Autobed Levelling with TMC2100

I’m having issues with bed levelling, I’ve got a spare TMC2100 lying around, I’m wondering if it would be worthwhile using that as the Z-Axis driver and running both Z motors in series, then using the endstop function of the TMC2100 as an autolevelling sensor.

Would this work or am I mistaken?

If i may ask what seems to be the problem you are having with bed leveling? I do not experience with the TMC2100 but all 4 of my printers run Auto Bed Leveling.

I think you’ll have a lot of trouble. The TMC2130’s endstop detection isn’t perfect and you get an enormous amount of force from the leadscrews on the Z axis. Plus, the nozzle will hit first, and it will be pushing on the bed, which is not nearly as rigid as the X or Y axis stops. You’ll probably smash the bed enough that it won’t give accurate results.

All that aside, I’m sure you’re really wondering if the motors wired in series will even trip the endstop detection. I honestly could see it going either way.

Maybe between Mitch and I we can solve your other autoleveling problems. I have used an inductive sensor and a bltouch on my mp3dps

I have capacative and micro switch as my ABL triggers. I am sure we can help.

I’ve been using manual mesh bed leveling with pretty good results, I’ve managed to print 60% of the lowrider v2 but I ran into issues last night and today, a biggy is that the Bed-Z doesn’t seem to be holding, I auto level the bed, print a part, then the next part I have to reconfigure the Z-Bed offset for it to adhere correctly.

When it works it’s great, But I’m finding slowly the mesh will become inaccurate.

Maybe I’ve been impatient the last 24 hours, but the manual bed leveling seems to leave a bit too much variance for my liking. So I’m thinking if I can run an auto level mesh at the start of each print it should make things a lot easier.

 

My layer height is .28mm

Hotend is a .4mm Microswiss All Metal deal

Bed is an aluminium heat plate

Running Marlin 1.1.9

 

Clipped to the bed is a sheet of 1.5mm polycarbonate that’s been washed with acetone (My preferred surface, things seem to stick really well and come off easily - I had no problems with the anet a8 and 80% of the parts that I’ve already printed on this build)

 

Should I take the plunge and order in a BLTouch? or should I be looking somewhere else?

 

I’ve upped the mesh to 4x4 incase the bed is super out, but it doesn’t seem to be helping much.

Maybe my method of leveling is off? I’m running a piece of paper under the (heated) nozzle and (heated) bed, then with it catches I back off a bit and try to get it as accurate as possible, as in, the one step that causes it to catch.

 

The BLTouch mount I have really only works for my hotend, but anything you can mount is orobably a good choice. FTR, it’s actually a 3D Touch from alibaba.

One thing I noticed is that if there’s tension in the filament, it can pull the nozzle up 0.1mm or so, which is enough to make me mad. I installed some PTFE tubing and that helped.

I’ve never tried manually leveling the bed, but I bet it would work. I wonder if that bed leveling printout is stored someplace on my octopi. It would be interesting to see it over the course of a few months. I also took out the springs on my V2, since I don’t have any desired to level it using the screws.

You ahould also watch out for the motors slipping when you’re not powering them. If one moved, that would blow up your precious measurements. Someone (Bill?) Made a little flag you could print and attach to the top of the leadacrew to give you a visual indicator if they got bumped. You would just adjust them to be pointing the same way, and if you were about to start a print, you’d check them.

What kind of bed level sensor are you using? I have solid mounted my bed as well. I run an auto bed level in e ery print for my prusa style printers. I build it right into my slicer code. Also unless you are skipping steps on the motor or your z steps per mm change z offset should stay fairly constant. Are you using the level sensor as your z home as well?

Mitch, he’s doing manual leveling, where you move to an X,Y, then adjust the Z and save the point in firmware. Rinse. Repeat. No sensor.

Hmmmmm okay. When he said he auto bed levels everything i was thinking he had a sensor. My misunderstanding, sorry.

Cheers for the help,

I ended up coming to a solution -

Set up UBL Leveling by connecting Z_MAX to the hotend, covering the polycarbonate in tin foil and glue…

Worked surprisingly well, I think I’ll be using the same method in the future.

The trick for new players is that the UBL test print likes to print about 2-5mm off the actual set height, but that was an easily overcome obstacle.

I didn’t at all spend way too much time on it, pull out my hair or go through 1/4 of a roll of filament.

So you covered your bed with foil and then added glue (for adhesion?). Then connected ground to the foil and a clip the the nozzle and ZMAX?

I’ve got to try that… I’d think a quick spritz of isopropyl on the bad then laying a sheet of foil down would work as well as glue for the duration of the test. I’d have to remember to disable the normal home at start of print though to make it so I didn’t have to reconnect the original Z end stop.

Though with an aluminum bed you wouldn’t need the foil, but you would need the nozzle at temp so you don’t have to deal with oozed and cooled filament isolating the nozzle tip.