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View Full Version : Sudden plunge, broken Z-drive gear



Jeff_Birt
01-06-2007, 01:16 PM
I had a problem with my machine last weekend. It suddenly plunged into the stock and then kept right on carving (see photo). I found that the Z-axis drive had lost a tooth on the counter gear. I got a hold of CarveWright on Wednesday and found out that they had gotten some bad encoders from Sharp that missed counts ( I got on e of the first batch of machines from Sears). They are sending me out a new Z drive assembly so I hope to be up and running next week; just wanted to add to the troubleshooting knowledge base in case someone else has the same problem.

One another subject, I overlaid text on a pattern from the built in library. It looked fine in Designer but some clipping occurred when it was carved. This is probably due to the greater height of the letter vs. the pattern. I could not seem to find a way to avoid it and thought maybe someone out there might.

Jeff_Birt
01-08-2007, 06:53 PM
Just an update. Got the new Z-Axis motor assembly from CW today and installed it this evening. I made a very simple 5-min test carving and now am about 30% through an 1 hour 17 min carving. It's alive :lol:

Just to be clear, CW offerd to pay for shipping to-from their facility and fix it themselves but I offerd to do it myself (as I used to work on really big CNC shape cutters).

I was not happy to have a problem so soon but CW stepped up to the plate and took care of it.

:arrow: EDIT: Holy crap! The piece I was carving just got finished a while ago and WOW :o . I guess my Z-Axis encoder had been losing counts all along as this carving was fantastic. If you look in the picture above you can just make out some slight 'scratchs' on the wavey background surface. This new carving is dead smooth (other than a few miner fuzzies), no scratchs.

Jeff_Birt
01-13-2007, 10:50 PM
Just an update on the broken gear and 'scratcning' issue I mentioned above. I had a home sensor error tonight and using the sensor check feature of the machine (a very nice feature) I was able to find that the home sensor was stuck on, and would go off when I wiggled it. I removed the Z truck and found the sensor had broken. I fixed the sensor, reassembled, did not get the lower bearing adjusted right and the Z-truck became quite loose in the middle of a carving. I stopped, properly adjusted the bearings to remove play and all was well.

The intersting thing was the the initial symptoms of the loose Z-truck tonight were those same small scratches in the carving and I noticed when my Z-Axis took the sudden plunge before that the Z-home flag looked a bit askew.

This leads me to the following conclusion:
My initial problem was a loose Z-truck. At some point the home sensor caught on the Z-home flag bending the flag, breaking (or cracking) the gear, and breaking the home sensor.

So, be sure to wiggle your Z and Y trucks to check to loosness on a regular basis (it even says so in the manual). I wonder if CW had a how to written up on the proper way to adjust the bearing?

Azbear
02-17-2007, 08:48 PM
After checking and double checking the "fit" and "click" of the bit in the chuck, I proceeded to start my 1st carving. After only about 4 passes, bit took a plunge and got stuck in project board. I freaked and hit the stop button pronto. I again repeated the proper check and started again. Same thing happened and now a few pieces of metal are laying on my project board. What have I done?
I have read the forum for some time and double and triple checked the "fit". As it is Saturday night here in the desert, I'll have to ponder what I over looked, until CW opens it doors Monday morning. Sure wish there could be an after hours hotline.

rmacke
02-17-2007, 09:20 PM
This is just my opnion-- feel around the inside of the chuck (were you insert the bit holder) and see if you feel any sharp edges. To me it looks like the bit holder wasn't lock tight into chuck and fell out and broke off a piece of the collett.
rmacke

Azbear
02-17-2007, 10:00 PM
rmacke,

Yes, something sharp up in the chuck. As I mentioned, I heard and felt the "click" when inserting the bit.

:cry:

Ron Baird
02-17-2007, 10:55 PM
It lools like the bit was not locked into the chuck. The way the bit is stuck in the board is the evidence. The bit adapter may have one of the set screws broken off. When you insert the bit in the chuck you should always give it a tug down to be sure it is locked in. You may have to change the chuck if it has much damage to it.

Jeff_Birt
02-17-2007, 11:18 PM
azbear, do you mean the Z-axis plunged or that the bit fell out?

Azbear
02-18-2007, 07:43 AM
After I slid the bit adapter into the chuck I know I heard and felt the "click". I also forgot to mention that I did check to make sure the bit was seated by using the bit tool as well when tugging downward. I swear I saw nothing move. I just don't know. I'm afraid to run another test until I speak with theCW folks.