CNC lathe motor.

[evo4wrx]

Im looking to purchase an AC motor for my CNC lathe im building.

I already have the frame built...x ball screw in double ball screws for 0 back lash. Y ball screw will be in tomorrow I hope.

Ive got a servo motor with a 40 mm timing belt coming of the spindle right now.
It has a 3 arc minute gear system in it.

The spindle is 90mm Dia by 620 mm long 4340 Chromo.

I want to setup a main spindle motor and VFD.
My AC motor skills are a little rusty so I was wondering if someone could point me in the right direction.

Im in Australia so I want to use a 440V 3 phase VFD.
I would like to have decent torque from 50rpm all the way to 2000 rpm...
Want kind of AC motor / brand models would be fantasic and a matching model number for a VFD.

Ive attached some photos of the lathe....next stage will be getting in the dampening granite solution (900Kg's of it) and finishing of the live tooling attachments. Its a gang type tooling lathe.

AT this stage I will be using EMC2 only because Im a linux guru and can code in C. so it seemed like a natural choice.

[Al_The_Man]

No photo's?
Presumably you have three phase available, Many VFD's up to a certain size can be used on 1 phase (3ph out) but not many are made for 1ph 440.
If you want maximum performance and are buying from scratch, although a bit higher cost, I would look at a 4 pole Vector rated motor, these are generally capable of higher rpm than the regular 4 pole motor.
If going a cheaper route, a normal 4 pole motor would be OK up to around 120hz.
I could give some manuf names but they may not be avail down under, perhaps some fellow Aussies will chip in with makes avail.
Al.

[evo4wrx]

Should be a photo...I can see it on mine.

The normal 4 pole motor.....whats the rule of thumb....

Eg , 10KW 3 phase 4 Pole...2800 RPM max....whats lowest rpm I could run it at and still have some usable torque.

[Al_The_Man]

10Kw that is around 12hp, you should be able run up to around 3300rpm, if you only need 2k max rpm, you could use a reduction, this way you will be close to your motor base speed at 500rpm.
Is there gear reduction right now?
Al.

[evo4wrx]

Well that may be enough.....

I only wanted about 2000 RPM.
So I can run about 1.5:1 which will give me about 333 RPM

Seems like a good option for now so I can get the thing up and going and ill hunt about for a vector motor.

Thanks for your help.

Ill get some more build pics up today.

[Al_The_Man]

If you just need to run up to around 3000rpm or so, a regular motor should be OK, probably a bit cheaper, especially on the used market.
Al.