I’ve just finished a boxford vmc190 conversion to linuxcnc
I can confirm that what doddy says about the lenze controller 10v and ground terminals floating at a rather high voltage
My lenze grd floated at 110 volts and the terminal which needs to be at 10volts to get full speed floats at 120 volts all measured against the machine ground
There is an isolation board which should be bolted to the end of the lenze controller
The lenze connects to the isolation board using terminals 7,8 & 9 from memory. The isolation board then connects to the BOB and it isolated the floating voltage of the lenze controller

On my vmc190 the isolation board had failed so I had to work around the floating voltage issue. I used a diycnc board which uses step and direction from the BOB and creates an isolated 0volts to 10volts that is feed into the lenze. There is also a relay on the diycnc board which is used to switch the lenze controller on and off. It all works perfectly
My vmc190 is now installed in the workshop and not that easy to open up the electronics bay but I did take some photos of the wiring so ask away and I will help where I can

Cheers. Paul


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