I guess it depends which part you’re talking about. The bed is “lower” by virtue of the nozzle position being higher, as seen in the picture above.
In any case, I “adjusted” it – actually, it seems to have adjusted itself after, for the first time in a year of owning this printer, crunching into the washer due to an unclean nozzle. The irony is that was the final probe I planned to do to record the numbers pre-adjustment. After resetting the machine, wiping the nozzle, and running another probe, I found the numbers were much closer without any manual rod-turning:
Yep, you’re right, I was thinking about it backwards. The bed is fixed. The system just “thinks” that edge of the bed is lower because the Z-axis is out of adjustment higher on that side. That’s probably why every time I go to reset the one at the school where I help out, I start by adjusting it in the wrong direction.
After installing the new version of Cura, when I want to update the firmware, do I select the “Install Default Firmware” from the machine menu (as opposed to the “Install Custom Firmware” option).
Also, there is no separate file to download for this firmware, correct? If I downloaded Cura v21, that comes with this firmware update?
Lastly, if I recall correctly, updating the firmware will cause me to lose the customized E-steps setting I entered (as described in your One-click Firmware Flashing page). I think it will also cause me to lose the customized z-offset I saved as well, is that correct?
Rather basic questions, but it’s been a while since I’ve updated the machine. I just want to make sure I’ve got the proper procedure before going in to the school to help them do the update.
Definitely wait for Nick’s response, but FYI if you open the control window in Cura and in the lower-wight corner type “M501” then press enter you should get something back like the code window below. Notice the M92 line towards the top shows you your current E-steps setting that is in your Mini’s firmware and the M851 line at the bottom showing you your current Z-offset value. E833.00 and Z-1.23 respectively on mine. You can type M92[Enter] and M851[Enter] individually to get the direct values but I have the entire output from mine saved in a text file for future reference just in case.
Regarding the firmware, the latest ‘released’/supported firmware would be installed using the Install Default Firmware option in Cura.
Good luck.
Thanks, Doug. That’s how I did it last time I updated, but it’s been a while. The g-codes just don’t stick in my head if I don’t use them regularly. I’ve got the reset method bookmarked for the e-steps, but not the z-offset. (I’ve actually posted directions for others on here on both of these, but haven’t dug them back up yet.)
The default settings included in the firmware should work for 99% of people. But if you are worried about overwriting your settings, follow Dougz’s method described above.
Here’s the basic process to update firmware:
Install/launch Cura v21 (it comes pre-packaged with the new firmware inside)
Add/Select the appropriate printer and tool head in machine settings
Connect USB from computer to printer
Power on printer
Click ‘Install Default Firmware’
Click ‘OK’ to start the update process
Wait for completion
Close popup window
Print lots of stuff
Most of the folks I’ve heard from seem to have found that the Mini over-extrudes slightly with the default e-steps setting (833 if I recall). I found it printed acceptable out of the box with those settings, but it did even better when I tweaked it down to 820. I arrived at the 820 number by following your e-steps calibration procedure, but slowing down the extrusion speed in that procedure from 100 to about 40, which more closely approximates the extrusion speed when actually printing. (When I used the 100 speed, I was getting around 845 - 850 or so, if I remember correctly.)
I tweaked the z-offset because the HIPS we were printing with was sticking to the bed so well that the school kids were gouging the bed with the removal tool when trying to remove the prints (you can tell them to keep the blad of the tool almost parallel to the bed, but when it sticks hard, some of them just can’t resist.) I know this might create a risk of a print not sticking, but that hasn’t been an issue yet - and at any rate, I’d rather have a failed print than a damaged bed. I know we can adjust for this within Cura, but but doing it in the firmware gave me a value that “sticks” if someone uses a different computer to control the printer, or pokes around where they shouldn’t. (It also makes it easier to remember if you do need to tweak in Cura: if you want to get back to where you started, just set it to zero.)
I upgraded to Cura 21 and pushed the new driver to my Lulzbot Mini. Not so good. The bed leveling no longer worked. It was hit-or-miss on the front-left corner, but the front-right failed every time. Never got to the back corners, of course. I cleaned off the print head, but that didn’t help. Went back to 19.12 and loaded that driver. All is well again.
When it wasn’t working, the right corner failed almost instantly. I didn’t catch what was happening, but I’m guessing that the head never touched the washer.
I see others have the new driver working with the Mini, so I guess it’s something personal. Any thoughts about the cause?
When you do autoleveling in 19.12, what are you seeing reported for the heights of each corner as the head touches the washer? They all should be rather close. If they are not, what may be happening is that the left and right side of your x-axis carriage are not the same distance from the print bed. This can fool the safety measure built in to the auto-leveling sequence into thinking that there is a problem making contact with the washers on one or more corners (when in fact, it just gave up trying before it reached them).
If this is the problem, you may need to turn the power off to the stepper motors and adjust your z-axis screws so the left and right sides of the x-axis carriage match. Run another autolevel, and see if the numbers for each corner come out close. I’m not sure how close you have to be, but I’ve found I can easily get all four corners to read within less than 0.1 mm of each other. (This method really only adjusts for differences between the left and right sides. It does not handle front-to-back problems.)
To build on what John said, raise the z-axis to about 250mm. Then measure from the top of the X axis rod to the top of the taz frame (the plastic pieces the z-axis rods are mounted to) on both the left and right sides near the z-axis screws. Adjust whichever z-axis screw needed to make the x-axis rod level to the frame.
Osprime has a Mini, not a Taz. Measuring gets you close (very close, if you measure and adjust carefully). I just find it simpler to use the readout from the auto-leveling sequence to see how far off level it is - no tools required, and very accurate.
The newer firmware is a bit more strict, but the end-goal is to prevent damage to the print surface. Here at Aleph Objects we’ve had over 150 Mini’s running this generation of firmware 24/7 for at least the last 6 weeks without issue. Granted, these machines get all the TLC they could possibly need. If you can’t get it working following the suggestions above, please get back to us and ask for more help.
This is what I just saw for z values when I ran the leveling with 19.12 driver: -2.43, -3.10, -2.95, -2.38. I think this means that the right front and right rear both need to be raised. Do I do that with a clockwise rotation of the adjusting screw?
That is significantly out of whack. If you were adjusting the BED, you would be right that you need to raise the right side. However, what is really going on here is that the right side of your x-carriage is raised up. Your printer “thinks” the right side of the bed is lower, since it has to travel down further to reach those corners (in reality, it’s just starting from higher up).
You need to lower the right side of the x-carriage by adjusting the z-axis threaded rod on that side. I can’t recall which way you need to turn things, but you can find out by watching which way it turns when you give the command from within Cura (or whatever printer control software you are using) to manually move the print head down. Once you’ve established the direction, turn off your stepper motors (I believe there is a button in Cura for this in the control window. If you can’t find it, you can just power down the printer entirely to make the adjustment. When you are done, run the auto-leveling sequence again to determine whether the adjustment helped.
Thanks, all. I am happy to report that I now have the new driver working with my Mini. I fixed up that right/left mismatch as instructed. I had to turn the screw counterclockwise (looking down), then some back and forth to optimize (-2.21, -2.22, -2.06, -2.17). Then I re-installed Cura 21, pushed the driver and it’s happily printing right now.
I appreciate the additional instruction you folks provided. At first I thought we were talking about the screws in the centers of the washers. I couldn’t see how turning them could accomplish anything. After reading the subsequent posts, the screw being referred to is, of course, the very prominent one that is responsible for making the print unit go up and down. Duh!
While I was playing around with this, I couldn’t help but think that it might not be too hard to come up with a sequence of commands that would operate one of the screws to straighten out a situation like this. That is me speaking from a position of near complete ignorance!
Whether that is possible might depend on if the motors are controlled separately or wired in parallel (since normally they would be getting identical commands anyway). I’m not familiar enough with the mini hardware to say one way or the other. It is an interesting idea.
I did post this issue in a separate thread relating to Cura ‘not responding’ issue at the middle of long prints (was suppose to print for 50+ hours couple of days ago and currently in the bed is a 23hr 42 min run), but I reckon this is the most relevant thread though as it pertains to v20 (I have v20.01). Although I am using TAZ6.
Just before I log into this forum, I am experiencing for the third time now the above anomaly of Cura ‘not responding’, this time in about 60% of the current 24+ hr run. In previous experience of the same anomaly the printing continued until I needed to force stop it due to filament runs out. The printing still goes on but I just have no way to ‘Pause’ it to refill.
I have sufficient length of filament remaining in the reel in this current run.
During the first two failed run due to Cura ‘not responding’ it took more than 30 hours before the anomaly. However, I noticed during the past two failures that the error ‘not responding’ actually occurs in around z=100 into printing. Are there any similar experience to this before and what is the fix to enable Cura to respond all through the completed print height.
I am printing up to z=150mm this time, it was originally set to print to z=250mm, but was reduced since the initial 100 mm of height was printed prior to the previous error at z=100.
