1952 Monarch 10ee been sitting for 20 years

70dragcamaro · Sep 17, 2014

New here and just bought a 1952 Monarch 10ee been sitting for 20 year the older gentleman told me . Got my roto phase hooked up tonight the DC generator fired right up but the spindle trys to run in fwd and will run in rev but the contacts jump in and out went up to 400 rpms checked rotation looking at it it's running clockwise on the MG any help would be great. Thanks Ken. Loudon Tn

70dragcamaro · Sep 17, 2014

1952 Monarch

stonehaven · Sep 17, 2014

Nice lathe. What's in the red truck

70dragcamaro · Sep 18, 2014

1954 Monarch 10ee been converted from mg to solid state bought it with electric problems another project want to get the 52 going first

Dupa3872 · Sep 18, 2014

Ha Ha I wondered that myself and was going to ask about the red truck. We are such machine whores. Good luck with the lathe it looks like a nice find.

Ron

70dragcamaro · Sep 18, 2014

Thanks Ron

Cal Haines · Sep 18, 2014

70dragcamaro said:
New here and just bought a 1952 Monarch 10ee been sitting for 20 year the older gentleman told me . Got my roto phase hooked up tonight the DC generator fired right up but the spindle trys to run in fwd and will run in rev but the contacts jump in and out went up to 400 rpms checked rotation looking at it it's running clockwise on the MG any help would be great. Thanks Ken. Loudon Tn

Hi Ken,

Welcome aboard!

A common problem with square-dial MG machines is with the 3 big resistors in the upper right corner of the DC control panel (in the big box next to the spindle motor). Check them to make sure they aren't open. If the 2000 Ohm resistor B-E (typically the one on the bottom, right) is open, the forward or reverse relay will open as soon as the armature voltage comes up enough to cause the AP (Anti-Plugging) relay to open (which is around 300-400 RPM).

Also check your DC exciter voltage. You can check it between terminals E2 and E1-2 at the bottom of the panel. Those should be the first and third terminal from the left in the second row. (Always check the terminal label, which is usually above the terminal and metal tags on the wires to verify terminal identification.) You should see about 115 VDC for the exciter voltage.

Cal

70dragcamaro · Sep 18, 2014

I have a parts machine are those 3 resistors interchangeable ? And thanks so much checking them wired up left 1600 right 2000 bottom right open

peterh5322 · Sep 18, 2014

"We are such machine whores."

Yes, we are ... but we are so good at it that a descriptive term better than "whores" probably applies.

Cal Haines · Sep 18, 2014

70dragcamaro said:
I have a parts machine are those 3 resistors interchangeable ? And thanks so much checking them wired up left 1600 right 2000 bottom right open

The chances are pretty good that the ones in the parts machine are bad as well. I bet that many a square-dial machine got sent to the great beyond because of those resistors. The pair of 1600 Ohms resistors can fail and you wouldn't know it, but the 2000 Ohm is a show-stopper.

I would just go ahead and replace them, they're not that expensive. See this link:
http://www.practicalmachinist.com/vb/monarch-lathes/start-up-problem-m-g-machine-265676/#post2034250

You can bypass the B-E resistor until the new resistors show up (I would replace all three while you're there). Just make sure you don't "plug reverse" the motor, which means to change the spindle direction without letting it stop first. The way this works is the AP relay has to be closed in order to start the machine initially. Once AP opens, the B-E resistor provides enough current to keep the forward or reverse contactor closed, but not enough to allow them to close if AP is open. The spindle motor has to slow down enough (and the armature voltage drop enough) to allow AP to close before you can restart the spindle in either direction. AP's job is to keep you from plug reversing the motor, which is very hard on it. And if B-E is open, the forward/reverse relay opens as soon as AP cycles.

Cal

peterh5322 · Sep 18, 2014

"I would replace all three while you're there"

This case, like the diodes in the Module, is one where "shotgunning" makes sense.

It may be well neigh impossible to find precise duplicates, but functional replacements are certainly within the realm of availability.

Allied, Newark or Digi-Key are possible sources.

peterh5322 · Sep 18, 2014

"AP's job is to keep you from plug reversing the motor, which is very hard on it"

The designer was very smart.

He (Greene ?) set the values to allow plug reversing as soon as was possible, while still allowing a 4,000 rpm forward to 4,000 rpm reverse command to be processed within 4 seconds.

This, then, prevented abuse of the machine, while encouraging high throughput.

Cal Haines · Sep 18, 2014

peterh5322 said:
...

It may be well neigh impossible to find precise duplicates, but functional replacements are certainly within the realm of availability.

Allied, Newark or Digi-Key are possible sources.

1600 Ohms isn't a standard value, so finding two of them for a one-to-one replacement is a problem. However, a 3000 Ohm plus a 200 Ohm in series works just fine to replace the 1600 Ohm series pair.

Based on the field failure rate, I don't think the 2000 Ohm was correctly sized or had some other issue, so even if a new old stock part were available, I would stay away from it. (IIRC, a member ordered the resistors from Monarch and what they received was not the same size as the originals.) I actually have no idea what the wattage of the original resistors was. I selected the L50 series (50 Watt) Ohmite resistors based on their size alone. A 2000 Ohm resistor connected to 115 VDC will only dissipate about 7 Watts, so a 50W resistor should "get 'er done".

Cal

peterh5322 · Sep 18, 2014

"But ...whom among us is going to raise a hand and claim/admit sufficient expertise to sort the nuances and the nomenclature?"

Point taken.

However, collectively we have amassed sufficient knowledge that these incredibly complicated machines may actually be maintained.

My guess is no one in Sidney, Ohio ever expected its machines to still be in everyday use 70 years after leaving its (Monarch's) machine erection hall.

70dragcamaro · Sep 18, 2014

Thanks guys got some new ones ordered will give you an update when I get them

waynes · Sep 19, 2014

Cal Haines said:
1600 Ohms isn't a standard value, so finding two of them for a one-to-one replacement is a problem. However, a 3000 Ohm plus a 200 Ohm in series works just fine to replace the 1600 Ohm series pair.
Cal

That should be in Parallel, shouldn't it?? OK - disregard, I figured it out. You're using 3200 Ohms total to replace 3200 Ohms. Thought you were replacing a 1600 Ohm with a 3000 & 200 in parallel. I'll go back to the sidelines...

70dragcamaro · Sep 22, 2014

Here is the update got the new resistor s put in and that fixed the contacts jumping in and out and it run s perfect in one direction but when I put it in the other direction it will turn the spindle but really struggle s you can here it really load the MG. the contacts towards the motor pulley really throw fire when disengaged 2 of them and that is the direction that it struggles. Do I need to clean the contacts and what is the best way and thanks so much Ken

70dragcamaro · Sep 22, 2014

Runs good in fwd struggles in reverse

70dragcamaro · Sep 23, 2014

Thanks Bill will do

70dragcamaro · Sep 23, 2014

I tried 2 but using this tapatalk with my phone maybe I can figure it out but I am from east Tn

1952 Monarch 10ee been sitting for 20 years

Plastic

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Hot Rolled

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Stainless

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Diamond

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Cast Iron

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