I recently started having this problem on my 1998 SQT 250 MS (T Plus) where sometimes when moving the X axis for the first time after startup it throws an overload alarm - even when moving as slowly as possible. Sometimes it does it before the machine even turns on completely, sometimes it doesn't do it at all.
Brake seems to work fine - you can unplug it from the board and hear it click and you can also see the turret drop a bit before the brake catches it when overload is triggered.
Sometimes you can hear the motor grumbling like it's struggling or maybe doing very small corrections. If you can slowly move the axis and get past this stage the machine then works fine all day. The load meter doesn't increase gradually before this happens. You can move in 0.001 mm increments and hit a spot where the motor just starts doing it and the load meter starts jumping all over the place, then you move by 0.001 mm and it stops. At rest, it usually shows 55%, after an overload and restart it goes to 33% so that's suspicious. It used to always be at around 55% (is that a bit high?).
After the overload is triggered the X axis position sometimes (I promise this is the last 'sometimes'
) jumps by about 1mm randomly - that doesn't look normal either.
A Mazak tech came out, swapped X and Z drives - still the same. He's coming back next week and I'd like to find some suggestions as to what may be causing this. The most frustrating part is that it only does it after the fist startup and even then not every time. Any suggestions will be greatly appreciated.
Brake seems to work fine - you can unplug it from the board and hear it click and you can also see the turret drop a bit before the brake catches it when overload is triggered.
Sometimes you can hear the motor grumbling like it's struggling or maybe doing very small corrections. If you can slowly move the axis and get past this stage the machine then works fine all day. The load meter doesn't increase gradually before this happens. You can move in 0.001 mm increments and hit a spot where the motor just starts doing it and the load meter starts jumping all over the place, then you move by 0.001 mm and it stops. At rest, it usually shows 55%, after an overload and restart it goes to 33% so that's suspicious. It used to always be at around 55% (is that a bit high?).
After the overload is triggered the X axis position sometimes (I promise this is the last 'sometimes'
) jumps by about 1mm randomly - that doesn't look normal either.A Mazak tech came out, swapped X and Z drives - still the same. He's coming back next week and I'd like to find some suggestions as to what may be causing this. The most frustrating part is that it only does it after the fist startup and even then not every time. Any suggestions will be greatly appreciated.
Last edited:
. Thanks for the diagnostics tip, I'll add it to my troubleshooting folder, on a machine this old I may need it again soon