We have a 5 yr old VF-3...15K spindle with a side-mount mag.

In the 5 yrs since we bought it, it's gone through a couple spindle-drive belts, a couple of toolchange arm wipers, and a set of x-axis way-covers.

None of that was as big a deal as what happened yesterday morning.

Ran #2020 spindle warm-up program and then loaded a set of tools for the day's job. 6 tools loaded normally, and then we began to run the first part cycle of the day. The machine loaded & ran the first 3 tools as normal and then, as it was loading t # 4, it blew up...literally.

There was a very loud BANG followed a heartbeat later by a second bang...and then the tool fell out of the spindle and hit the table. Roxanne had her red-light on immediately; the toolchange arm was out of register and the spindle was in UNCLAMP. Thankfully the doors were closed, and thankfully the spindle didn't have a chance to start up.

The first order of business was to get the TCA back to it's origin so we ran the recovery and it worked just fine...but the spindle would not get out of the UNCLAMP alarm no matter what we did. Putting the control in Handle/Jog allowed us to push the button on the Z-head...it worked, but the usual spindle-air blast sounded weak and hollow, and the alarm would not clear. So, we removed the front cover of the Z-head, and what we found was a pile of shrapnel. The spring-loaded plunger on top of the TRP had snapped clean through, the fat spring was laying in the back of the head enclosure, and the TPR itself was cocked up at an angle with the left side higher than the right. Two sheared bolts were laying inside, and the big fat o-ring that you should not see (because it's inside the TRP) was ripped in two and completely exposed. The TRP itself was just laying there, loosely held down by the two remaining screws. Upon removal of those two screws, we found them to be stretched & bent. We removed the TRP assembly and all the loose pcs and found that the drawbar was not damaged as far as we could see so we're hoping it's okay. Called Haas and they were incredulous over the phone...don't know if that's just a sales/service tactic to sound so surprised or if this really is a genuine "new- one" on them.

Just wondering if this has ever happened to anyone else's Haas? We have 6 CNCs but only one Haas...the rest are Hardinges and old Leadwells. They all continued to run just fine and nothing else in the plant was affected either so we've come to the conclusion that it wasn't a freak air-pressure surge.

The HFO techs are coming out on Friday with a new assembly...I'll post a few pics if I can.


Rob.