# Prototrak Mx3 With Dc Motors?



## John655 (Jul 20, 2015)

Hello! First off, I'm fairly new to this world, so please forgive my lack of knowledge. 

I own a Bridgeport S1 with a Hurco KM1 controller. I'm having problems with the KM1 and wanting to switch over to a Prototrak MX3. I currently have everything for the Prototrak, minus the servo motors. My machine already has ball screws, so I'm good there. My concern is that the servo motors on my machine are DC motors. 

Is there a way to make my DC motors work with the Prototrak? Is this possible? Thanks for any help!


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## JimDawson (Jul 20, 2015)

I looked at the Prototrak site and was not able to find anything on the motors or anything on the electronics, so I will wing it here.

It is quite possible that the Prototrak motion controller outputs a +/- 10VDC signal to control the servo drives. If that is the case, then you should be able to use the original servo drives and motors which should accept that +/- 10VDC command signal.

Do you have the model of the original drives, and information on the Prototrak electronics?


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## John655 (Jul 20, 2015)

Thanks for the reply! 

I'll get further information off of them when I get home, but I do know that my motors are 48-60V DC. 

To the best of my knowledge, and I could be wrong, but I believe that the Prototrak outputs 115V AC to the servo motors.


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## JimDawson (Jul 20, 2015)

I looked a bit deeper, it looks like the MX3 uses DC servos, so it may be plug & play.  But more specification is needed.

From the Prototrak manual: ''D.C. Servo Motors rated at 280 in-oz continuous torque for X, Y and Z-axes''

I'll keep digging.
.


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## John655 (Jul 20, 2015)

Okay, cool! I'll get more info on my motors when I get home. Also, on my servos, the encoders are placed on the motors. The on the Prototrak system that I have, the encoders mount to the actual machine, seperate from the motors. How would that work?


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## JimDawson (Jul 20, 2015)

It really doesn't matter where the encoders are placed.  As long as they can read the ball screw position or the table position that is all that is required.

On my machine, I use mag scales on the table and quill.  That is the most accurate method, eliminates any error in the leadscrew and backlash.


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## John655 (Jul 21, 2015)

Here's the info on the motors that are on my machine.


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## JimDawson (Jul 21, 2015)

A couple more questions.  Is that the only data plate on the motor?  What is the black box the the left of the motor in the other picture?


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## John655 (Jul 21, 2015)

Yes, that is the only data plate on the motor. The black box has a threaded shaft that runs through it, and the encoder mounts to the end of it. So I assume that the little belt-driven system is what talks to the encoder.


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## JimDawson (Jul 21, 2015)

OK, I recommend that you send an email to ElectroCraft , giving all the numbers on the data plate, and get the specs for the motor.  That is a custom motor, and I'm not able to cross-reference the part number.  I can't figure out what it is.  Then I would the to get the specs on the ProtoTrac motors.  I suspect that they are close enough and if it were mine I would just hook it up and try it.  But I'm not going to recommend that to you.

You might be able to figure out the ProtoTrac voltage by looking at the motor power supply.  I'm just guessing, but maybe somewhere between 60 to 100 VDC.  If there is 115VAC going to the drives, then they would be 90VDC.


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