Have you been able to repeat the bug or has it been inconsistent?
So far Iāve only had it happen that one time.
Did you carve the file that had the issue more than once?
I carved the exact same run 2 times and only one of the times had the issue. I carved the same file with some changes 2 more times and didnāt have the issue again.
Is it possible that at the end of that one-time, the bit may have slipped, correct?
That was my first thought since when using the dremel spindel, I had the bit come loose several times. But I checked and the bit was still secure and right where it should be. I really love the ER11 collet system, it works great.
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Just curious. Did the Z move get completely skipped or did it move part way up before traversing? Secondly, were you there when the problem occurred? If so, did the move sound normal?
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The z did not retract at all. When the end mill started digging through a half inch of pine at fast traverse speed, it did not sound at all normal (scared the crap out of me). It took me a couple of seconds to recover and hit the estop.
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It may not be the bit and I agree the ER11 system is pretty darn good. I take a permanent marker and draw a thin band on my bits and match up the line when I install bits so I can barely see the line. Then if the line disappears or a space appears between the ER11 collet and the bit I can see itā¦ I have been amazed just how often this occurs even with all care taken. It seems the longer jobs are prone to this very often, so much so I occasionally pause a job and re-tighten. I think itās a combination of heat, humidity and oil from the wood. Recently I started scuffing my bit shafts sanding lightly with 320 grit paper. It has really helped. I only share this with you because I have experienced the depressed anger associated with watching a long job end this way. Cheers PS. Also dust and chips in the groove could contribute.
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Thanks Don, that is a good tip. I have been a bit reluctant to test what happens when the pause button is pressed. Good to know that is a workable option.
I sprayed some dry PTFE on the ACME rod and it works great, I thought it was smooth before but now it is even better.
Plus it is great for squeaky/sticky doors. Great suggestion.
I think Iām having the same problem. It seems that the longer the cut (or alternatively, how long Iāve been using the machine) the more likely this problem (z axis drop + not retracting) happens.
Iāve had three cuts so far that ācompletedā but then tried to plow through material due to the z axis not retracting. Once this happens and I stop the run and move the machine with Easel manually, the Z-axis motor makes an unusual whirring noise and rarely is able to actually move the z-axis (I ensured all the set screws were tight and I have threadlocker on the way).
Is it possible that the spindleās heat is affecting the delrin nut somehow?
I have a threaded rod instead of the ACME rod, so Iāll also try lubricating that.
Can you share your file? Iād love to run it on our machine to see if I can replicate the error and determine if it is in the same spot.
Do you have a fan?
Sure, hereās one of the cuts where I had this problem: gear
That being said, I doubt this is a problem anywhere else but my setup. A few more notes:
I think I was doing .08 in/pass when I was cutting that file, in .350in plywood. When I just did a cut a bit ago in .250in poplar, it was doing the .28 in/pass default. I left it alone for a few minutes with the power supply turned off, and when I came back the z-axis was working just fine. I also need to desperately go back and re-tension the y axis belt(s)ā¦ may be unrelated to this problem.
Itās also possible the nuts on the threaded rod arenāt set up quite optimally, I might go back and make sure thereās no wiggle between them.
Hey Zach -
I used loctite on both gears for the threaded rod and the z-axis stepper, but about ~12 minutes into this cut I ran into the z-axis issue again. Hereās the issue on video right after the problem occurred (the bit plunged way too far and I paused the cut in easel).
I donāt have a fan blowing on the stepper or the spindle.
Is it possible the v-wheels are too snug on the z-axis?
Hi @TheodoreHoff I am really sorry this happened. It is possible that the wheels were too tight on the Z and it skipped a step but Iām skeptical this is the case since it has happened to more than one person.
We ran a test Friday where we heated the Delrin nut and ran the machine hard for hours. We were not able to get it to skip a step.
The fact that you didnāt have a fan on the gshield is interesting because I have a hypothesis that if the stepper driver is over heating. When the driver over heats I think it is skipping. I canāt prove it yet and havenāt been able to repeat it. The issue is happening intermittently.
The fact that you donāt have a fan would support this hypothesis.
Some questions:
- Are you able to repeat the error?
- What software did you use to generate the g code and send it to the machine?
Oops, Iām sorry - I do have a fan on the gshield running full blastā¦ but now that I look at it, itās blowing out, not in! I flipped it around but the same thing happened.
As far as the questions go, this happens every cut so far (5 or so?) that runs over 12-15 minutes. Iām using easel for both the g-code generation and sending it to the x-carve.
Thanks for taking a look Zach - you guys are awesome (running tests just for me! good to know the delrin nut can handle the heat). Iām going to rebuild the z-axis everything and triple check the wiring, then try again.
That is interesting Zach, when I had the problem with the Z not retracting my fan was removed from the case.
Iām also having issues with my Z-axis right now. I will move fine for the most part in the lower end of the spectrum but when I try to raise the Z-axis more than about half way I get a lot of skipping. Iāve also had an issue with the Z-axis not trying to retract after I stopped the carve. This caused the rapid move home to nearly snap the bit but instead it just got stuck.
I ran the Delrin nut through the rod about 30 times with a power drill before I put it on. Could it need more? My z-axis v-wheels are extremely loose because it seems like anything every remotely tight causes it to seize movement on the z-axis.
Anyone know whatās going on with this?
Mine did that, and, I just needed to adjust the current pot. Itās still sticky towards the top, but, Iāve not needed to go that high yet. Inventables sent me a new nut and threaded rod just in case.