bbbenji / pmsblm Goto Github PK

Why not use the auto-bed-leveling with the minda-probe on the prusa-mini?

since the bed-leveling seems a design-bug in the mini (maybe fixed with firmware),
see this one for the hw-bug, and more on the prusa-forum

why do it all mechanical like your way?

Hi,

I've used your tool and mod in the past to greatly improve my bed leveling on the Mini. Ever since the update to 5.1.0 however I can no longer use your tools as the output from the Mini no longer produces the original mesh but instead outputs nothing when just probing with G29. If requested to output a mesh, the mesh is a lot different than before.

G Code:

G29 ; Probe mesh
G29 T ; Display probed mesh

This produces a mesh that looks like this (and yes, my arm is not square at the moment as indicated by the mesh):

Bed Topography Report:

    (  -41,226)                              (195,226)
        0       1       2       3       4       5
 5 | +0.251  +0.165  +0.054  +0.082  -0.055  -0.063
   |
 4 | +0.262  +0.164  +0.065  +0.012  -0.060  -0.133
   |
 3 | +0.249  +0.162  +0.076  -0.058  -0.065  -0.073
   |
 2 | +0.221  +0.152  +0.084  +0.009  -0.021  -0.051
   |
 1 | +0.317 [+0.221] +0.125  +0.030  +0.005  -0.020
   |
 0 | +0.359  +0.290  +0.166  +0.051  +0.031  +0.001
        0       1       2       3       4       5
    (  -41,  -48)                              (195,  -48)

Would you be able to modify your tool at https://bbbenji.github.io/PMSBLM/ to allow for this new Unified Bed Leveling mesh output?

Details (from marlin) regarding the UBL: https://marlinfw.org/docs/features/unified_bed_leveling.html

With kind regards,
Thomas

Hello!

This is an excellent addition or modification for the printer; I actually implemented following the instructions and results are amazing. Thank you for sharing this with the community.

I'm wondering how hard it can be to extend this project to the Prusa MK3S+ too ?

Thank you!

Rodrigo

For those who broke the appendix on their Buddy board and flashed Klipper firmware on it, Octoprint and Pronterface will no longer work.
But, Klipper has SCREWS_TILT_CALCULATE.
It even shows directly how many minutes you must turn the screws (counter) clockwise.

https://www.klipper3d.org/Manual_Level.html#adjusting-bed-leveling-screws-using-the-bed-probe
https://www.klipper3d.org/Config_Reference.html#screws_tilt_adjust
https://www.klipper3d.org/G-Codes.html#bed-screws-tilt-adjust-helper

So having this option added to the documentation would help others too.

The above is thanks to people on the Klipper Discord server for pointing me to the above links.

I'm in actual sourcing hell, and the best I've been able to find locally whose temperature resistance I can verify is 4mm ID, 7mm OD. Would this work, or is 3mm ID essential?

The latest MINI alpha firmware uses a 6x6 mesh size instead of 4x4 or 7x7, would it be possible to add this as an option to the 'G29 absolute to relative value converter & plotter' tool? Or even an arbitrary matrix size?

Additionally in 5.1.0-alpha1 G29 S0 no longer returns the mesh information as per the instructions - G29 C0 T1 returns the CSV values.

I noticed a ' at the end of the one command (G28 ; home all without mesh bed level`) Is that correct?

I'd like to do this mod, but I cannot find AXIC1052 anywhere. Amazon delivery here is hilariously expensive (more than the item in question), and the only nylock nuts I can find are about 4mm tall.

I took my bilinear levelling grid and used both the new and old methods and got different results. The old method seems to generate the current values whereas the new one generates invalid ones.

bilinear levelling grid

      0      1      2      3
 0 +0.074 +0.127 +0.051 -0.010
 1 +0.148 +0.146 +0.125 +0.128
 2 +0.057 +0.131 +0.171 +0.216
 3 -0.044 +0.165 +0.245 +0.329

Old

      Raw values:
      -0.19	0.06	0.19
      -0.04	0	0.03
      -0.07	-0.05	-0.15
      
      Degrees:
      137°CCW	43°CW	137°CW
      29°CCW	0	22°CW
      50°CCW	36°CCW	108°CCW

      Fractional Turns:
      2/5CCW	1/10CW	2/5CW
      1/10CCW	0	1/10CW
      1/10CCW	1/10CCW	3/10CCW

New

Raw values:
-0.06 +0.04 +0.10
-0.00 ±0.00 -0.05
-0.11 +1.39 +2.89
Degrees:
40° CCW 28° CW 75° CW
1° CCW 0° 38° CCW
81° CCW 999° CW 2079° CW
Fractional Turns:
1/10 CCW 1/10 CW 1/5 CW 
0 CCW 0 1/10 CCW
1/5 CCW 14/5 CW 29/5 CW

I used the 16mm screws and cut the tubing with the jig (10mm), but it was super hard to press the heat bed and tubing down to get the screw threaded onto the nut. I ended up cutting 2mm off the tubing. I think 18mm or 20mm screws would work and make things easier. Thanks for writing this up, it's awesome and worked really well.

U cant use silicon from:
https://fmic.pl/laczniki-silikonowe/193-5923-przewod-podcisnienia-3mm-vacuum.html
The tube is 9.8mm OD

I seem to be unable to find the right silicone tubing - either the inner diameter is wrong, or it's regular silicone tubing with a heat resistance of 200°C and not the high-temperature variant.
Is it really important that the silicone tubing has a higher heat resistance than 200°C, when the Mini's heat bed only heats to 100°C?

Edit: the recommended silicone tubing from Amazon also gives a heat resistance of 190°C, so the others seem to be okay?

see image here: https://forum.prusa3d.com/forum/postid/654405/

Octoprint is showing my bed is a wave, with a significant low followed by a significant high. when averaged out, things are level, as the converter, despite plotting correctly, shows little or no adjustment needed.

I'm not totally sure this is an issue with the converter, mind you.

Thanks for the tremendous work! I already installed the mod 1-2 years ago and just came back to recalibrate the bed. I noticed several things that should be adjusted in the documentation:

1. Replace vs. re-place vs. put back? Well, I'm not a native speaker and I'm not 100% sure what exactly is meant by "replace" (Make sure you replace your steel sheet). Presumably it means that the steel sheet should be put back on the heating bed. It would be nice if this could be formulated more clearly.

2. Can you please expand the text to say that the link provided should be used for the old firmware and the new link (beta) for the new firmware? It took me quite some time to figure that out.

Hello, thanks for the great guide. Just finished it. My feedback below that could improve the experience of others.

1 - the 16mm screws are DIN 965 or DIN 7991 and all HEX and CROSS and TORX versions of the screw in size M3x16mm work. I personally used a CROSS DIN 965 M3 x 16 mm without issues. The screw head is flush or slightly below the level of the heatbed. Those can be bought at most hardware stores.

2 - The Hexagonal M3 nut height is really superimportant and should be highlighted that basically ONLY "axial m3 nut" by company Axial works. They build RC cars. There is no DIN number for those. They are custom made for their RC cars. I had to buy them online from an e-shop. The offer of the Axial M3 nut is quite large, most RC eshops sell them.

3 - Probably hardest for me was getting the hose since most of them are 3mm x 7mm. But in the end i found it in a TUNING car e-shop.

4 - There could be mentioned that at Installation step 10, a good guide is to place the spacers beside the silicon hoses and finish screwing just slightly above them. You can avoid a ruler then, the spacers are exactly 6mm (or 6.06 in my case).

5 - Just before Leveling Procedure step 5 there should be added "Replace your metalic PEI print sheet". It is not obvious and doesnt work without it. It cost me some time, and introduced uncertainty into the process. There should be mentioned then, that after modifying the screws, the user should replace the PEI sheet and wait for the bed temperature to stabilize on 60. Since if the screwdriving takes long it can drop as low as 56.

6 - Although i used the 3D printed M3 wrench, i would mention there, that the wrench is slightly bigger and allows a few degrees free movement of the nut inside. So i would either mention to get a metal one, or to first properly "seat" the M3 wrench against the nut to properly brace against the screwdriver movement.

7 - at step Leveling procedure 7 there should be mentioned, that sometimes in windows, when copying the text output from Pronterface, windows out of some reason dont copy the new numbers with CTRL-C and keep pasting the old ones. So i recommend selecting by mouse and right click COPY.

Everything else is pretty awesome and i thank you for the guide!

In step 6 when mentioning the output, please include the first row of "0 1 2 3" to ensure that people copy it over. I was confused at first and truncated it and drove me crazy when the back left screw did nothing 😅

Will the DIN 965 torx screws and nuts recommended for this procedure also work on an MK3S?

The model is on printables here: https://www.printables.com/model/43629-prusa-mini-silicone-bed-leveling-mod-bed-tightenin

Without it, I don't think I would have guessed how much to turn each adjustment very accurately - so it is definitely a help in my view.

I would suggest adding a link to it in the Requirements section - as an optional tool.

I did the mod and before there were no big troubles but now my right rear corner is waaay to close. But the Probe says its fine but it isn´t
Any Ideas?)
Things I tried:
Making the X Axis Straight to the bed
Flipping the sheet over
Checking for debree
Heres the Rear right Corner:

Left rear Corner for comparison:

My Assembly Looks like this:

Found that #3 mentions "the 16mm screws are DIN 965 or DIN 7991", which I'm assuming is why the guide says either works. My experience says DIN 7991 does not work - they ride just a bit above the head bed. Looking online, the head size for DIN 965 is 5.3 to 5.6, whereas DIN 7991 is 5.7 to 6. Perhaps the holes in some of the heat beds are a bit deeper and DIN 7991 can work, but certainly not with mine.

I'm waiting on some DIN 965 now, and I'm sure that'll work. Maybe I'm unlucky, but you may want to add a warning or remove the 7991 reference. 🤷

Thanks for the whole thing...awesome mod!