On what seems to be all larger prints (print time greater than an hour), both Z-axis stepper motors stop incrementing. My specs are:
TAZ4
PEI Bedplate
Upgrade Version2 Toolhead (Hex hotend)
Pronterface
It seemed to have occurred after installing the Version 2 toolhead along with the firmware upgrade. I suspected it was the firmware upgrade so I rolled back to the 2014 Q4 firmware (which I believe was still newer than the original firmware I had on the TAZ4 since I purchased it Sept 2014) and reinstalled the Budaschnozzle and old toolhead. The same problem occurred.
The same print worked just fine prior to the firmware and toolhead upgrade.
After it stops incrementing and I pause the print, I am able to manually change the Z-axis, so I do not believe it’s mechanical.
The Z-axis does not move at this level, so it extrudes and rubs against the top-most layer
I used a KITTAZ Rambo board.enclosure on my hardware and it seems to have worked fine.
I’m starting to think the .hex file that I used (and flashed with firmware) was the issue. The KITTAZ was running Marlin 2014Q3 RevB which was the same version I was attempting to revert back to with the hex file but was flashed directly from Arduino IDE. The 2015Q1 version was also a .hex file and also had the same problem.
I will try flashing tonight directly with Arduino IDE.
I had a Z-axis stepper motor issue this past week.
Did you check to see the z-axis is moving 1600 steps/mm? You can check this on the LCD screen in the control section.
Lastly, are the drivers over heating? This was my problem, I was extremely frustrated until I found out my fan was not plugged in…
https://forum.lulzbot.com/t/new-user-calibration-cube-issues/1521/1
… Just my thoughts
Well I think your thoughts saved me a lot more heartache. Sure enough, that was the problem 
I’ve been running without the RAMBO enclosure on for some time now and it seemed to work fine. But recently I started driving my bed plate hotter since it’s PEI and apparently runs at 110C. I’m guessing the enclosure just got hot enough where the drivers stopped working.
Thank you very much!
Awesome! Glad to hear it.
Yea, I never thought overheating drivers would cause so much grief, until I contacted support. If your Taz is in an enclosure I’m sure overheating can become an issue at high temps.
Glad your up and running
I really need to revive this 5yo topic because my 5yo machine is dealing with this exact issue and due to the change of ownership of Lulzbot, their support is nearly non-existent.
Is it possible that anyone else has experienced this issue and can share the solution that worked for them? I’ll break-down my experience so you can hopefully see why the previous solutions don’t seem to apply to my case.
I have a TAZ4 running the most recent version of the firmware 2014Q3. The firmware was manually selected and installed via CURA and worked great for months. While printing one cold winter night here in Colorado, I touched the frame of the printer and a small static shock caused the printer to freeze and reboot. When it rebooted, the settings for my steppers had reverted to the “stock” settings for steps. For my “Z” axis this means it set it to 1600steps. My Test/Acceptance record that came with the printer, and the setting that has been set since I got the printer has been 400steps.
I proceeded to put the settings back to what I understood to be correct, but now my machine only moves 25% of the input distance (A 10MM move yields 2.5MM of travel). Both Z motors turn in unison and at 400steps, they move smoothly with no drama. Obviously I tried increasing the steps 4X because it’s how I’d logically get back to full moment, but when set at 1600steps, the motors spin-up dramatically and lock up instantly causing all kinds of commotion and drama.
Lulzbot has been nearly 0% helpful only suggesting I re-install the firmware. Since sharing that solution was not successful, I have gotten zero response in more than 2 days.
My stepper board does not seem to be overheating. My fan is operating exactly as it should, and I have removed the cover from the board housing and am testing the Z axis movement with no heat in the nozzle or bed. There should be nothing taxing the board to the point it overheats.
Did something change in the firmware that requires the TAZ 4 to run with steppers set at 1600steps rather than the 400 listed in my Acceptance Record? Has anyone reduced the stepper ramp and speed to adjust for this and found that to be successful?
Thanks for checking out my zombie thread. I’d start another one, but this context fit so well.
After a late night of tinkering. I have actually found a resolution.
Given that I was only moving 25% of the distance, I started with trying to get to 100%. To do that I took the steps/mm back up to 16000. The issue at that point was the motors trying to spin-up so quickly that they just lock and grind. I concluded that it might be that the motors were going to full-chooch at the moment a command was sent, so I checked the V-Max speed setting in the “Motion” portion of my LCD controller. Sure enough, mine was set at 8 on a range of 1-8. I reduced the Z motor V-Max speed down to 3 and tested it. Everything worked fantastic, albeit a touch slowly. I stepped the Z motor speed back up a couple clicks to 6 and things are working exactly as I had hoped. Great quality. Quiet motors. I claim victory (and in 2020 that means you actually have to win!).
Thanks for the forum to externally process and for all the bits and nuggets people have left lying around that I was able to piece together into something… still haven’t heard back from Lulzbot. ¯¯_(ツ)_/¯¯
