[MSGMachine]

I have a Milltronics Partner knee mill that I am getting ready to retro-fit with mach 3.

I now have only 2 axis, but after I get the x and y axis going I plan to add a z axis.

I am looking at using the viper drive, and I wanted to know if you could recommend a setup for me.

Just to look at the specs it looks like the 100v drive would work, but I am concerned about BEMF (back electromotive force).

My motor specs are attached. (MT30F4-25)

Thanks

[Larken]

The 100 volt drive (Viper 100) has the same power mosfets as the Viper 200 which are rated at 250 volts @ 56 amps, so the back emf isn't a problem. The difference between the 2 drives is the voltage regulator range (25-100V or 50-170V) and the main capacitor (680uF 100V or 390uF 200V)

Also i can build the V100 with smaller connectors (10 amp vs 20amp) if requested, for space and cost savings.

What PS voltage do you plan on running ?

Larry K

http://www.viperservo.com/V200.htm

[MSGMachine]

I plan on running around 90 volts out of the power supply at 20 to 30 amp.

the amp. rating is kind of a gray area for me.
The motors are driving a reduction pulley at 2 to 1, to a .200 lead ballscrew.

If I have calculated right the spike in amp. shouldn't be over 14 or 15 amps per motor.

Does this sound right to you?

And this time I did this time I did attach my motor specs.

Motor #: MT30F4-25

Thanks

[Larken]

I just built a chassis with a 1000 watt 90Vdc PS and 3 Viper 200's mounted on their edge. I will post a picture.
I get the toroids made here in Canada by SumR in Toronto. Costs more than china, but exellent service and quality. I get a 12V 1 amp secondary winding to power the control board in the same transformer.


Those motors should be no problem.
No one ever puts a PS capable of driving all 3 motors continuosly at peak current, unless you know the machine will be at 100% load all the time.
20-30 amps should be fine.

[MSGMachine]

So do you think that I could get away with 3 Viper 100's or do you see a need for me to have the 200's?


I thought there might be a reason you used the 200's over the 100's in the 90 volt system you discribed.