Anyone ever have a TRP explode?

[MauserBob]

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.

[ToyMaker94566]

What's a "TRP"...? Whats's a "TCA"...?


So you broke a what...?

[MauserBob]

Sorry.

TRP = Tool release piston

TCA = tool-changer arm.


Didn't feel like typing all that out multiple times, and the Haas techs used those acronyms over the phone so I assumed folks here would know 'em for what they were. My bad.


Rob.

[haastec]

Been working on these for 12+ years and have never seen one as you described.

Hopefully nothing other than the TRP components trashed and you are back running soon.

[Haas__man]

I have also worked on these machines for a number of years - and i havn't seen this exact problem either. I have sheared the head off one of those TRP bolts though when I was re-fitting one. I put it down to it being a weak bolt to start with. I would say that either you had weak bolts to start with - or maybe the bolts weren't fully tightened. Has the TRP been removed recently for any reason? You said you had new spindle belts? was that recent? If the bolts were loose - even slightly, then everytime the tool is unclamped the bolt head is shocked - and therefore stretched and snapped. The two that were bent were bent because the other two had already snapped.
Hope you get it repaired soon.

[DaOne]

Whats the air pressure at the TRP? Maybe the regulator failed. Seen shop air at some crazy high PSI but never seen a TRP grenade.

[MauserBob]

The last belt replacement was over a year ago, and the TRP assembly has never been touched by anyone here...I can't say with 100% certainty but I'm reasonably sure no HFO techs ever messed with it either.As far as the PSI at the regulator, I don't honestly know what it was at the time and won't know until the tech gets here Friday due to the fact that the hoses are all disconnected. I will say that after the blow-up, air pressure seemed "normal"...plant air PSI is 140 max, and off the top of my head I think we have it regulated down to 100 for the Haas but I'm not 100% sure of that.

[MauserBob]

Pics...

[haastec]

At least the solenoid fittings look useable.

[MauserBob]

Well, we caught a break today; the HFO tech came earlier than we expected. He showed up @ 1 pm today and had it up and running by 3 pm. Echoed what several of you have said...he'd neither seen nor even heard of this happening before. Go figure...

Meanwhile, I double checked the regulator PSI and it's set to 90 which the tech says is right where it should be. So...no answer to the mystery. The tech theorized that one bolt was either pre-cracked ( to order ) or just fatigued from use...and when one let go, the hold-down power on that side was decreased by half and caused the second bolt to let go too. Just a theory...

Rob.

[omy005]

We have had a few of these bolts break on our VF2 SS machines.

Andrew.