Z Axis stall nightmares

Ok, as I stated before I have had the CW for about a year or so and I just got into the double digit hours for carve time. Here is what happened:

I purchased the CW and carved 1 test item.... just to see the machine work. Something small, no big deal.

After playing with the software and getting a design that I really liked, I got everything loaded up into the machine a proceeded to carve. During this carve I received one "Z Axis stall" error message. I reset the job (about 25% complete) and restarted the machine. No more problems...

My 3rd carve was to be the same item as before, I wanted to see design repeatability on different types of wood, the first piece was pine, this was to be red oak. I got everything loaded up and started the carve. This time all hell broke loose: The machine jammed the bit to the hilt into the wood, almost dead center of the piece, and started cutting at darn near warp speed (through 1.5 inch red oak) along the Y axis. The bit broke and smoke was coming from the machine. I cleaned everything up, let her cool, checked the design again, got another piece of wood and started over again.

This time it was error after error, all of them Z Axis stall. So I closed up shop for a while. I never got around to sending it in for warranty repair, life has a way of distracting you sometimes. So here I am, brand new workshop $2k on a machine, its out of warranty, and broke... time to break out the duct tape.

I found the manual on the CW site on how to remove the "Z Pack" and followed the instructions. I figured the best place to start was there since it was the culprit for all the errors. As I started to work, I found that I could not turn the 2 cammed screws.

There was a note about these in the guide that said that if they could not be turned that you should drill them out as they may be cemented in.... permanently. I tried the hair dryer trick thinking it may just be LockTite, but no.... those screws are in there forever. Not trusting my screw drilling skills, nor my ability to replace them, and considering the fact that I don't have a "Tap and Die" set handy anymore I had to figure out another way.

The manual also stated that the 2 nuts on the backside could be turned with a 12mm wrench, the only problem is that the wrench needs to be about 1/4 the thickness of a regular wrench to fit between all the parts. If you find one that fits in there do me two favors, let me know where you got it, and keep a hold of the one you have! Well the two options that the company gives are out, time to pull some MacGyver Magic out of the hat.

I noticed that the manual said that the 2 rails the Z Pack "floats" on are free floating. I started looking at how they were held in place and figured that if I drilled the top of the aluminum housing for the rail on the right side that I could push it out and not do too much damage to the housing.


Drilling was fairly easy, I made sure to tape off the area to prevent filings from contaminating the rest of the machine. After I drilled to the top of the rail, a few light taps to the bottom of the rail and it popped right out.


After removing the entire assembly I found my culprit: 2 friggin small screws, the two screws that hold the Z Pack to the belt had worked themselves loose. One had disappeared entirely, and the other was holding on by two threads.


I added some BLUE LockTite and replaced the old screws. I used the BLUE LockTite instead of the RED so that I could still remove the screws in the future if needed.

I have put a couple of more hours on the machine and have not had a problem yet. I am hoping that this works.... will post updates and let you all know how it goes.

Dudbuster,

Holy cow! This is some story! Thanks for sharing. Has anyone else had a problem like this?

By the way, I would think that this would be something that LHR could at least attempt to help you out with under some kind of good customer service repair etc, etc. Give it a try. They've been a big help to other folks with problems out of warranty.

Good luck!

I was thinking about that, but I don't like to have other people fix my mistakes. I messed up when I didn't send in in during the warranty period... plus these are they exact type of problems/things my brain lives for.

Dudbuster,

Not sure how I missed your post! From the sound and look of things you are not afraid to find out how things work. Great job with posting your steps along with great pictures.

I do not think I would have thought about your way to get the z truck off. Luckily I was able to get my adjustable bearings loose. I had to grind down a wrench for the bearings.

On mine I could not get the screws to loosen either. Even started to strip out the head. But I could turn the bearings with the wrench. After I got the truck off I was able to take the bearings off and get the screws out. I got some hex head replacement screws at Ace Hardware. The head is just a little bit bigger so they only work for the bottom bearings though.

Your loose screws on the drive belt was probably the result of the bit taking a dive into the board. too much torque on the head. the loose screws could have also been part of your z stall errors too.

Your bit taking a dive most likely was from the bit not touching the bit plate during the homing sequence routine. If the bit does not land on the full flat part of the plate it will register a false height/length for the bit. Most often result is the bit taking a dive into the board. If the bit does not touch the plate at all it will go back to the install bit prompt Commonly called the "load bit loop". Something to watch for during the start up process. I know I got burned a couple of times so I always pay close attention to it.

Again, great job and glad you are back to carving!!

Dudbuster,

What a story! Am sure glad you got this fixed and I certainly understand your desires to fix things yourself.

I'm more than just a little curious if maybe vibration had anything to do with this? Did this happen with the Rock Chuck installed?

DudBuster wrote:The manual also stated that the 2 nuts on the backside could be turned with a 12mm wrench, the only problem is that the wrench needs to be about 1/4 the thickness of a regular wrench to fit between all the parts. If you find one that fits in there do me two favors, let me know where you got it, and keep a hold of the one you have! Well the two options that the company gives are out, time to pull some MacGyver Magic out of the hat.

Sorry I missed this also.

I have one and found it at a bicycle repair shop. They have the 12mm wrench in just the right thickness. If they dont have a spare they are willing to sell to you they will show you where you can order one. The guy I talked to had a spare and sold it to me for 8bucks.

I started stripping the screws and decided to stop before I did some permanent damage. I thought about drilling the screws out and replacing them, but to my knowledge the screw dimensions are not listed anywhere. I didn't want to use a bit whose diameter was too large, nor did I want to drill too deep. That left me with the 12mm wrench option I looked everywhere (except the bicycle shop, thanks for that tip!!! Going there Monday first thing.) and tried a few tricks to "manufacture" my own wrench, but no joy to be found. I was standing there smoking a cigarette and working on the second half of a six pack when the "nuclear option" popped into my head. I figured "What the hell? It wouldn't be the first time I did something really stupid."

I will start paying closer attention to the start up sequence and EVERYTHING that goes into it. I can see myself becoming complacent with that portion of the project pretty easily and need to start learning the good habits and taking a few seconds to do it right the first time.

I don't have the Rock installed (Yet!!!) but am planning on getting in touch with Ron in a few weeks and purchasing it. I would have to assume that my problems started like fwharris stated: the bit not touching on the homing sequence. This would cause the machine to think that the bit was a different length than it actually is. Another logical assumption would be that it wouldn't have made a difference if the Rock or Factory QC were installed at the time of the homing malfunction... something that everyone needs to be aware of I guess.

Again thanks for the tips and assists, you guys are awesome!

My machine did the same thing as your story. It started with the lower left bearing screw coming loose and the z truck went for the smoke test and failed. I was sent the replacement parts by the factory but after changing out the z truck a couple of times the factory said to send it back. Well, they did their magic on the machine and it works GREAT now. I've done two 10 hour carves and they look wonderful. I'm convinced that this machine is quite sophisticated and needs LOT"S of T.L.C. This means clean-clean-clean. I had some alignment difficulties and a good 5 min cleaning solved it. BINGO- it works great. It's kind of like owning a model T. If you want to drive it you must be able to work on it. Any way, after 5 or so expolding QC I replaced it with the Rock and most of my inconsistancies are gone. I am excited to try F W Harriss DC collection nozzle. It will be all together then. Ol' Dad

Everyone, my Z-Axis Stall errors and the following post are related: Click Me Weird Lines in Project Just goes to show how one small detail, like not putting Loc Tite on a screw at the factory can cause premature balding..... and liver damage.

Dudbuster,

Great update on the root cause!

I also have had Z truck difficulties. I began with the bottom left machine screw backing itself out during a carve session. The bit dove into the work piece and broke. The factory guys sent me a new Z truck AND they included a thin 12mm wrench. When they sent me another truck and another truck, they all came with a new thin wrench. Now I have a couple of them. I'd like to trade a thin bearing wrench for a square drive that fits the flex-shaft female receiver on top or bottom of the Z truck. I have made my own after the one broke that came with my Rock chuck. I'm SOOOO happy with the Rock. The square drive I'm looking for is one that the factory uses. At one time they offered to sell me one, which I accepted, but they didn't send it to me. Fancy that!!! I understand that LHR holds the patent on the QC so naturally they push them. I would be very impressed with the company if they would offer the Rock as an option. The QC does seem to be a weak link, as is the dust collection. I found out that five mins. of cleaning will change the machines behavior. These two items would make a great improvement for an already good machine. And believe me I have had many warm to heated discussions with the folks on the other end of the phone. Any takers for the trade, one factory flat wrench for one factory square drive. Have wrench, will trade. Thanks again for all the good help. Ol' Dad