I know of a 10EE that has been sitting unused for in excess of a year, so it is obviously not necessary for daily operations. I am thinking of approaching the shop supervisor/plant manager to find out what they would sell it off for.
What would be a good price? It appears to be in excellent physical condition(with exception of drive system). Fully tooled.
The motor/controls have been taken out and I assume that something is hosed up. I haven't talked to the maintenance supervisor yet to find out exactly what it wrong, but it must not be simple. It has been taken apart, as I said, about a year.
Assuming the controls/motor are shot, what is the best way to repower this?
3rd party DC controller? 3ph motor and VFD? Other?
I worked at a place that had a 10EE repowered with a big vari-drive. Though it worked well it was a pain in the ass to crank the handle of the vari-drive because of it's location behind the machine. If I did it today I would use a three phase motor and a VFD. Big DC motors are expensive and so are the controls. I have two machines with 10 HP DC spindles and DC drives. When one blew and I looked into a replacement drive. The drive alone was way more money than a new three phase motor/VFD package. And that was for a 15 HP AC motor because of torque lost at the lower rpm. Three phase motors are cheap used and are pretty bullet proof. And VFDs are getting better and cheaper all the time. BTW, the DC drives in my machines are Randtronics which was bought by SWEO who discontinued them. Sweo was later bought by Baldor and is now Baldor-SWEO Drive as far as I know. Instead of replacing my Randtronics drive I lucked out and found Electrical South who repaired them for a flat $500.00. I don't know if they still charge this price but they had great service and even talked to me over the phone when re-installing the drive. Eric R Snow, E T Precision Machine.
In part, this depends on how old the machine is. 10EE lathes have had various ways to drive the motors over the years. (All but the most recent have had a DC motor driving the spindle through a custom gearbox, so hanging another motor on it involves quite a bit of metalworking to do it right. (One of the members our our local metalworking club has done exactly this, and it was an impressive job.)
The oldest of the 10EEs received three phase power to spin a motor-generator. This fed developed DC power which was to the DC motor through two rheostats.
One increased the power to the motor's rotor as you adjusted for higher speed.
The other, running from the same speed control knob, *decreased* the field current at the higher speeds.
This resulted in a DC motor which could produce lots of torque at low speeds, and very high speeds without switching belts or anything of the sort.
Later ones replaced the motor-generator with a circuit using thyratrons (tube equivalents of SCRs), with quite a few high power ones in use in one machine. I've seen postings from people who are experienced electronics technicians and engineers who were having trouble figuring out how it worked -- even with a proper schematic diagram. The thyratrons are currently *very* expensive, and you don't really want to be buying them every few years.
Still later ones used solid state circuitry to develop the control signals to the same old DC motor. There were two versions of this -- one with most of the control circuitry potted, so you have to replace it as a unit (again very expensive), and the other with individual components (somewhat less expensive to repair *when* (not
*if*) it fails.
Finally, they have started producing refurbished machines with an oversized three-phase motor build into the original gearbox, and a VFD to control the speed. The oversized motor is to attempt to maintain something like the low-speed torque which the original DC motor could provide.
So -- how much work it will be to get it running depends on which of these version it happens to be (almost certainly not the last listed), and how good you are with electronics -- or how much in the way of other machine tools you have to do the conversion to adapt a three-phase motor to the machine.
All told, however, when it runs, it is a *beautiful* machine, and I would love to have one.
Second that, Don! Beautiful and very complicated. Sort of the Mona Lisa of the metalworking world ! I helped a friend go through the control circuitry on one of the 1964 "thyratron" models. It was a wonderful example of what could be done with "tube" electronics. Two new thyratrons later and an expensive trip to the bed grinders, he is still working on it - now doing a little hand scraping on the cross slide, I think. Long story short: He invested in a 10EE because he likes to work on old machinery; in fact he bought a 2nd one for parts. His dream is coming true -- he still has a lot of old machine to work on. Yeah, I'd love to have one also to work with - not work on.
This is a "newer" machine. Without looking it up, I would guess 70's or 80's vintage. It has the square speed selecter, flame hardened bed, and few other things that I think are indicative of later model 10EE
I suspect this is the case.
I'm not bad at electronics. :) But I do enough of that during the day. I make chips as a diversion from thinking "electrical". I have a reasonably equiped home shop w/ machinery capable of way more than the operator is(at this point anyway).
I'm going to see what I can get this for. Considering it's current state, and the plant manager I might be able to get it pretty cheap. It will be a bit of a project(just what I need), but the potential rewards here look pretty promising.
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