[bsharp]

I just got an old TREE 320 mill I would like to get going in my garage. The first thing I did was clean the thing up a bit and replaced a set of brushes in one servo that where bad. The next was to see how I could run this thing on single phase. I had figured that the spindle was 3 phase and I would need a converter for that but I had no idea the servo amps would be also. they are "Gettys N360 THREE PHASE HALF WAVE CONTROLLER" 240vac max, 60hz, 12.5Amp. My question Is there a way I can re wire these to run on single phase. I have a complete schematic of the driver.
What I was thinking was trying to connect 220 to X1 and X2 and move T2 white to X1 and T3 BLK to X2. Any help is greatly appreciated before I blow this thing up .

[Al_The_Man]

No1, I would be rather leery about putting large three phase SCR servo drives fed from a RPC, which is shared by the spindle motor.
Is the spindle drive also three phase? Either also SCR DC or 3 phase motor direct?
Also it would appear from the schematic that I only see one armature lead from the SCR bank, which could imply that the return would be to a 3 phase star point. Star connected transformer.
I don't seem to see it on the print.
I think T1,T2,T3 are phase sense transformers for the firing circuit for each phase.
Al.

[bsharp]

I did not like the idea my self of feeding the drives from a RPC. Thats why I got thinking about possibly modifying the drives to run on two phase. The spindle drive is also three phase. It is a "REULAND" shown below with brake. Also is the 360 interconnect and main power distribution schematic "my machine has no "knee motor" or "flood coolant"".
Thank you very much for your help

[Al_The_Man]

As I suspected, the three phase requires a current carrying neutral, i.e. the return for the motor armature.
You may be able to run them on 1 phase SCR drives, but there may be a problem from using the existing drives, in any case, you would only need to use two of the phase inputs as using the 3rd would be redundant, If they are Gettys, they are probabally fairly high (current ) torque motors.
The DC energy (mean current) derived from 3 phase per cycle is higher, obviously than the equivalent 1/2 wave 1 phase.
What kind of CNC control is on it, or do you intend to replace it?
If the machine is going to be used for production, I would tend to look at replacing the DC drives with PWM, used in torque mode style, and put a VFD on the spindle, 1 phase in - three phase out, this way you also get CNC control of the spindle speed, which in your case can be doubled (120hz), due to being a 4 pole motor.
Al.

[bsharp]

The motors are "Gould - Gettys" 12.5 AMP. I think the control is an old Milltronics built Spartan. Could you recommend a VFD that would work well for the spindle.
Thanks a million for your help

[Al_The_Man]

What kind of spindle controller is on right now, as I see there is spindle overide on the panel, this would indicate a spindle controller of some sort?
Al.

[bsharp]

It has a small motor controlling the CVT. It is separate from the axis servos.

[bsharp]

I think i am going to replace the old amps with G320's run from a PC and get an L200 VFD for the spindle. The only question now is what am I going to do with all the empty cabinet space?
Thanks a million for your help