[sbalder]

I'll be picking up a Milltronics Parnter Mill with the remains of a Centurion 5 control for possible retrofit. The original servos are still attached and I am wondering about the possibility of using them with Gecko servo drivers.

Can anyone give me basic specs or information on these motors? Are they dc brushed? What voltage/current do they need? Any thoughts on using Gecko 320's to drive them?

Here's a link to a mill with similar looking motors:

http://cgi.ebay.com/Milltronics-Part...QQcmdZViewItem

[single phase]

Those could be DC servos. If they are like mine, they have two wires for the DC armature, two wires (thinner) for the tach. and eight wires for the encoder.

[Al_The_Man]

They were common motors used on Knee mills of this vintage, made by SEM, they are fairly high torque motors and rated at 75vDC to 120vdc 40"/lb to 56"/lb torque at stall, 13 ~ 15amps at stall.
The amps are probabally Westamp or equivalent, analogue/velocity DC drives. Can be a real source of problems.
Al.

[awerby]

Rutex drives might be a better bet, if they're available.

I got a similar machine (a Ramco RamMill from Leadwell, with a Centurion IV control and Westamp servo drives) and ended up scrapping the motors, controls, and most of the electrics after trying various things to make it work as was. Every time I fired it up, some ancient piece of hardware would die - plastic buttons would stick, relays crap out, encoder give up, CRT fizzle - it just wasn't worth dealing with after a while.

The Centurion V might be a little better; if it could be induced to take drip-fed commands from a PC it might be worth nursing along, but there's a lot to be said for all-new (or at least newer) electronics. On the other hand, you've probably got some good iron, and ballscrews on all 3 axes, which is better than starting with a manual machine.

[sbalder]

Thanks to everyone, any info is helpful. I pick the beast up tomorrow and will see what kind of shape it is in.

[sbalder]

As an update I have been tearing into the machine for the past 2 nights. The servo motors are, in fact as described- 40 oz, 140 volts, 11 amps, 8-wire encoders. One of the encoders is junk, but the other 2 give a nice clean signal on my (rarely and poorly-used) oscilloscope. The motors turn nicely at about 350 RPM on a 12 volt power supply.

The iron is dirty, but in good shape. I think it's worth bringing this back to life with the original motors, Larken Viper drives, new encoders, and of course new controls and wiring.

[single phase]

Please post pictures and keep us updated as you go along!


Cheers
Dave

[fcycles]

i just had to pull the x axis servo motor to clean out the commutator for the tach , the table was getting erradic on the x , now it just tosses spindle drive error whenever i try to take it out of estop , anyone out there know how to reset the axis drive on a partner 1 early 90'S , or is the encoder just confused?

[nchapin]

Hi,

I am in the middle of a similar retro fit. I am using the Gecko 320 servo drives and so far they seem happy with the 53 volts that I am sending through them.

I could find no information on the encoders but they appear to be the same as yours. I guessed on how to connect them to the servo drives and it appears that luck was with me. I suppose that I should go buy a lottery ticket.

For control I have a Gecko G100 and am trying to communicate using Mach 3. Righ now I am trying to learn enough about the Mach 3 to get the relay (GPO) outputs to fire so that I can test the relays that operate the knee motor, coolent pump, etc.

Best of luck on your project, I'm looking foward to hearing how it turns out.