Troubleshooting a Module Drive 10ee

Bought about a year ago, life got in the way, finally biting the bullet on getting it running. Serial #48639, have a new manual from Monarch Sidney. It was reported running when removed from service (heh) with some speed control issues (heh).

The speed control pot feels crunchy and I'm waiting on a more electronically inclined friend to set up a test rig for the module diodes, so I'm testing operation with the module removed (which if I understand correctly should also take the iffy pot out of the equation).

Hooked up to mains 3-phase, the warmup timer seems to do what it should, the "control on" button engages PC, the c3j glows, and when I engage the ELSR carriage switch, three things happen:
1) the forward or reverse contactor engages (solidly as far as I can tell)
2) the QSD relay bounces and sparks
3) the c16's pulse as the QSD bounces

I haven't checked voltages yet, gonna wait and do that, along with diodes, under the eye of someone who's actually dug into HV circuits before.


Q1) The QSD seems to have a ton of free movement. It's (I think) the older style, with a big coil on its own phenolic plate. Found detailed pictures on other threads but don't recall seeing specs on contact distance or adjustment procedures. Any ideas (or any hey-dumbo-you-shoulda-looked-here's)?

Q2) Machine is hooked up through a 20a twist-lock, 60' of 4x10ga SO, and a 20a breaker - not going to be a permanent solution, but it seemed like it should allow for testing. Offhand, should I figure out a better feeder before moving ahead with troubleshooting?

Q3) Machine was listed as 3-phase and has 3-phase coolant pump, but the disconnect box had only 3 wire remnants - one per phase - and one was green. No ground/bond wire that I could discern. I wired each phase of my service and brought the ground wire to a case bolt ('cause that SO hookup is just a big extension cord, there's no conduit path to ground). This exact hookup is obviously temporary, but does either the original wiring scheme or my current hookup raise any red flags for basic testing? Should I check if it was re-wired for single phase and if so is anyone inclined to help me cheat on some diagram-reading?

Have a message out to the seller asking for more information and am hoping to catch Tim at Sidney tomorrow.

Down the road, pulling the carriage is the next mechanical task, but figuring out if I can make the drive work at all is the first order of business.

If anyone's still reading, any and all advice is welcome, and if not it's still been useful to get a record of where things stand. I'll be back either way :-)

And lastly, some pictures that I hope I've attached correctly!

P.S. new non-braking resistor is already in the mail, though the existing winding looks intact.

Check that the spindle motor brushes are making contact. If the motor does not draw current, the QSD thinks it should brake, then when there is no current drawn, it thinks braking is done, then the cycle repeats. I recently fixed one with that problem. Someone had replaced the top brush in the motor but not the bottom one, probably because it is hard to reach. It didn't occur to me at first that someone would replace one brush and not the other. You can remove one bolt and take the brush mount out as a unit so you can clean it up. Remember which way the holder goes. If you reverse it, the lathe will run but do funny things like reversing suddenly. (Don't ask)

The brush mounts have slotted mounting holes. Remember to adjust them so they match the track in the commutator.

Bill

Make sure the electronics are well warmed up. On my machine, which is only a few months newer than yours, at lower speeds the QSD will bounce unless the field power has been on for a couple minutes. You may also need to adjust the two little feedback pots in the module to get rid of the bounce. I had to replace my QSD relay and replace the braided wire to the movable contact. I had to adjust the spring tension to make the relay behave nicely. It needs to not stick against the armature so that the braking resistor actually engages. Beware the the QSD contains asbestos.

10-gauge wire sounds just OK, but a 20-Amp breaker sounds small. If the breaker doesn't nuisance-trip, it is probably not causing problems.

My machine won't start with the module removed. The main breaker trips.

You only need single-phase power to run the spindle. Connect two phases (or two 240-V single-phase hot leads) to L1 and L3 at the main input. The third leg should only go to the coolant pump. Search the web for the 1965 Manual and look on p. 13.

Thanks for the suggestions, all!

So, when I first took off the end cover, I noticed fresh(er) paint on the motor, with almost none of the grease and grime of the rest of the compartment/backgear.



"Great!" I thought to myself. "Someone's serviced this recently." Heh.



Someone did, indeed, take it out, do things to it that included painting it, and re-install it. All I know for sure is that they masked the bottom ports of the brush area with some glossy adverts. How do I know, you might ask?




Yep. Still in there, tacked over the bottom ports of the brush housing with carbon and grease on top and shiny gray paint down below. Kohl's had a sale on Wednesday, October 22nd, so a quick google suggests 2014?

Not thrilled with the condition of the commutator, but my experience isn't much. Thoughts from anybody who's seen more than one?

Eeeeet's aliive!!!

Thanks @9100, for the suggestion - minimal brush contact was indeed this particular gremlin.

Jiggled the brushes, went back through startup, and the spindle turns! In reverse, but I assume a line polarity change will take care of that.

Good (?) news is, serial numbers match; it's the original motor. Bad news is that evidence points to a quick and dirty rebuild - the fan leads were cut and scotchlocked, and someone used a chunk of 5-strand flex cable for the pot leads (though maybe that was monarch SOP?). Back to good; the speed control's "crunch" seems to have been a bent gear tooth and not internal to the pot, so I might not have to replace - tomorrow's electronics session should confirm.

But then there's the commutator wear. It obviously ran like this for a while, & while it's current condition doesn't give me the warm fuzzies, neither does the idea of hauling it out and paying for another servicing.

I don't see the adjustable brush ring mentioned earlier - seems like each brush is on its own swiveling arm(s) off two posts parallel to the armature, with timing and clearance set at the same time. Anyone have experience with this style motor?

Got directionality right, but also got ±3500RPM and either some cycling or the ELSR cam timing is iffy. Although headstock oil flow seems OK (drained and replaced with DTE light circulating), I'd still rather be testing at a more conservative RPM.

Looking through previous posts, the overall current symptoms seem to match those in this thread: Monarch 10EE Modular Drive Dead?

Circa-1968 capacitor steel-banded to T4, in that transformer bay I didn't even know existed. Now I understand why they spec clear access to the rear of the lathe.

Does the cap have to be physically secured to the transformer for proper function, or can I just figure out a separate mount for it that's not quite so fiddly? And does it sound like the cap is the right place to look?

Apologies for the stream of posts, and thanks again to all who've weighed in and all who're reading. More pictures and progress to come!

The two Modular motors I have, actually one mine, the other the customer's, have a different brush mount with the spring of rolled up spring steel strip like a rolligon that provides fairly constant pressure. I have seen the type of holder you have on an MG generator but with dual brushes and two springs.

The ring you refer to is probably the one on older 3 hp motors that allows adjusting for best performance. Mostly it is just another thing to get wrong.

The brush track on the commutator will naturally be dark, but yours seems darker than usual and it looks like some wear. You can turn the commutator yourself. Use a V tool bit with a small radius stoned on the point. Copper would rather smear than cut so it must be as sharp as you can make it. The slots look deep enough that you will not need to recut them. Grind the sides of an end of a hacksaw blade so it just fits the slots, on the end that have the teeth cutting on the pull stroke. That will raise burrs so polish them off with 400 grit wet or dry paper. Never mind the stories about grit embedment. Been doing this for over 50 years and ain't seen no embedded grit yet. Do carefully blow the grit out of the slots. When you assemble the motor, clean the brush holders well. They like to stick. wrap a strip of 400 paper around the commutator, grit out, and seat the brushes by rocking the armature back and forth.

I'm glad it is you instead of me who has to pull the motor. I have reached the age that I simply cannot lift one of them. Fortunately, the only one I have had to remove lately is in a shop with a husky twenty something machinist so I can say "Pull that motor" and go get a cup of coffee.

Bill

You should be able to clean up the commutator in place with commutator stones. hitandmiss (Bill) is an expert on this. You might send him a PM.

Cal

That looks like a nice machine. I have used module drives for a very long time, and I would bet your main switch contacts look the same.
The diodes are in snap in holders so they can be replaced, after time they degrade from heat, the two diodes in Rectifier 3 can get hot and degrade faster, leading to crappy performance.
I would take a close look at the contacts on all switches and anything that looks like it got hot in both compartments, a little trouble in the main drive motor contacts, can be hard on the other components as well.

Correction from earlier: directionality was not restored. Every single connection swap I tried resulted in reversed rotation, until try number 7, when I gave up and left.

Yesterday, I pulled the motor and found A1 & A2 swapped in the peckerhead. Whoever was in there before had banded A1-motor and A2-supply with the same color tape, so may have been just copying how it was prior to them. (I also haven't yet traced the supply leads back to boards to check polarity/labeling there).

If those were actually reversed, would that lead to reverse operation? Other troubles?

On to the motor itself... removal actually went more smoothly than I'd feared:



Those two reversed wires were the only issue, though the motor mounting screw setup seems odd to me - nylocks up top as the fixed head of a rotating stud assembly? I'd trust anyone who said it was factory, and doubt I'll mess with it, but...?



Onwards to the reason I pulled the motor - the commutator.

@6100, my apologies - there is a brush mounting/timing ring, it's just almost impossible to see from the front. It's even timed to an earlier mark (2 or 3 paint jobs ago).



Timed though it may be, it was my understanding that the brush and not the brush holder was supposed to be contacting. The lower brush holder currently misses the commutator by maybe .030", but it's got a commutator-hugging curve to it that the other holder doesn't. Also the commutator and the opposing brush show signs of brass transfer.



So I've gotten to talking with my local motor guy, who's happy to take a look, and certain that he can make it run - all we have to do is remove the armature, spray it, bake it, test it, recut it, and re-install. He's done it a million times and it'll only take a week or two.

I suppose if I were the sort to happily drop it in his lap at this point, I wouldn't be posting here to start with, so I had a little dig around the shop.

Someone wanna talk me out of actually going through with this?



Really any thoughts are welcome; I think I can have a nuts-and-bolts discussion with Harry (motor guy) even if I don't end up giving him the job. My options seem to be:

1) stone in place
2) cut in place (then stone, etc)
3) hand off backgear/motor assembly whole
4) tear down, hand off armature

IIRC, tearing down this motor involves rebuilding the gearbox - can anyone confirm/deny?

The gearbox is also shimmed upwards by about .100 - like the mounting bolts, it seems factory-believable, but also cause for question... if definitely not factory, that would steer me towards teardown and bearing/seal replacement. There's been a slight whine from the gearbox area when running, but I've only gotten consistent operation >3000rpm and haven't wanted to run it that fast for very long while still troubleshooting everything.

Last note: electronics (module diodes, caps, and resistors) all checked out OK. The potentiometer crunch was definitely mechanical interference (someone stripped some sheets off the stacked shim), and the pot itself... was definitely electronically NFG. Replacement coming from Sidney as we speak, hoping to reunite it with a better-running motor as soon as it arrives!

Thanks so much, everyone!

Ever more information: I can confirm that the brush spring assemblies are - if not interchangeable with, certainly identical in operation and appearance to, the brush springs in early-teens DC elevators still working away in a good number of hand-operated Brooklyn elevators.

That said, the entire lower brush assembly is oily. How does that happen? Am I gonna need to rebuild the gearbox anyway? It held oil for a year at the same level, and there're no obvious drips through any other part of the motor.

I'm realizing that there are two armature issues: present discoloration from oil and grunge, and historical pitting/damage from brush holder contact and maybe drive issues.

Looks like the worst pitted areas are .020 or so low - is that within the range of a dressing stone?

Not a Monarch owner or user, but common sence would tell me to fix it right now that you've gone to the trouble to take it apart, and then you'll have a few less things to worry about. If you don't have another lathe to turn the armature, get it done. Add new brushes and seat them Done. Check the transmission, overhaul as neccessary. Done and done.

I got round to taking a cover off my motor and found that it also has a brush adjusting ring hardly visible without a mirror when the motor is installed. One more bit of data.

Bill