what phase converter do i need ????

i plan on hooking up a cnc hurco vertical milling machine 10 hp. or so
i live in the usa. is there a specific type of phase converter that works with a cnc machine ??? also i kinda remember reading "in this forum i think" about a guy only hooking up a phase converter to the spindle motor and running the rest of the machine on normal 110 single phase if this is an option on an older hurco kmb1 is it overly complicated any comments greatly appreciated.......

John
I have a home made rotary phase convertor on my Hurco KMB3 . It is a heavy 220 Volt 3 HP motor with capacitors and start relays, and runs my 3 HP spindle motor ONLY.
I separated the power at the door interlock switch , so the phase convertor goes directly to the forward/reverse relay..thats it !
For control power, i just put in 220 single phase to the door switch and made sure that the legs used, were the ones that go to the 2 transformers. The transformers on my machine are 220 in with 120 out for the computer stuff, and the second one is 220 in with 60 volts out for the servos. So I don't know how you can do it with 120 in only?

I have absolutely no problem with this setup after 2 years. The song and dance that the phase convertor builders give you about having to use a "special CNC" convertor is not true with the Hurco..it is rock solid... they may be thinking of having power on all inputs as a requirement....but .
i plan to change my spindle drive to VFD shortly, but will not use it on the transformers as it isn't necessary.

the only problem with this system, is remembering to start the convertor before running a program...you find out quick when the motor contactor clicks on , but the spindle stays stationary ....just abort and start over..with 3 phase running.

i don't know what your HP requirement is on a KMB1 , but 10HP sounds like overkill.
If you run single phase into the controller as above , I think a standard 5 HP would handle your spindle motor if it is a 3 HP unit.
I use a 3HP on my convertor, but I balance my legs and have a very heavy (read..lots of iron !) motor to work with. i also do not max my amps out.
Rich

thanks for the input it is a 3 hp kmb1
or a 10 hp new.......deciding how far i want to go into dept!!!!!lol
i like the concept but does the computer still control the spindle rpm and reverse??
and how do u balance the legs ???

Reverse is not a prolem, as the 3 phase goes through the motor contactors---so the reverse relay handles that.
I have a manual speed changer ala "Reeves drive" (old term), so I crank the varispeed belts up and down.

from the frame of your question,
I assume that you have the electronic speed unit ?
If so, I can't help with that as I don't have any experience to share.
I will look in my stuff John, to see if/what can be done, but I am Not an electronic engineer.

I balance my phase convertors by adding/subtracting capacitors to the circut.
I also have a Amprobe(Amp meter that clamps around wire) to measure the amps on each leg of the pilot motor output (to spindle motor).
I do this while running the spindle at max speed and no cutter load!
The theory is that higher HP is required to run at that speed and in all likeliness, a very small cutter would be used , so a cutter load is small. As you slow down , the work becomes easier fop the motor, but your cutters get bigger and provide a higher demand on the machines HP. So I think this balances out and I don't worry about amps at low RPM's (they are unbalanced at say 600 RPM, but as I start a cut, I can see the load evening out on the legs!)
To balance , you sometimes have to make changes as small as 2 Mfd to the legs. This requires an assortment of "caps" to do this closely.
My general rule is
Running caps (oil) 20 MFD per HP. ( 240 V rated)
Starting caps (dry) 100 MFD per HP (370 V rated)
Depending,on the motor, I have seen running caps go from 12.5 to 22.5 to balance legs