Auto Level Fail

A forum dedicated to the stock LulzBot Mini 3D Printer
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u2fletch
Posts: 2
Joined: Mon Jan 01, 2018 5:27 am

Auto Level Fail

Post by u2fletch » Mon Jan 01, 2018 5:41 am

New Lulzbot Mini which had issue of when attempting a followup (non cold start) print, the nozzle would attempt to wipe about 1cm above the pad. Then the nozzle would crash on each washer, noticeably deflecting the bed. However, it would pass the autolevel routine and start printing.

The first layer would not print since the nozzle was dragging on the PEI and no material could extrude. Once I saw this behavior, I would watch the machine like a hawk during print start and if I saw it "air wiping", I would abort the print and shut down the machine and reload filament(since it retracted 30mm before the wipe).

Contacted support and they recommended upgrade Cura 2.6.63 (which was not released or available yet) and upgrade firmware and clear cache. A week later I was able to get new Cura and do this.

Now the wiipe function appears to work okay, but the nozzle does not go as deep into the cleaning pad as before. The nozzle touches the rear left washer fine, the front left washer fine, then lowers towards washer number 3 (front right) but aborts before touching the washer. Looks like it gets about 1mm away before aborting. It then attempts a nozzle wipe, but the wipe is useless since it is a couple mm above the pad. two more attempts and the autolevel procedure fails.

Any ideas or thoughts?

In the meantime I will perform another firmware update and see if there is any change in behavior.

Jeff

u2fletch
Posts: 2
Joined: Mon Jan 01, 2018 5:27 am

Re: Auto Level Fail

Post by u2fletch » Mon Jan 01, 2018 6:17 am

After more perusing of the forum I found the answer:

Post #6 in this thread: viewtopic.php?f=43&t=6426

The X-axis carriage got misaligned at some point and I needed to manually tweak one of the lead screws to get it back square.

Problem solved!

Thanks forum!

Jeff

shill66
Posts: 4
Joined: Tue Jan 02, 2018 10:11 am

Re: Auto Level Fail

Post by shill66 » Tue Jan 02, 2018 10:39 am

This is very interesting to me because what you describe is EXACTLY the same problem my Mini has since updating Cura a few days ago. During bed level testing, it taps the left rear washer, it taps the left front washer, then on the right front washer it retracts too soon, goes over to the cleaning pad but does its wipe pass about 2mm above and behind the actual pad, in air. It repeats that twice then stops and gives up.

I've never had a bed level problem before and nothing has moved. The problem in troubleshooting is that at the same time I updated Cura, I also updated firmware AND installed a Flexystruder. So I can't narrow it down to one specific thing causing the problem. I will investigate your solution (and post again after I have done so, at least 10 hours from now) but the fact that my printer was behaving exactly the same as yours under very similar upgrade circumstances makes me very suspicious that your solution may have been coincidental, and there could be something else causing this, in either the firmware or Cura.

shill66
Posts: 4
Joined: Tue Jan 02, 2018 10:11 am

Re: Auto Level Fail

Post by shill66 » Tue Jan 02, 2018 11:46 pm

Well, I was wrong... my x-axis too wasn't parallel to the bed, and adjusting the z-axis fixed the problem, just as it did for you.

ztatic
Posts: 17
Joined: Mon Jan 21, 2019 9:10 am

Re: Auto Level Fail

Post by ztatic » Mon Jan 21, 2019 9:25 am

I was having this problem until I learned that parameter settings have to be saved to EEPROM using the M500 command (for later recall) after any change. (In my case this was after a firmware update on an old Mini that lacks an LCD display, where I had to reset the steps per unit using the M92 command and Z offset using the M851 command.)

In the old Mini at least, interestingly and IMO problematically:

Without running the M500 command, you will still see your changes confirmed when viewing the parameter values via the M501 command. The M501 is supposed to be reading out the EEPROM contents, but they won't be actually written to EEPROM until after you have run an M500.

I can't find a list of M codes anywhere on the site or in the manuals, but this is sort of a hidden clue located near the bottom of the "no LCD display" section of the page on updating the firmware using Cura (https://www.lulzbot.com/learn/tutorials ... rough-cura).

If anyone knows where Lulzbot hid its list or wiki of Lulzbot-specific M-codes (and G-codes, of course), hopefully tagged by applicable printer model, it would be great to have the link.

If it doesn't exist (dear admin), I think it should, including an introductory paragraph describing the M500/501/502 commands and a review of the various firmware updating procedures.

I did find in the Helpful Links! section of the forum (viewtopic.php?f=7&t=231) a RepRap G-code wiki (https://reprap.org/wiki/G-code), but beware: some of the commands are different for different implementations, thus requiring some background knowledge.

zachah
Posts: 65
Joined: Mon Jul 31, 2017 9:20 am

Re: Auto Level Fail

Post by zachah » Mon Jan 21, 2019 5:12 pm

Since our printers use Marlin firmware you can use the G/M code reference on the Marlin FW site:
http://marlinfw.org/meta/gcode/

ztatic
Posts: 17
Joined: Mon Jan 21, 2019 9:10 am

Re: Auto Level Fail

Post by ztatic » Tue Jan 22, 2019 2:06 pm

Thanks.

Well, I guess this is the link that should be in the HelpfulLinks! page, rather than the one for the RepRap wiki.

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