Help with Power supply or motors ?

[rodzilla]

I have thee new stepper motors they are SanyoDenki StepSyn 710.6 oz/in motors. The specs on them are as follows:

on the name plate here is the specs

12-375V
6A
stall torque 5.09 N.m
1.8DEG

I am also attaching a pdf drwaing of the motors which states rated output to be 2.1V. Could someone please tell me what size power supply i should be running these motors with i have three motors hooked up to 3 G202 Gecko drives and i will be hooking up a fourth axis but it appears that something is wrong with my setup as i have no torque the motors are stepped down 2.5:1 to the Lead screws i will be replacing them and going ballscrew eventually but for now i want to see why i have no Torque. I was told that the Tormach cnc's are running between 400-600 oz/in motors direct coupled and they run with lots of torque but it seems i can't get mine to take small cuts without the motors stalling. I have these motors at work also and when the machines at work are on you can't turn the motr spindle by hand but at home i can take my hand and turn the motor spindle with very little effort i would appreciate some help on this problem as you guys have a way better handle on this stuff than i do.

[rodzilla]

I forgot to mention what i am using as a power supply currently it is a LAMBDA SWS600-48 and when i take voltage measurements from the supply going into the geckos i get 60.1 volts. But when i hook my ground on multimeter to chasis and take measurement of the coil windings i get 30 volt. I am also using a 270K OHM resistor on the current set of the g202 when i measure resistance of the resistor not hooked up i get a reading of 265,000 OHMS, but when the machine is running i get 165,000 OHMS or i get OL

[LeeWay]

I think 52.5 volts is max you can run in that type connection. Your 48VDC sounds appropriate on the volt side.
Optimally an 18 amp PS should be used, but you can get away with less. I wouldn't go any lower than 12A though.
I would use the proper current set resistors to even the amps out as well. If you have a heavy head or gantry, then this would need more amps. If some axes are made of different components, then the ones that move the easiest would need fewer amps.
Here is a link to the specs on one set of my motors.
http://www.kelinginc.net/KL23H286-20-8B.pdf
You can see that amps and voltage needs are dependent on how it is wired up. You can use your spec sheet to help determine what size supply you need or can afford or how you can wire it to get the max from the supply you have.

[rodzilla]

I am using all three of the same motor they afour wire so they can only be wired BiPolar, all three of the drives are gecko G202's these are all running on a HF 33686 Milling Machine the big green one. The current set resistors are the ones recomended by Marriss to use with a 6A motor

[LeeWay]

You will need all the amps and volts you can get then. Probably 48VDC @ 18A. You could get another 48VDC PS and run it parallel with the other one to achieve a higher amp rating. For instance, if your PS runs 9A now, another identical PS would give you the 48VDC with the 18A you need. Parallel connections gives you the sum of both PS's amps and series connected PS's give you the same for the volts.

[rodzilla]

Do you think that i am on the right path given that on one machine i can't turn the motor spindle by hand and the other machine i can turn the motor spindle with little effort. Would this be a safe assumption that the power supply is not producing enough Amperage so by going to a power supply with more amperage i will be giving more power to my motors