ELSR question

This may be a dumb question, but when the ELSR is switched to LH, which way does the spindle turn when the control rod/lever is pushed down? I am working on wiring in a VFD and I was hoping that the wires could just be pulled from the ELSR and used to drive the fwd and rev on the VFD. So far, from my reading of the schematics I've found online and the way the switches are wired in the ELSR, it looks like the spindle rotates forward when the ELSR is set to RH and the lever is pushed down or the ELSR is set to LH and the lever is pushed up. Is that right? And normal? I suspect so, since that lets the ramps that return the control rod to center work the same way, but it seems counter-intuitive to go up to turn the spindle forward.

Dave

Another thing I want to add eventually is a VSR. So, related to the original question, how does the lathe know when the lever is pushed down, whether that is backing up the thread going L to R or cutting a LH thread going from L to R?

Dave

Well, I hate when I finally find the answer after posting the question. So, using the ELSR, the carriage always moves to the right pulling up on the fwd/neutral/rev lever. I don't know how long I looked for that, but I kept ending up on the same threads and finally found one with a description of its operation, both LH and RH. Still looking for the VSR answer, though.

Dave,
I have a 1946 10EE with ELSR feature. Electric Spindle Reverse is what it stands for I think. When cutting a right hand thread both the selector on the headstock and the one on the far right of the bed must be set to the right hand position. The spindle runs CCW (looking at the chuck) and the carriage feeds to the left at the pitch setting when the on/off lever is pushed down. When the lever is raised to the reverse position the spindle rotates CW at a faster RPM and the carriage rapids to the right. When cutting a Left Hand thread both selectors must be set to Left Hand. Now the spindle still turns CCW with the on/off lever pushed down but the carriage moves at the pitch setting to the right.
Raising the lever to reverse position again reverses to spindle to fast RPM and the carriage moves rapidly to the left . The spindle speed and the lead screw speed are adjustable by a variac on the back of the machine. There are even adjustable stops on a rod that move the lever to the off position with a pretty close repeatability. Very nice Monarch feature that makes threading pretty quick especially on short threads. Of course you can still use the engage/disengage the 1/2 nut method and watch the thread dial. If your going with the VFD that would probably be the easy route to take.
spaeth

If your ELSR works like that, then it's backward from the wiring descriptions I found and what the manual for a later machine says. Maybe the VSR has something to do with that. I can't tell since I don't have one. So, I wired it the way I have found described and as such the spindle turns CCW and the carriage moves toward the headstock when set to RH with the lever pushed down. When set to LH, the spindles turns CCW and the carriage moves to the right when the lever is pulled up. This is how it is described in at least one manual. I also note that the ramps that return the control rod/lever is shaped so that when operating this way, after the rod is centered, there is a "overrun" area. The ramp on the opposite side of that part ends at the back of the opening. I guess a picture would make more sense. TBH, it would make more sense to me if pushing the lever down always turned the spindle CCW, but it just doesn't seem like that was the way they intended it on my machine.

I'd be really interested in how the VSR is wired in. I can make mine work when I get around to adding that feature, or maybe I should say, if I do. But, it would be nice if I can just replicate what Monarch did.

You can use it either fashion by selecting the appropriate setting on the two L/R controls. If your doing external LH threads you want spindle ccw and leadscrew cw but if you're doing internal LH threads you set the spindle cw, leadscrew ccw and cut on the back of the hole.

I have an ELSR and a VFD. The control need to be set so that the spindle turns CCW with left or right hand threads. The knob function is set because the Ramps on the dogs that disengage the control lever only work in one direction. So to stop the carriage moving right to left, the dog followers must be rotated down, and when moving left to right the dog followers are rotated up.

The increase the spindle speed in reverse, I wired a switch from the reverse enable micro switch in the ELSR housing, to a programable input on the VFD, the input adds 20hz to the speed setting. You need it to be switchable off, since that extra speed is not always wanted in reverse. It is not simply adjustable like the Monarch version. But works fine as is. 10 years.

I will have to think about the VSR, as I don't really see me using reversing function of the ELSR function on a routine basis. For inch threads, it's just too fast to wheel the carriage back by hand.

I hadn't really thought of the other inputs on my VFD, but like mentioned, it's a programmed speed, and I don't think I want it to work that way. I am thinking since I am using a 0-5VDC input for speed, I could just wire in an additional pot and just have it switched out. I could wire it in parallel with the main speed control, or I could make it its own independent circuit.

Yeah, maybe that feature never gets implemented or used.

Yes that could work, a forward pot and a reverse pot. Don't know what the system logic does as it switches from one to the other pot, and senses an open circuit, or just a very quick move.

I use the ELSR for metric threads mostly, which I used to do often, now only rarely do I cut Metric.

It doesn't seem to care. In operation, the switching from one pot to another would be between moves. As long as the fwd or rev enable are not active, it shouldn't be doing much. From what I can tell, even if it were to jump while running, it would just try to match whatever input it was receiving, though.