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10EE VFD wiring suggestions for ELSR and drum switch


Feb 6, 2021
This machine came to me without any of the original drive components, just a 5hp motor and an old VFD. I'm going to upgrade the VFD to a larger size so I can run it single phase and I want more of the modern wiring options.
My question is, what to do with the drum switch? I really like the idea of using the apron ELSR controls to control the spindle, but I've seen some youtubers speak about the drum switch lever having a much more positive engagement than the ELSR controls for forward/reverse.
I have a nebulous idea of wiring a relay to switch control from drum to ELSR when the drum is in neutral, and switch back to drum when the ELSR is in neutral, but I don't know if this is dumb.
I'm going to have the original motor-generator switch to enable the VFD, and I'm probably going to stick an encoder or hall-effect sensor somewhere in the system to have closed loop speed control because just because. add a lockout for the spindle lock, and use the factory potentiometer gearbox and housing for speed.
I really like the idea of using the original controls for the lathe.
Is there any suggestion for a better use of the drum switch?
Any other suggestions while I'm in the planning phase?

I have some time before this needs to be decided. I'm still in the teardown/cleaning stage.

In the Monarch sticky section .
Look under Monarch improvement rebuild , titled,
"Almost finished 30" I/M. His machine has both head stock switch and ELSR switch.

Screwball on utube has a works in a drawer 10ee that has both headstock and ELSR controls.

There was also a guy on the Monarch that has a 10ee with both controls, I haven't seen him post in a while.

Keep us posted

Screwball and the mentioned thread both are using stock - ish drive systems. Gives me some ideas. I need to get creative.
Reviving an older thread - but I think this will work...
Finally reached the point where I am starting to wire the lathe up. I think I may have a simple way to use both drum switches safely. I'm thinking of using the bottom switch of the ELSR, which is closed when the rod is in the "center" position, to switch the VFD signal COM to the headstock drum. Also using the headstock drum to switch COM to the ELSR. This way,
1. headstock switch will not work unless ELSR is in "center" position
2. ELSR will not work unless headstock switch is in "center" or neutral position.

Anyone see obvious gotchas with this? I'm going to have the Motor Generator switch panel turn the VFD 'ON', and going to have at least one emergency stop somewhere.

I saved the ELSR matrix from a thread on here a while back, whoever made this thanks!


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Just a suggestion, feel free to ignore it. Copy the logic that Monarch used with the ELSR switch... Otherwise anyone who knows 10EEs will have difficulty running your machine. The ELSR has built in cams to actuate three switches. I've installed ELSR on two machines that did not come with it. I also added VSR to both machines. If you have copies of the correct wiring diagrams its not hard to figure out.
This is an attempt to copy the stock ELSR logic operation with a VFD. Handles and cams all run the same way, but the 'neutral' position switch is un-needed by the VFD.
Turns out, the VFD takes a fwd/rev lockout into account with it's internal logic and treats a combined fwd/rev signal as a STOP command. Don't need to do my fancy COM signal cross switching, So I wired up ELSR using only the top two (fwd and rev) switches, set the variables in the VFD and everything works!
VFD logic matrix:
Lapond 7.5kw VFD, single phase input.

All I have to figure out now is how to use the Motor Generator start/stop switches to 'enable' the VFD, as of now, if it's plugged in, it works. For a later day, however. Back to the day job for a month or so.
My 1960 EE with ELSR.I converted 15+ years ago. Now has VFD and 5HP 3 phase motor.. Here is the wiring I used, Push pull knob turns on VFD. The apron F/R lever sets direction, down FWD, Up REV. The linkage in the ELSR box . from the Enable micro switches. This to the VFD direction input terminals, on the VFD.. Th direction wires are in series with the micro switches, in the ELSR .
so in my setup the VFD , So VFD id hot as long as the PP switch is pulled out. You do NOT want to make the vfd cycling ON/OFF.

Send PM if unclear.