Motor Spec's

[69owb]

I have 3 dc motors that I'm trying to find all the spec's on manly the torque spec's I'm looking at buying amc 50a20dd drives for these motors? The one motor looks really old so I was thinking on replaceing it with something better Brushless or ac?

This is the motor I wont to replace
GE DC motor
Model 5BC79AB512 RPM 1725
70V/50F A25.5/61F SHUNT WOUND
FRAME 79AB GEI 4374 25.5AMP RMS

GE DC MOTOR
MODEL 58CF56TB3A RPM 1750
V70V/50F A18.6/77F SHUNT WOUND
FRAME 56 GEI 580 18.6 RMS

PORTER-PEERLESS
MODEL 183-18-0192-0
FRAME DPM56PF4
SERIAL UF59526

Thanks

[Al_The_Man]

I believe the amps you show are AMC if so they are for permanent magnet motors, the ones you have show wound field.
I can look up an equivalent size of motor shortly.
Al.

[Al_The_Man]

It looks like you would need around 8~10lb/ft (10~11Nm) going by the limited specs, with the amplifiers you show, you will need a DC power supply, you may be able to salvage that from the existing drives.
I just picked up a couple of DC motors this size on eBay for $20.00 each, there is less demand for the large ones, unless it has Fanuc on it.
What machine is it on at present?
Al.

[69owb]

Thanks Al
The machine is a old 1950?? burgmaster horizontal 4 axis mill with 20 tool changer Table size 36x48 It had a ge 1050 control on it with hi-ak drives i'm looking at putting the camsoft system on it. you were saying that amc drive wont run these motors? I was talking to galil and they said my resolver wont work with there card what ppr encoder count would work good for this thing
Thanks

[Al_The_Man]

That was the other thing I was going to mention, that some of the older systems had resolvers. These can be replaced with through-shaft encoders such as Renco, or replace the resolver drive with a shafted encoder.
Also you do not need tach's with modern systems, so if you pick up motors that have, you can leave them disconnected or remove them.
To use your exsiting motors, you would need drives that have field control, as the specs you list, show shunt wound motors that imply a wound field.
Typically, I use 1000~2000 p/rev encoders.
Al.