I would like to ask the community for any feedback regarding my bed leveling values.
As many of you I have issues to realize a “first-time right” result with my Snapmaker A350. Every print need a lot of attention and support.
Nonetheless I love the concept of a modular system!
Maybe somebody can give me feedback regarding my automatic bed leveling values G29s requested by using M503?
I get similar range values whether hot or cold printing bed.
I bought for this test a brand new printing sheet (of course never used fpr printing) to avoid any deviation due to the sheet itself.
This thread should be very helpful to answer your questions. In general, it boils down to how “bumby” your bed is. So, not the values itself, but how they are distributed across your bed matters. A gradient, tilt or curve can be compensated by the auto leveling, but bumps, dents, wobbles are an issue. In my case (Kickstarter A350) I realized that not the bed frame is the culprit (which it also can be), but the heated bed PCB actually is uneven like hell.
Solutions are either to work with shimming to try and force everything into shape, or work with denser auto-levelling patterns. With my old platform and bed I needed to go for 11x11 mesh to get somewhat uniform first layers on large prints, with the newer platform but still old bed the densest pattern of the dual extruder (5x5? don’t remember right now…) seems to be just good enough, but I did not run very large prints with that setup yet.
It’s a total variance of 1.06mm. It’s not good, but sadly VERY common.
Seeing how the numbers are arranged, the first thing I would do is make sure the gantry is squared by shutting power off, and then manually pushing the X/Z rails all the way to the top, and force each side up until it physically cannot move any further. Then try a re-level and see if that has helped at all. You could also try the 1-2-3 machinist block method if you have such tools available. The good news is that it appears the variance comes from everything just leaning to the left, so it should be fairly easy to fix.
I actually just finished up a round of bed tramming on my machine yesterday. It took several days of measuring, adjusting, and re-measuring to get it. It’s a pretty time consuming and tedious process. I was able to get mine from a stock variance of 1.1mm down to 0.19mm, and I still get areas of the bed where the ABL struggles to compensate for it.
Do not underestimate the distortion and strength of the heated bed. It makes absolute no difference having a nice flat frame that some have taken great trouble to level out: I screwed the heated bed to 12mm MDF wood and the distortion when heated was enough to make the wood curved, up in the centre and down at the corners. You could see the gap when it was laid on a flat surface.
Did you try heated leveling and let it expand for 30-60mins?
1mm difference relative high.
Do you have a bracing kit?
Are your sliders of the linear module loose?
If find the numbers not too disturbing as they are mainly following a gradient/trend and have no significant up’s and down’s inbetween. However, a 5x5 matrix is perhaps not the most informative thing. I’d recommend to at least once do a 11x11 and create a map to visualize the surface (e.g., using Octoprint or Excel).
I have tried heated and unheated. I will repeat my tests with longer heating time!
No bracing kit available.
I doublechecked all sliders and the heating bed. I have unscrewed them and screwed them again. For the heating bed I followed the recommendation of [Mxbrnr] " Heated Bed Screw Torque Amount".
Hey @Mxbrnr
as proposed by you I did the manual pushing of the X rail fully to the back and the z rail to the top and did the releveling.
I have leveled the bed as @xchrisd suggested one cold and one at least 35min heated.
And finally I did two level test with 11x11 approach as @Hauke mentioned.
Just to be sure. Am I right to assume the values given by M503 G29, indicating “I” as the X axis and “J” as Y axis?
here you will find pictures of the platform attached. Hopefully, the installation is right.
I mean, eventhough I am sure, I doublechecked with the instructions, since you never know!
“Trust me I’am an engineer!”
Strong tilt, and bumpiness. Welcome to the club The tilt can be compensated by bed levelling, the bumpiness to some extent only. Since your device is new, I’d consider checking back with Snapmaker if they are willing to replace parts.
@Mxbrnr I tought I will measure the my Z axis after pushing them back all the way to the top.
After turning the machine on and moving back to home I realized that the deviation between left and right increased after the automatic home movement compared to the manuel pushing back deviation even significantly.
Something must be wrong. And yes the limiter switch on the right Z axis has been screwed too tight and the limiter is broken. Therfore any automatic home causes a deviation in the Z axis.
That won’t actually do it because the machine stops both z-rails as soon as either of them hits one of the two switches. It doesn’t care which one is activated, and it doesn’t need both. This could be caused by a backlash issue and/or worn linear screw nut though, possibly other things I can’t think of at the moment.
Did you buy this new, or used?
Mass production as inexpensive as possible. To get closer tolerances requires an exponential increase in production costs. You have to keep in mind that these are consumer-grade hobby machines, so they do not have anywhere near the precision of industrial and machinist quality equipment.
The tilt can be compensated by bed levelling, the bumpiness to some extent only. Since your device is new, I’d consider checking back with Snapmaker if they are willing to replace parts.
