My lab has a Mazak SQT-15MS (circa 1991) running T32 control. Despite her age, she runs well. However, I cannot seem to cut threads with normal spindle rotation. Using the Mazatrol threading process, the machine will traverse to the starting point of the cut, and just sit there with the spindle spinning, indefinitely. No alarms are thrown, and it appears to have a G32 in the register. However, if you reverse the spindle direction (via the tool data menu), the program will run. Unfortunately, this means that I can only cut left-hand threads.
With the spindle spinning in reverse, I can cut in Z+ or Z-, but the spindle HAS TO BE spinning in reverse. I could flip the tool upside down and move in Z+ with reverse spindle to cut right-hand threads, but then the tool accelerates through the part, and the threads near the shoulder have the incorrect pitch.
I checked U38 (accel distance clamp), and it seems fine. I've perused the other user parameters associated with threading, and everything seems to make sense. Like I said, she'll cut threads with reverse spindle, no problem. I suspect that one of the parameters not listed in the manual is wonky. Our back-up battery is shot, and we've had all the parameters cleared when we've lost power. We have a copy of the full parameters list from Mazak, but there's no explanation of what any of the unlisted parameters do. There are a few unlisted user parameters that don't match up with the list we have, but I don't want to start changing things without knowing what'll happen (especially since a few of the parameters on our list are scribbled out with three or four different values written next to them).
I also wrote some basic g-code using a straight G32 and not much else, and the program would run fine with an M04, but not an M03.
No amount of searching the internet has proven helpful. Any help would be appreciated.
-Mike
