Voltage and Servo motors

[dgalaxy]

Hi i have 2 glentek 26inch pound servo motors with 200v rutex drives on a bridgeport series 1 . My motors call for around 120vdc i was wondering if i run them at 67 volts for now will i have alot of problems loseing position and loss of power . or will i just lose my top speed. just wondering if i could run this for awhile till i can get a bigger power supply. just wondering if i will lose position and power? or will i just lose top speed

Thnaks John

[Al_The_Man]

You will lose maximum rpm, and if there is insufficient voltage to deliver the required current you will experience loss of torque.
Al.

[TOTALLYRC]

I agree with Al and it has been said before, amperage is torque, volts are speed to generalize a little.
If the motors can pull the amps from you power supply you will not loose any torque, but you may be way down in speed. It will probably be right around half of max speed. I would try it with what you have and then if it doesn't work the way you want you can always upgrade the power supply.

Mike

[dgalaxy]

thanks so much for the replies i think when i buy my third motor im going to go with sem dc brushed instead of glentek


John

[TOTALLYRC]

Originally Posted by dgalaxy thanks so much for the replies i think when i buy my third motor im going to go with sem dc brushed instead of glentek John

Hi John, I got lucky and picked up 4 brand new SEM servo motors ,on ebay,that are a perfect match for my machine. I paid like $25 each plus shipping. If you know what you are looking for Ebay can be a great place to search.

[wmgeorge]

Originally Posted by TOTALLYRC I agree with Al and it has been said before, amperage is torque, volts are speed to generalize a little. If the motors can pull the amps from you power supply you will not loose any torque, but you may be way down in speed. It will probably be right around half of max speed. I would try it with what you have and then if it doesn't work the way you want you can always upgrade the power supply. Mike

Ok, My quick question.... would 3 motors rated at 30 vdc, run without a problem on a 27.0 to 27.4 power supply... without faulting a servo on intensive XYZ movements??

[TOTALLYRC]

Originally Posted by wmgeorge Ok, My quick question.... would 3 motors rated at 30 vdc, run without a problem on a 27.0 to 27.4 power supply... without faulting a servo on intensive XYZ movements??

The quick answer is it depends. If you are faulting out because you think it is the power supply voltage not allowing the motor to go fast enough, then reduce the maximum speed in ipm under the motor tuning tab tp prevent the motor from going faster than it is capable of. You could also lower your acceleration down to 8 or so. Your corners won't be as sharp but it will help on the faulting out. Unless you have other problems.

My big mill with the sem servos goes 200 ipm on the z and only 75 on the y because the y motor is on its way out.
My small mill only goes 10 ipm because that is as fast as the drives will push my motors.

So I guess what I am saying is to set the speeds to what the motor will do, not what you would like it to do. I found this out by trial and error on my machines.

Mike