Light Machine Corp. Benchman XTr (retrofit)

The spindle PID loop is controlled entirely inside the DDM-019 based on the +/- 10V from the computer.
The encoder signals were brought back into the nextmove system for rigid-tapping type operations where we would slave the Z-axis to the spindle rotation.
The DDM-019 analog feedback lines were used to monitor the spindle speed and the spindle load.

Thanks for clarifying that! Much appreciated. I got it to move with a 1.5V battery after I set the motor enable. Any idea why, with no command voltage, it makes a high pitch noise and spins at very low rpm? Do i need to tweak the PID in the controller or is there an easier method (since I don't have a serial port XP laptop)? Should the spindle enable be on when the cnc turns on or just when turing on the spindle?

Even a few millivolts on the command line will make the spindle spin very slowly.
Do not enable the spindle until you are ready to run it.

Ok makes sense, thanks. Do you know what the clocking/anti-rotate pins in the spindle and tool changer carousel are for? I'm onto programming the toolchanger and it would make the program much easier if I didn't have to home the spindle rotation, I'm thinking of removing those pins.

Side note, If you're ever in Toronto area in Canada, let me know, I'd love to buy you a beer, I would not be as far as I am without your input!

The anti-rotate pin is exactly that. With the cylindrical shaft on the toolholder, there is significant force on the toolholder during heavy machining and we found that the toolholder could slip inside the drawbar. The addition of the anti-rotate pin addressed this specific issue. It did however make the toolchange procedure more complex as you now have to rotate the pin in and out of the locking position. If you are not doing heavy machining with larger tools (> ≈ 3/16" dia) or machining that requires z-axis slaving, you are probably ok to remove the pin.

Ok thanks! Knowing that, Ill probably go the extra mile and use the clocking pins, I would like to machine with larger than 3/16" dia at times. Thanks for the insight!

Hi there,
My machine is 98% complete, tool changer took the longest. Just wondering what does the 2nd prox going into the spindle to? One is for spindle orientation and the other I can't seem to find information on.

The second sensor monitors the drawbar. We don't want to start the spindle while the drawbar is open.

Hey guys! Wow! There has been a lot going on here since the last time I had time to mess around with my BenchmanXT. My machine is back home and its time for me to get back on it. At this point, I have everything except the spindle indexing connected to the 5i25-7i77. The machine runs on 3 axis, but I could not get the 4th axis to tune properly. If anyone has gotten the tool changer ladder program figured out, I would love to collaborate some to get mine going, too! Glad to see you guys are keeping the dream alive

Hi Mac,
I got mine going thanks to all the info on here. Not sure I did it the best way(I wasted an axis) but I took the servo and encoder from the ATC board, hooked it into the 4th axes controller(which had nothing connected to it) to make it A axis and I remapped m6 with a custom macro to do the tool change. It was all there, the only thing I had to do was add a prox for A axis home. Let me know if you need more info.