Need Help!- EG&G TORQUE SYSTEMS PMDC servo & MOTRONICS PMDC motor Specs ???

[cnc2]

Hi to everyone,

I've just bought two used PM DC motors for cheap,

The first one is a "PM FIELD SERVO MOTOR" from "EG&G TORQUE SYSTEMS" Model NO: MH-2120-003J code: 0283. It also has a sticker with three codes like this: ASM:
E.C:
E.I.R:
the codes were hand written.

The second motor is a "MOTRONICS Corporation" PT.NO. 801679-001 REV.G CAT.NO. 31107-14-210-05 INS. CL. H VOLT 24 DATE CODE 0183. It's a PM DC motor.

If you guys can help me with these:

1) On motor #1(EG&G servo) I have no idea of the voltage, Amp & torque ratings...it's a pretty fast motor, supplied it from 6V to 12V to 24V It's fast at 12V & Very fast at 24V (the bearings are old & whistle a bit)

2) On motor #2 (Motornics) I have no idea of the Amp & torque ratings.

Any info is welcome .

Thanks !
cnc2.
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PS: I had troubles uploading the pics to the Zone, I had too many timeouts even when the file sizes were well below the limit, so, I used ImageShack.

[Al_The_Man]

These EG&G were made by Cleveland Motor Control http://clevelandmotioncontrol.com/index.asp
If you go to the DC motor link on the site you should see 2120 series.
If not I have the original manuals.
Al.

[cnc2]

Originally Posted by Al_The_Man These EG&G were made by Cleveland Motor Control http://clevelandmotioncontrol.com/index.asp If you go to the DC motor link on the site you should see 2120 series. If not I have the original manuals. Al.

Many thanks Al

From the website you pointed I've found this http://clevelandmotioncontrol.com/do...atform2100.pdf & this http://clevelandmotioncontrol.com/do...duct_Guide.pdf and also found an xls sheet http://clevelandmotioncontrol.com/do..._data/2120.xls
On the sheet I've selected "motor winding type: H" because of the MH-2120-xxxx in the model NO. is that correct ? (the sheet said 1600rpm @45V for winding H but @24V it seemed to be spinning faster than that)

I'm a bit conserned about the second motor, the fact that you don't know it might indicate that it ain't no good

Can I change the servo's bearings by myself without the risk of demagnetizing it ? (& loose torque like a stepper)

Thanks !
cnc2.

[Al_The_Man]

I have serviced quite a few without inserting a 'Keeper' but if you want to play it safe, slide a metal tube in place of the armature.
Careful not to damage or chip the magnets.
Al.

[cnc2]

Thanks for the info, I'll see if I can, I'd prefer to work it out safely.
cnc2.

[cnc2]

UP !

I still have no info about the Motronics Corp pmdc motor & have no idea about the bearing it has on the mounting plate, no obvious indication about its previous life....all I know is that it's made in Little Falls NEW YORK 13365

Thanks !
cnc2.

[Al_The_Man]

I would say the bearing on the mounting plate was due to the particular application it was used in. You should be able to just remove it?
For sizing, you can get approximately by comparing physical size with CMC motor.
For voltage, apply a known fixed low voltage DC and measure the rpm, if you estimate a max rpm for the motor to be 2500rpm as a safe guess, then pro rate the max voltage accordingly.
Al.

[cnc2]

Thanks for the reply Al !

I already know its rated voltage it's 24VDC (on the name plate) RPM is lower than the other motor & I think I'll be able to measure it with my bicycle's multifunction digital tachometer, but I have no idea about its rated current & torque. (by looking inside after removing a plastic plug from the frame I can see the winding which seems to be made out of thick wire near the gauge of phone copper wire)

Any idea on how I can know the rated current & torque ? (holding the shaft with a towel I could slow it down but I couldn't stop it of course the reading on the amp meter went up to around 3A if I recall)

Feeding it with 12V & low current I could stop the shaft, but when blocked the motor makes noise sounds like "ggrrrr grrrr grrrr"

Is there a way to replace a broken brush holder ? it's the outside plastic thread which is broken on the EG&G servo.

Thanks !
cnc2.

[cnc2]

Well, I did the test with the bike's speedometer which has an RPM function in it & it all went out OK.

It wasn't very accurate but gave a good rough figure because I was holding the sensor in my hand trying to hold the required distance from the magnet (3mm +-1mm).

The test results:

the big Motronics has a speed of around 1800 RPM (dancing between 1772 & 1800)

the moderate EG&G which looked/sounded very fast, has a speed of around 3600 RPM (the speedometer is rated 3600 RPM max & I saw speeds of 3720 RPM)

All the tests were made with the motors standing vertically on the table.

Thanks for all the help !
cnc2.

[sbe7922]

"MOTRONICS Corporation" PT.NO. 801679-001 REV.G CAT.NO. 31107-14-210-05 INS. CL. H VOLT 24 DATE CODE 0183. It's a PM DC motor.

I used to work in the engineering department of Motronics and may have a catalog burried in my files. I will take a look and get back to you.

[mike_Kilroy]

if SBE, ex Motronics, doesn't find an old data sheet on it, post physical size and voltage/speed you got no load again in 1 single post. from that, various of us will be able to compare it to similar rated motors we design, build, sell, service, and be able to make close guess what its current, continuous torque, and max speed ratings are for you.

[cnc2]

Originally Posted by sbe7922 "MOTRONICS Corporation" PT.NO. 801679-001 REV.G CAT.NO. 31107-14-210-05 INS. CL. H VOLT 24 DATE CODE 0183. It's a PM DC motor. I used to work in the engineering department of Motronics and may have a catalog burried in my files. I will take a look and get back to you.

Hi sbe7922,

Hat's off to the engineers ! this motor is older than me & seems to be in perfect condition, can you tell me on what kind of machinery it was used (for what kind of machinery it was made) ? & what's the purpose of that bearing on the side of the motor's mounting plate ?

Is it suitable to be used as a servo motor ?

When I spin the motor's shaft back & forth with my hand, I hear TICTIC as the direction reverts, is it a sign of failing bearings or just the brushes which are a little loose in their cages & move from side to side ? the motor is quiet while running.

Thanks !
cnc2.