I’m curious if the Snapmaker team has had any luck eleviating these issues that plagued all of the early adopters. @Tone singlehandedly made my 350 a 200, while it was unable to print anything bigger than what the Orig. Snapmaker could handle previously.
Do we have any fixes to 3d print bed issues? The only possible one from the road map might be the linear module upgrade?
Some recognition that there is indeed a problem would be nice, that it’s not just one or two machines.
They have acknowledged this, and are working toward adding a preheat routine to the calibration which helps.
Preheat to 5 degrees hotter than your temp before a calibration makes a big difference
Frankly I am beyond that now by switching to a glass bed, which is even better
I read somewhere at the forum that a 11x11 leveling routine from snapmaker is coming out…- Don´t know if its true.
There is an upgraded “cage” alias “platform” available, which has milled screw places, don´t know how this is called.- I have ordered such a platform but its not that good as expected,- haven´t tried so far.
I print good with my milled cnc-wasteboard with the heated bed on.- I have this now since one year, i guess, and no troubles so far.
But its a good question and it would be awesome to get some feedback! @staff
Unfortunately, I have tried this and it has only minimally helped. As far as I can tell, the problem I mainly face is that the bed “wobbles” very very slightly when the Y axis moves back and forth. This is enough to prevent first layer adhesion in my case and I’ve tried several various recommendations. I’ve received one replacement linear module which also minimally helped.
I haven’t gone so far as installing a support roller module like I have seen on some threads. That level of kluge feel way over the top to get the printer going, and if I need to spent 100$ to get decent bed adhesions, well… At that point I’d just save for a Creality machine or something.
Sounds like your linear modules (at least one) probably has a loose head.
I had a very loose Z axis that was problematic
this was a warranty replacement issue.
if you take everthing off try to feel how much play is on that bracket, video tape it and post it here then email support with a link to it explaining
i have some videos about my struggles wiht that, i can go back and find you the threads if you are interested.
Yes I also went through this regamarole and they replaced one linear module, but it only minimally helped.
@MooseJuice same here. The glass bed and @stewl’s write up of the IR sensor (which saved me so much time from doing one myself, thank you stewl!) has made it so much better. I’m considering doing a pei coating test run on the glass to improve adhesion. Glass by itself can be a pain for it sometimes, mainly with ABS.
Levelling just got better! The fix for the levelling error is in GitHub and my single test was very good.
I use clean glass for PLA and PETG and if I am having trouble with adhesion I use Magigoo. I dont have an enclosure and little need of ABS - is just too hard, all ways! Magigoo do a special high temp version for it that I have not tried.
Potential Issue with Bed levelling process - #41 by stewl
Aren’t they going to adhigh magnitude bed leveling with heat on and proper positioning? I’m not very familiar with github…
This code fix will come out in a firmware release soon. I dont understand what you mean by high magnitude leveling. The GitHub fork just fixes bed levelling so that the levelling used when printing matches the bed levelling. It doesn’t do anything to add heat to the touch screen levelling. Last time I tested though if you set the bed temperature using the terminal with M140 S65 or what ever temperature you want, let the bed heat up and then do levelling using the touch screen, the heat stays on…
By high magnitude here I mean 11x11 auto leveling or higher grid count.
OK.
This is a controller change. The code for the touch screen has not been made public so no idea what changes will be made but there is nothing in this fork for it.
If you still have to use G1029A for levelling points above 5x5 the bed will be turned off as the the necessary code change is definitely not in this fork.
Currently, we are testing to heat up the heated bed first and then do the auto-calibration. If the test result is fine, we will release a firmware supporting to heat up the heated bed first. It is optional. Customers can still do the auto-calibration first and then heat up the heated bed.
@WilliamBosacker i don’t foresee them having any issues as people have manually overridden it in the console and told it to stay on during leveling, speaking of EMF though, I wonder how long the heated bed will maintain it’s magnetism over time and how many heating cycles it will last.
@WilliamBosacker its most certainly not an HET. Which is a reason why I brought up the whole magnetism on the bed in the first place, a Hall’s output voltage is directly proportional to the strength of the field. I’m quite curious as to what they do use.
@WilliamBosacker quite familiar, I do it as a hobby also built my own coil 
dunno how I didn’t think of it before 
The height sensor is an inductive type sensor. Their measurements are affected by changes in temperature as well as magnetic fields, both from the DC current flowing through the bed heater traces and the permanent magnets.
The working theory found on many forums is the most accurate readings would be obtained with calibration done without any bed heater current, at a constant temperature throughout the entire calibration, and also with no measurements taken directly above the bed’s permanent magnets.
The strength of these effects is debated widely, from imperceptible up to deal breakers making some (non snapmaker) machines unusable.
Early on in the snapmaker firmware history a quick z calibration check was preformed automatically before printing, after the bed was heated. This had to be scrapped as it resulted in the toolhead crashing. It was presumed at the time this was due to the presence of current in the bed heater and/or the change in bed temperature compared to the previous cold calibration. After further testing it seems now the engineers are saying the effect of DC current induced magnetism is smaller than the thermal expansion of the aluminum platform, so a hot calibration even with the bed heater current on would be more accurate for printing than a cold bed.
Details on the exact sensor used can be found here Anyone have the proximity sensor part # - #50 by dstarke
Edit: there is also debate about the influence of magnets on the accuracy of the sensors. This post was intended to be a summary of previous discussion / literature review of other forums across 3D printing where this had been discussed. I have not verified the accuracy of the information.
I do agree that an air core eddy-current based induction sensor should be insensitive to magnetic fields.
Added a disclaimer to my post above, that was a literature review I have found about discussion on the topic online. However I do agree with you than an air core inductive sensor should be indifferent to static magnetic fields.
At present, I gave up on auto-leveling w my 350. I would have far more faith in the mechanical pin activated detector than the OEM unit in my KS 350. At least that would eliminate the issues discussed above about accuracy and reliability of the current unit.
While I understand, I for one expect one on the major feature upgrades for the SM2 to work properly. This is also the reason I don’t kluge additional rails or add a glass bed. Perhaps I am being obsinant, but as far as I see it, I’m giving the needed feedback. Also. I do appreciate all who have responded with various fixes. Perhaps SM team can introduce some of these additional hardware fixes.
Looking forward to the next firmware patching, and hope it will make a difference. None of the patches over the last 6 months seemed to have fixed much in the fdm processes for me.