Monarch 10EE and VFD conversion

If it's an MG setup, that's a DC motor in there, not the 3-phase needed for a VFD. You'd end up gutting it, finding a 3-phase motor that would fit, then hooking up a VFD to that. That's if the DC motor were a complete wreck, they can usually be overhauled reasonably easily, if needed. If the machine was really cheap and in really good shape, it might be worth it. Old electromechanical DC motor controls are usually pretty robust, they don't take an EE degree to fix. No way to really know that without a personal inspection, though. Unless it's got a metric leadscrew, it's not going to cut metric without conversion gearing. Most older US-made lathes don't have metric leadscrews, at least the ones that weren't exports to start with.
Stan
Reply to
stans4
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Found a 10EE in the SF Bay Area on Craigslist,
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Generator model, says ready for VFD conversion.
What all is involved in doing this conversion and what is it likely to
cost me assuming I don't have lots of time to shop for bargains on any
needed components?
Will the 10EE cut metric threads native, or does it require transposing
gears? If the latter, how hard is it to locate the required parts?
Anyone here see this lathe in person and know anything about it's
overall condition? The trip down would burn a day for me and I've got
lots of work. Looking for an engine or toolroom lathe and there's a few
on CL that look promising. Might come down to what comes with the most
tooling ready to run. I've always wanted an HLVH, but a 10EE is
something I think I could live with...
Jon
Reply to
Jon Anderson
This may be of interest to you.....
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Gunner
"Confiscating wealth from those who have earned it, inherited it, or got lucky is never going to help 'the poor.' Poverty isn't caused by some people having more money than others, just as obesity isn't caused by McDonald's serving super-sized orders of French fries Poverty, like obesity, is caused by the life choices that dictate results." - John Tucci,
Reply to
Gunner Asch
Btw...Leigh down at MarMachine just took in an absoultely georgious 13" Clausing Colchester and will be putting it up before long.....Its an 8015 as I recall..and is loaded with everything..including a DRO....
Which in my professional opinion..while not as "cool"..is a superior lathe.
Gunner, donning his flame proof suit and ceramic armor....
"Confiscating wealth from those who have earned it, inherited it, or got lucky is never going to help 'the poor.' Poverty isn't caused by some people having more money than others, just as obesity isn't caused by McDonald's serving super-sized orders of French fries Poverty, like obesity, is caused by the life choices that dictate results." - John Tucci,
Reply to
Gunner Asch
Just got off the phone w/seller. All are DC, this one is the generator type, not the tube type. It came out of the optics lab at Stanford. There was some speculation from the guy running the lab that the problem was just a switch, but since nobody knows, it's being sold as a retrofit.
He mentioned two approaches to retrofitting these, one is to do away with the gearbox and drive the spindle direct, this loses back gear. The other is to machine some sort of adapter to fit a 3ph motor to the gearbox. If I were to go for this, I'd prefer the latter and would love to hear from anyone that's done it. But would like to solicit input on the two approaches.
I need another project machine like I need a hole in the head, but this might turn out to be a decent deal...
Jon
Reply to
Jon Anderson
Bingo!
Same here.
Hope you got your armor ready Iggy.....
"Confiscating wealth from those who have earned it, inherited it, or got lucky is never going to help 'the poor.' Poverty isn't caused by some people having more money than others, just as obesity isn't caused by McDonald's serving super-sized orders of French fries Poverty, like obesity, is caused by the life choices that dictate results." - John Tucci,
Reply to
Gunner Asch
Given money and space, I'd really want an HLVH and a 16x60 engine lathe. Given that I don't have money and space and can only fit one lathe, no matter what I get, I'm going to be limited.
An HLVH or 10EE won't handle big stuff, a good size engine lathe isn't going to give me the precision and RPM I often need.
I'm likely to encounter mostly farm type work in Oz, but that's if I decide to really go into business there. That would call for the engine lathe. But if I am going to (finally) have my shop just for me and my hobby tinkering, then I want the tool room lathe.
The issue of greater importance is how long is it going to take me to get this thing up and running. I do have an Omniturn, but I absolutely must have a manual lathe available, so even if it's a good deal, if it's going to take several months to convert, I'd have to pass. Decisions, decisions...
Jon
Reply to
Jon Anderson
The tube kind can be difficult to fix, it has 4 thyratrons that can be close to impossible to get replacements for.
The all electromechanical type is quite a bit simpler. You have two control systems. One reduces motor field for the high-speed range, the other regulates the generator field for the lower speed range. Both are generally just big rheostats in series with the respective field windings.
Jon
Reply to
Jon Elson
Oh heck, not going to flame anyone here! I'd REALLY rather have an HLVH, but a -lot- of people rate the 10EE very highly, and I know in good running condition they are worth a lot. He's got accessories for it that would probably cost as much to buy as he's asking for the whole thing. So it's at least worth considering. I'm thinking the project aspect of it is going to kill the idea. I'll have enough of a project just moving things around to get the manual chucker out of the garage and bring in anything, let alone haul (another) project home.
Hmm, ok, looked at the PM link. Looks like the mods for a gearbox conversion really call for an engine lathe, which I don't have, and don't have access to. Not one good enough for this sort of work anyway. Looks like it's a pass for me.
Now, if that was a low hours HLVH out of a Stanford lab and needed the vari drive rebuilt, I'd jump on it for $2500..., and wouldn't be asking questions here that might alert a potential competitive buyer...
Jon
Reply to
Jon Anderson
The generator sort of Monarch 10ee has a three phase motor at the line side, spinning a generator which produces DC of the needed voltage and current, and then the speed control feeds voltage separately to the rotor and the field -- first increasing the rotor voltage as the speed is turned up, then holding it constant and reducing the field current, resulting in faster and faster spinning.
Later ones use electronics to produce the DC for the spindle motor -- and some are more difficult to fix because they use tubes which are rather rare and expensive these days.
The latest have solid state electronics which are also expensive to fix.
The simple form of conversion mentioned is simply putting a VFD between the three phase input and the single-phase power line.
A much more complex one involves removing the three phase motor, generator, and DC motor, and installing a higher horsepower three phase motor in place of the DC motor. A friend in the local metalworking club did this -- and had to do a lot of metalworking to come up with a proper mount for the three phase motor.
Or -- Monarch will do the conversion for you -- for lots of money. This may be what he is talking about. And if so, it means that the current motor/generator and DC spindle motor may be bad, thus the factory conversion is the best bet.
The gears and leadscrew produce inch threads normally. I don't know whether there is a place to put transposition gears or not. (I've not actually used one to that extreme -- just the old motor-generator one at work where I never needed to cut metric threads, so I never opened up the left-hand side of the headstock.
But -- if so -- the threading dial will not work when doing metric threads (a common problem with any lathe with an inch thread leadscrew) -- you will have to stop and reverse the lathe spindle to back up as you wind the tool out of engagement with the workpiece while in reverse, and then wind it back in as you switch to forward. You can't release the half-nuts and expect to cut the same thread path on another pass.
A lot greater distance for me. I would have to take two flights to get there and back in a single day (if I were lucky). :-)
The 10ee is a very good machine. Even one as old as the motor/generator style. (But you may have to turn the commutators and replace badly worn brushes.
Good Luck, DoN.
Reply to
DoN. Nichols
Craigslist,
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Not a single one. I'm not sure what the voltage the motor wants is, but you need two controls to duplicate what is built into the system once you have the ability to generate sufficient voltage. (Since the thing has a three-phase motor turning a generator to produce the needed DC, there are no bets as to what the voltage is. They may have gone for low voltage DC or high voltage (each has its own benefits and drawbacks), but you need two variable voltages -- the one for the motor's rotor (increased up to a certain maximum speed and then you start turning down the voltage (and thus the current) applied to the motor's field to get even higher speeds.
If the motor/generator and the spindle's DC motor are all in good shape, you can just put a rotary converter on the input instead of a VFD and use the lathe as it is. But the fact that he is pushing it as "VFD conversion ready" suggests that there are problems with the motor-generator or the DC spindle motor.
Good Luck, DoN.
Reply to
DoN. Nichols
Can someone educate me a little bit. If the drive motor is DC, and has separate field and main windings, why can't it be controlled by two separate DC power supplies?
Reply to
Ignoramus3281
So -- you could luck out and be able to fix it easily to run from real three phase or a rotary converter, and not need a VFD.
My suspicion is that it is a problem with brushes in the generator or DC spindle motor.
This latter is the approach the friend in the local metalworking club took. It was not a quick project, but he did a beautiful job.
A heavy (but good) decent deal.
Good Luck, DoN.
Reply to
DoN. Nichols
I have a 10EE. I LOVE THAT LATHE.
I did the VFD mod keeping the backgear box. Its a bit of a pain to build, sounds like you don't have time. I'd suggest getting a 10 hp. thee phase motor and 10 hp. VFD. You'd have it running the same day. Super easy.
I bought a pair of gears from Scott Logan to do metric 47 and 37 IIRC. You just put them in the threading gear train.
This lathe could be a pretty good deal. Tooling is VERY expensive and you've getting a lot with this machine. of course, condition is everything.
I would buy the 10 hp. 3 phase motot used from a local jockey. i get one that size for $120 at a place where you just stop and pick it up. Check automation direct for cost of a 10 hp VFD, I'll guess $1K without looking.
if you do buy it, I'll go into detail.
Karl
Reply to
Karl Townsend
This is how Monarach does it without a back gear. You need a large motor to have enough torque at low RPM.
Yes, this is direct drive. Just toss everything out in the bottom of the machine. Put a pulley on the motor and hook up the VFD.
Karl
Reply to
Karl Townsend
you'll never come close to using 10 Hp. Like you said, give it a couple seconds to get to speed and you could go pretty small. have one of the local EEs check me but I'd use 30 amp 240 single phase. Bet 20 amp might work.
karl
Reply to
Karl Townsend

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