Carvetight Spindle fell out

[Rob]

I was in the middle of a 6 hour carve when the tool holder dropped out of the spindle. I had just upgraded it and the entire Carvetight had less than 5 hours of carve time on it. I talked with Carvewright support and they said they had never heard of that before and that likely the z-motor had an error and caused the bit to jam, resulting in the tool holder becoming dislodged. Their solution - another Carvtight, a replacement z-motor, and a new ribbon cable.

I tried to reinstall the tool holder and was able to press it mostly back in place - to the point of engaging the drive cable. I suspect that if I had a way of pressing it back into place that I could make the Carvetight operational again. It almost seems that the tool holder diameter is out of spec, allowing it to fall out of the spindle. If it were pressed in correctly and tightly, it would not have fell out. There was no evidence of the tool getting jammed nor was there damage to the 1/32 bit.

Since the z-motor has never give me a problem before and there really isn't that many total hours on the entire machine, I wanted to ask this group -- does it seem reasonable that the z-motor has gone bad? Does anyone know a way to test the motor?

Thanks for any suggestions!

Rob

[fwharris]

If you had no indication of the Z motor stalling and the bit jamming like they said I would not think that was your issue. Could you post a picture of your problem?

[Rob]

I walked away from the carving for about 10 minutes.... of course that is when it happened. When I returned I had an axis error on the machine and the part was out. I should have taken a picture, but after posting I decided to see if I could press them back together. I froze the tool holder in the freezer and then with my vice and a couple of pieces of wood, I applied a bit of pressure and they slid back together. When I turn the tool holder in the bearing, there is a bit of roughness like the drive cable is still attached. Maybe that is normal.

[bergerud]

Did you take off the top hat? There is a circlip which clips onto the top of the spindle. This clip must have come off for the spindle to have fallen out. If you do not reinstall the circlip, the spindle will fall out again.

It could be that the circlip was not initially installed correctly (or at all) when the spindle was installed in the truck.

[Mugsowner]

What you are feeling could be a bad bearing. The spindle should spin freely and smooth. I could see the vibration of a bad bearing at 25000rpm causing this to happen.

[Rob]

The top hat and clip are in place, but I am becoming very suspicious that the bearing is bad. I am going to try to use it this weekend and see what happens. If it falls out again, hopefully I can get to the bearing fairly easily and see if I can replace it. I also wonder if the slight taper to the tool holder is not machined correctly which is allowing it some room to slip. Something is clearly wrong with the manufacturing quality. I am now convinced more than ever that it is not the z-motor or ribbon cable, and with only 5 hours max on the Carvetight, it cannot be worn out <smile>. However, since I have had the Carvetight for longer than 30 days, it is out of warranty.

I'll report back if there are any problems this weekend. Thanks everyone for your help!

[Rob]

Well guys, it did it again. This time I have better pictures. Personally, I am convinced that there is a quality control issue with this. I think there is a ring missing from the top of the tool holder and there is no evidence to suggest one was ever there. BUT, I know you guys know much more than I do. Thoughts would be greatly appreciated!!!8444084441844398444284437

[fwharris]

On picture 1033, the last one, you will see a slot/groove at the end of the shaft. The slot is for a C clip ring that keeps/holds the spindle shaft in the assembly. The end of the shaft and slot should be just above the top spindle bearing.

[bergerud]

The circlip as Floyd says (what I was referring to in the earlier post) must have been missing. Further, the bottom bearing should be firmly pressed onto the spindle. I think you need to send the upgrade parts back to LHR.

[Ducky63]

Well I have a different problem!!! instead of the hole spindle falling out I'm having problems with the 1/16" bit just falls out of the spindle while it is caving. i have even put in a new bit and it falls out. Does anybody know what I need to do to keep the bit in??? I should say that it is on my B model and the carve tight was one of the first ones that came out. Thank you for your help!!!!

[bergerud]

For some reason, the "cam" must not be tightening up against the bit adapter. With no bit and the bolt tightened, use a mirror to look into the hole. Does the cam protrude into the hole? Maybe take out the bolt and cam and have a look for damage. It is a simple mechanism, there could be a foreign object behind the cam?

[fwharris]

Probably needs to be cleaned and lubed. Remove the parts as Dan suggested to clean them and lube with 3-1 oil. Also clean the inside of the chuck and lube.

[Ducky63]

Thank you for the replyes!!! I have to try that this afternoon, Thank you!!!