Live tool drive failures

[Ewood42]

The company I work for purchased a new Haas ST35 3 years ago, and have had to rebuild the live tool (BMT) drive system numerous times. There was a pretty severe crash early on with it, but it had a complete rebuild all the way back to the torque tube. Has anyone had repeat problems with these?

 

Looking back through maintenance logs, it looks like they tried to just replace the right angle gearbox first; still sounded bad so they replaced the torque tube; then reassembled but had debris under the turret preventing proper alignment and tried to test it. Would trying to run with improper turret alignment damage the torque tube? It does not appear to have been replaced again, and we've had issues with noise/excessive heating at 4k rpm ever since.

[#Rekd™]

Running them without coolant can cause overheating and most of them have a duty cycle I believe.

[Ewood42]

On 6/1/2021 at 9:00 AM, #Rekd™ said:

Running them without coolant can cause overheating and most of them have a duty cycle I believe.

Duty cycle is supposed to be 100% at 4500 rpm or less, but ours heats up pretty rapidly at 4k. First thing I looked at. Duty cycle is only 15% at max rpm of 6k.

 

Though I did find out there have been a couple instances of operators loading tooling blocks and trying to tighten them down without backing off the jack screws first, so probably a little of column A and a little of column B.