Z Truck failed

[bjbethke]

My machine was just returned on 25-Sep-08, I noticed damage to the right slide plate lock when it was returned. Today when I was half way through a six hour carving a set screw sheared off the carving bit, found a bad QC and a crack in the Z Truck, upper right bearing. I think the carving may be OK, when I redo the carving. I will send a PDF with photos to LHR this evening and give them a call in the morning. I think the damage to the QC happened when LHR ran the bit into the Slide Plate. Hope I don’t have to send the machine back again. There was no damage to the Slide plate when I sent in my CW on 17-Sep-08

[Digitalwoodshop]

The BB damage on the bit holder bothers me. Was there any damage to the bit holder when you started carving. Or did the BB damage happen after the set screw broke? I would think it was the other way around. A bad QC causing the bit to become so loose that it was flipping all around until a failure happened.

I believe the bit holder was the source of the start of the problem. Or it could have been the cracked Z that cause the stress on the QC to the failure point..... Bet it made a racket as it died......

Bet the Drive Cable is damaged too.... Or will fail soon.

AL

[Ike]

The BB damage on the bit holder bothers me. Was there any damage to the bit holder when you started carving. Or did the BB damage happen after the set screw broke? I would think it was the other way around. A bad QC causing the bit to become so loose that it was flipping all around until a failure happened.

I believe the bit holder was the source of the start of the problem. Or it could have been the cracked Z that cause the stress on the QC to the failure point..... Bet it made a racket as it died......

Bet the Drive Cable is damaged too.... Or will fail soon.

AL

Al, I see what you mean, do you think the set screw for the bit adapter was loose? Then it started wobbling and caused the top bb damage? Or do you think there was damaged to adapter that cause the set screw to break?

bj, I hope you call LHR and let them know there was damage to your machine when it returned?

That is my biggest concerns before carving, one the set screws are tight and that when I change bits it is properly seated. Had one not seat and it just dropped out when it checked the bit. Could have been far worst!

Makes me want to double check the QC

Ike

[bjbethke]

There was no damage to the bit or adapter when I installed it. The MPC has a cut out, and the cut bit and the carving bit both installed OK no movement. It carved OK for over two hours. I checked the bit for movement twice when I pushed the saw dust off the leadge. I stopped the carving when the sound changed. The bit then had a wobble, then found the damage.

[Digitalwoodshop]

There was no damage to the bit or adapter when I installed it. The MPC has a cut out, and the cut bit and the carving bit both installed OK no movement. It carved OK for over two hours. I checked the bit for movement twice when I pushed the saw dust off the leadge. I stopped the carving when the sound changed. The bit then had a wobble, then found the damage.


Well, you were doing all the right things I would have suggested.... Check the holder before installing it... Checking the bit for movement during a long carve.... The Fatal failure is hard to analyze. If the set screw broke it would cause it.

It's the Chicken first or the Egg first.... I leave it to LHR to do the failure analysis on this one.

AL

[bjbethke]

I called LHR today. They will send me the replacment parts, there was a$40.00 core charge, which will be returned when they receive the old Z truck. Not sure about the bit yet, but I do have a spare. At least I do not have to send the machine back. I will have to pay shipping to return the old parts, but that's not too bad.

Thanks everyone.