When turning off the spindle, the braking system is no longer working. I replaced the re-gen resistor as that was what FADALCNC.com told me would fix it. Nope.
When turning off, it free spins, then lurches like you hit the brakes, but only for a half second, then free spins some more and lurches slower, and does that about 3-4 times and eventually free spins to a stop.
It's a DC, 1993 machine with an Advanced Motion Controls spindle driver.
Look for a inv-30 from fadal cnc it should fix the issue. One thing to note though is fadal cnc nor glentek will help you installing it but it’s really simple. Most of the techs didn’t even know such a thing exists and some of them couldn’t even understand how a glentek board would work on a amc drive. But I tried it and after the first one not working at all the second one worked perfectly.