If you can't tell from the pictures, this CNC is old as dirt (cobwebs, dust, etc).

That said, it works (mostly, but not quite).

The stop-switch sensors, plugged into 10 (x-axis), 11 (y-axis) and 12 (z-axis) are sort-of working. The z-axis only has one stop, and it works. The x- and y-axis have 2 sensors; the y-axis works, but the x-axis does not.

The sensors in place are Optek OPB815. These are optical photovoltic stop switches. The x-axis sensors are dead.

The CNC system came with extra/spare parts, in particular, DEFOND SPDT physical switches.

I've used the following test setup:

https://www.cnc4pc.com/pub/media/productattachments/files/3_c10r10.pdf

X- and Z-axis works just fine. Y-axis does not work, no matter what I've tried.

• Swapped out X and Z leads for Y.
  • Swap X and Y.
    • X works fine, Y doesn't work.
  • Swap X (originally Y) and Z.
    • X and Z work fine, Y does not work.
• Put everything (labled) back in order.
• Swapped out switches on the test bench leads.
  • Repeated above routine.
• Double-checked all switch leads and voltages across the test bench and CNC4PC C10_rev7 pins.
• Switched from pin 11 to 13 (CNC4PC_rev7)
• Re-configured software (CNC Pro v9, DOS, 32-bit).
  • Repeated all of the above on each iteration.
• Also checked, double-checked, and played with the Hi/Low settings in the software (CNC Pro v9, DOS) -- in all of the above test-bench scenarios.

Finally, I put the original Y-axis system (photovoltic sensors, OPB815) back in place, and everything works properly (at this point, the Y-axis is on pin 13 instead of pin 11).

FYI: The original system (photovoltic sensors) receives (resistor regulated) power from an independent system, opposed to the CNC4PC diagram which works for the X- and Z-axis, but somehow not for the Y-axis. Whereas, in attempting to replace (test bench I'm writing about here, not working for the Y-axis)

I also checked BOTH ends of the parallel port cable, including the outputs from the CNC4PC C10_rev7, and everything is signaling right.

In other words, I'm left scraching my head. X-axis photovoltic sensors are shot, does not work. Switch over to diagram provided by CNC4PC (newer than the C10_rev7), X- and Z-axis work just fine (x-axis fixed, Z-axis now has 2 switches instead of 1), according to the diagram, but Y-axis stops working. (Normal growing pains? Irony?) It just doesn't make sense. It should work, sans an issue with the CNC Pro v9 (DOS) software. This system worked for many years churning out custom BMW part replacements, and reviewing as much as I could find in terms of a change-log history behind CNC Pro v9 (DOS) -- I can't spot any software issues, either.

I'd prefer not to have 2 different systems in place (photovoltic and physical) working on this CNC.

If anyone has any thoughts or ideas about how to keep a consistent (physical switch) system, I'm all bits (NC) and volts (NO).