Cnc knee mill

[Yomama]

This is an old jetmatic knee mill from the 80s. It weighs over 2 tons I think. When I purchased the machine, it was completely stock, with the old microteck control system. It read g code off of a casset tape player. It came with nema 42 steppers with hall effect style encoders on the motors. I completely gutted about 200 lbs of electronics out of the cabinets and replaced them with three hybrid stepper drivers from leadshine. The encoders were swapped out for 1000 line disc hubs and readers from US digital. There is a 5 hp rotary phase converter in one of the cabinets.  The new drivers and a pmdx 422 board in the other cabinet. The swing arm will have a control box with a 22" touchscreen mounted on it soon. So far, with great help from the pmdx forum, the machine is completely operational. Just a little more add-ons and it will be done.

I will follow up when finished

[AlvaroDul]

Amazing Yomama, any updates?

[Dave Clarke]

Hello,
I found your post from 2016 about your jetmatic mill conversation. I’m working on converting one just like it. Any advice you can give me now that you have done a conversation on one of these machines? I’m looking to make this as seamless as possible. Any recommendations are appreciated.
Thanks,
Dave C

[Yomama]

Sorry for such a late response.

I used the machine a lot when i finished it, but never powered it back up after i moved like 2 years ago. I did put a pendant on it, which is absolutely a big plus. I even homemade a little 4th axis for it and ran a few test parts. It worked.

Advice. Make sure your communication lines are shielded and dont route anywhere near anything high voltage. The board will drop communication. Other than that, i would plug my laptop in, hide it away from any chips, and then use the touch screen. Worked pretty well. Was def nice having a big screen.

As for the mill itself, i was happy with it. Ran it for long spells unattended. It would home and limit at overtravel no problem. This was a great mill to do a mach 4 pmdx mod to. The old wires were all stiff and had to be replaced, but it was pretty simple to do. I just measured the steps per inch of travel and it cut to tolerance.