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Monarch 10EE oscillating power issue

Brusko

Plastic
Joined
Oct 6, 2015
Have had this lathe at the machine shop I have been working at for as long as I can remember. Whats going on is when I power up the lathe and start it up going forward the mag for that direction keeps opening and closing causing the chuck to start and then stop and then start and then stop ect. It does it for both directions but forward direction does it a lot worse then reverse. I have a video of the mag opening and closing and took other pictures of the lathe. We are running 3 phase power to this lathe and believe it is original.

The lathe is a Monarch 10EE 1952

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Monarchist

Banned
Joined
Oct 2, 2012
Location
Sol, Terra
Have had this lathe at the machine shop I have been working at for as long as I can remember. Whats going on is when I power up the lathe and start it up going forward the mag for that direction keeps opening and closing causing the chuck to start and then stop and then start and then stop ect. It does it for both directions but forward direction does it a lot worse then reverse. I have a video of the mag opening and closing and took other pictures of the lathe. We are running 3 phase power to this lathe and believe it is original.

The lathe is a Monarch 10EE 1952

Overdue for scheduled maintenance - perhaps by a score or two of years - is probably all there is to it.

An MG unit given proper 3-Phase won't need much money or time to put back to rights.

Primary suspect is that the exciter - that DC generator sitting on top of the Primary motor-generator - needs a new belt, a commutator clean-up, and a set of brushes purchased and fitted.

It provides 'full' DC power to operate the relays and contactors, 'weakened' power for the field of the final-drive motor.

Secondary suspect is that one of the four brushes OF the final-drive motor has worn to where it sticks, then doesn't - interrupting the power to the motor.
One of my motors was doing that.

There is a THIRD commutator and set of brushes in the main DC generator of the MG - the lower unit in the last photo.

Monarch lathe LP have new brushes for all of those, and at reasonable prices.

They will need the serial number of the lathe. And you should order an also-reasonably-priced full manual and schematic set for it if you have not already done so.

Next up is cleaning and burnishing the contacts on relays and contactors in the 'DC Panel' you have swung open. Also check for one or more wires - especially on the back of it - that have separated... usually right at the end where they are attached.

Sliders on those two pie-plate-sized Ohmite potentiometers need to be clean, etc.

There are but two bearings in each of the final-drive motor, the motor-generator, and the exciter. Replacements are not expensive. The ones in the final-drive motor's GEARBOX are tedious to replace, otherwise it is basic motor rebuild stuff.

Good time for a pair of new belts for the spindle, one more for the MG to exciter.

Idler pulley bearings pack it in, so see to those as well. And a new flat-belt for the surfacing drive.. and the idler bearings on THAT one.

Also to drain flush, and refill all the oils and make sure the carriage oiler system is working.

Since you do not (yet) need to do any sort of 'conversion', the whole Magilla will take some TLC and clean-up time, but parts should cost LESS than freight and rigging alone to get this one out and a new lathe in.

Even if the new lathe was 'free' for the hauling.

And you surely will not find one 'for free' that is a match to a 10EE. Nor, easily, at ANY price.

Bit of luck, lube change every six to 12 months, another set of brushes every 2,000 power-on-hours.. and it could still outlast many of us here.

So I'd call it worthwhile to just pay back the overdue maintenance 'debt' that has been allowed to go unpaid....and put 'er back to work for another long run of years.

:)

Bill
 

Brusko

Plastic
Joined
Oct 6, 2015
Thank you so much for the quick reply, we have access so a full electric motor repair / re-wind shop. I will be going over everything listed and give it the love it needs, it has been neglected for too long.

Thanks - Jon
 

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ

Monarchist

Banned
Joined
Oct 2, 2012
Location
Sol, Terra
Jon,

I'm 99.9% sure that the problem is with the two of the three resistors in the upper right corner of the DC panel. If you check, you'll probably find that the series pair of 1600 Ohms resistors is open. It's a common problem with that panel. Don't waste any time checking the exciter, etc., until you've checked the resistors.

More here: http://www.practicalmachinist.com/vb/monarch-lathes/start-up-problem-m-g-machine-265676/

Cal

Cal is probably right..

...but PLEASE don't just band-aid patch the machine. A proper going-over will prevent all sorts of aggravations going forward.

And they always happen when you have a tight deadline, so next thing you know, someone has scrapped it when it didn't really need all that much money spent to run for years and years longer with low/no hassle.

Bill
 

david5411

Plastic
Joined
Mar 24, 2013
Location
Florida
Cal is right. I had the same problem and did what he said and it fixed it. (He told me how to do it).

Also, thanks to Bill for the maintenance list. I will add to my To Do list.

David
 

9100

Diamond
Joined
Nov 1, 2004
Location
Webster Groves, MO
A customer had a similar problem. One of the brushes on the generator showed a bright point on one edge and no sparking on the rest of the brush. All I did was turn the power off and wiggle the brush to make it slide freely in its holder. That cured the problem. I tried to invoke Steinmetz's billing, "Wiggle brush, $5, know which brush to wiggle $495" but they wouldn't pay.

Bill
 

Brusko

Plastic
Joined
Oct 6, 2015
Cal, thanks for the suggestion. It was the 1600ohm resistors. Works like a champ. Will be performing other maintenance on it to get it caught back up.
 
Joined
Oct 1, 2010
Location
Maine
Hi CAl: I read your reply - My 10EE has the same issue - but... initially, the reverse did the same start and stop, but now the reverse does not work at all. I took out and cleaned the spindle switch and reinstalled, but reverse still does not activate. Reverse will work if I jump the circuit.
I will order the resistors you specified in the post. Will these resistors correct the no-reverse issue too?
Thank-you for the information in your posts!
 

Cal Haines

Diamond
Joined
Sep 19, 2002
Location
Tucson, AZ
Hi CAl: I read your reply - My 10EE has the same issue - but... initially, the reverse did the same start and stop, but now the reverse does not work at all. I took out and cleaned the spindle switch and reinstalled, but reverse still does not activate. Reverse will work if I jump the circuit.
I will order the resistors you specified in the post. Will these resistors correct the no-reverse issue too?
Thank-you for the information in your posts!
It sounds like something else is going on with reverse. What do you mean "Reverse will work if I jump the circuit"? Where are you placing the jumper?

Cal
 








 
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