Monarch 10EE

did it come with a toolpost? you didnt mention anything about that.

No it did not. I have a KDK toolpost holder however and hope to be able to use that. Thanks.

================== Given the flexability [variable speed, soft start-up] and cost, I suggest you take a very long/hard look at single phase in - three phase out VFDs.

Be sure and clean/lubricate everything. Look for mud dauber nests in the motor air vents. If something is hard to turn or frozen, there is a reason (such as a lock) A bigger hammer is not the suggested solution.

re rubberflex collets see

Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.

John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).

Thanks for the links, very informative. I peeked in the motor compartment this morning and saw no tubes but rather a bunch of relay type devises, a motor generator system then? It was also extremely greasy with lots of chips in the grease. Steam cleaning would be nice but I may need to pull the power motor and associated electrics out? Any way, I will need to finish my build on the rotary converter I've accumulated parts for including a 25 HP 3 phase motor as the converter. I may have to consult with you guys when I'm ready to assemble the whole thing just as a double check.

Here's a Monarch forum to check out:

Randy

I've been thinking about your suggestion for a VFD to power a 3 phase motor in, say a 5HP motor. There have been concerns in the discussions I've read about the low torque in the lowest revs necessary in some lathe operations. If I adapt the backgear onto the 5HP 3 phase motor, will that concern be alleviated? Why do 10EE owners insist on repairing worn out motor-generator or other factory systems other than for original restoration purpopses? It would seem like a clean and fast solution to use a 5HP VFD powered from 220V single phase input.

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======================== IMNSHO the low speed torque problem is a non-starter. Use the gearbox [or change the belts/pulleys or put in backgear] for gross speed changes and use the VFD to fine tune, for example taking a facing cut across a large diameter -- high speed in the center, droping to lower speed at the outside.

The 5 HP motor is for commercial machining and making lots of chips. In most home shops the lathes will *NEVER* be run this hard, making the substitution of a lower power and less costly motor very cost effective. Another possibility is one of the DC treadmill motors, although these seem to be high RPM.

Some people are into restoring old cars and some of us just drive old cars. Its the same for tools, some people restore old machine tools and some of us just use old machine tools.

Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.

John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).

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I think Karl Townsend, who posts here, converted a 10EE to VFD drive. No doubt he could offer some good advice.

Randy

If it requires 3-phase, then it is the motor-generator drive, not the Thyratron drive, which runs off of single phase. You are probably lucky there, as the Thyratron drive can be pretty difficult to fix unless you know somebody that has a stockroom of 1960's industrial controls parts.

Sure. You should be able to turn it over by hand. Mount a hardened and ground shaft of known circularity and straightness in the best collet or chuck you have. Mount a dial test indicator on the toolpost. You can read along the front and top surface of the bar as you move the carriage along the bed. This will tell you how much wear the bed has. It may be meaningless until the lathe is properly leveled with a master precision level, though.

When doing these tests, you can turn the spindle over by hand and average the min and max reading to eliminate any eccentricity or wobble in the mounting of the test bar.

Been there, done that. It took me 22 months to repair the bed on my Sheldon R15 lathe, a 15", 3500 Lb. machine with D1-6 spindle and a 2.25" spindle through hole. I chose to repair the bed by hand with a die grinder and Cratex wheels rather than taking the bed off and trying to find somebody that could grind a 6' long 1500+ Lb lathe bed. I'm not sure it was such a good plan, I had no idea it would take that long! But, I learned a lot, and developed some new skills.

Jon

It is not so simple. The older Monarch 10EE used a motor-generator system, and a MASSIVE custom DC drive motor with integral backgear reduction. Slowing down the motor-generator won't be of much use. Replacing the DC drive motor while keeping the backgear is apparently difficult.

You COULD use a VFD just to run the MG at fixed speed, essentially using it as a phase converter and soft-starter only. That might be an OK option if cost is not a concern. I'm not sure, I suspect the MG could be run from single- phase with a set of capacitors, making it basically its own phase converter, as long as you never needed full power from the lathe.

Jon

I think you may have a lot of trouble to adapt the reduction gear to a standard- frame AC motor. Also, the DC drive of either the MG or Thyratron 10EE's has a much wider speed range, and much more low-speed torque than similar- sized AC motors. I think it is supposed to deliver rated POWER over a 5:1 or so speed range, meaning it has 5 times the torque at low speed as at top speed. This replaces the gearbox seen on most lathes, and is why the EE has only high and low ranges.

With the Thyratron system there's a fixed life on the tubes, and they are essentially impossible to get now. An SCR replacement is possible, but not a drop-in change. The motor-generator is actually VERY robust, and it is not likely there's anything wrong with it (unless you were told it had problems).

My Sheldon 15" lathe can deliver full spindle power from 45 to 1250 RPM, but it uses a gearbox plus backgears to do that in 8 speed ranges. I use a VFD to get in between. That is about what the 10EE was designed to accomplish, before there were VFDs.

Jon

You are likely right Jon, opened the tailstock end of the stand and found what looks like 2 motors, a small one piggybacked onto a larger one. The middle panel reveals a box that looks like it contains a large terminal block with 2 wires off of the bottom terminals taped off. Where can I get a "repair manual" that gives me specific information on this system? Do I have enough information knowing that it is likely a M-G system. Any tips on what info I need to order the manual and wiring diagrams from Monarch that will be direct and specific to my drive system? Is the manual to be ordered from Lucas Precision?

Matching the backgear to an AC motor is a bit of a problem, most of the backgear units have an odd splined input that it integral with the DC motor shaft. I know of at least one person who simply cut off the motor shaft and mated it to an AC motor for the backgear. Monarch just installs a 10HP VFD/motor as a replacement with no backgear.

It works but reduces the power. I don't think the typical HSM ever uses

3HP, much less 5. I've tried to stall the 3HP DC drive and chickened out before it'd stop.

There were several variations. As someone else mentioned, try to get Karl Townsend's attention as he's actually done it. He's chided me several times for keeping the thyratron drive running in my EE. But those flashing purple tubes are just too cool .

As a point of reference, Monarch will retro 10EEs with VFDs and induction motors. They offer a choice of 5HP with the gearbox, or 10HP with no gearbox.

Ned Simmons

There are variations in both the motor output (2 different spline types, at least one using a single square key) on which the backgear slides a gear, and 2 or 3 different backgear cases (a couple that were essentially the end bell on the motor, another with feet that sat on the motor mounting plate and was a little independent of the motor).

But then the lathe was made in quantity for something like 60 years, you'd expect some variation.