, follow, etc). But, the major difference is the motor used.

Dro version has a 2hp/1500w brushless DC motor : 80-2000 rpm (no belt changes?)
PM has a 1hp single phase AC motor with VFD : 70-2200 rpm in 2 steps

Though I've looked at PM machines for years, I have no real brand loyalty. Both PM and DroPros look to be quality vendors. Any large, obvious reason to choose one of these over the other based on the motor drive? It seems like the brushless DC motor is a much better setup, especially for variable speed operation.

(And I might still be able to go with the PM 1228, which has a brushless DC motor as well....)

thx

 

[pacifica]

PM's best machines are made in taiwin. The 1228 has a 7" wide bed which is good, d1-4 camlock, 1 1/2" bore and inch lead screw; all important and preferable features.

 

[houlster]

PM's best machines are made in taiwin. The 1228 has a 7" wide bed which is good, d1-4 camlock, 1 1/2" bore and inch lead screw; all important and preferable features.

Agreed on the 'T' machines. The 1127 has all those same features you mentioned as well. The 1228 adds the QCGB. Been eyeballing the 1340GT for years, but have given up on ever having the room to fit one anytime soon. I can fit the 1127 or maybe the 1228 though and they are about the smallest with the specs I'm looking for.

 

[markba633csi]

The PM machine must be a 3-phase motor if it comes with a VFD unit
Some say the brushless motor systems have more low speed torque
A brushless motor is really a 3-phase ac motor with a permanent magnet rotor
-Mark

 

[houlster]

The PM machine must be a 3-phase motor if it comes with a VFD unit

Typo maybe? From their page:

Variable Spindle Speeds by reliable AC Inverter (VFD) Drive

Variable Speed 120 Volt Single Phase Main Motor, 1hp AC Inverter Drive

Thought it was odd too, but googled it and did find that single phase VFD do exist.

 

[markba633csi]

Single phase input yes, but 3-phase output in this case I think