Hi!
I have a weird problem and I really don’t know what I can do to fix it. I want to print a large 3d Model with my Snapmaker 2.0 A350T. I am currently using the eSun PLA+ White Filament as this is the only one I have left. When the printer starts printing it perfectly prints in the front and back part of the heat bed, but it doesn’t print in the middle part (See picture). I never saw this before and tried it many times with different setting and calibration. I tried with Nozzle temperature 200, 205, 215 and 225 degrees celsius. The heat bed is 70 degrees celsius.
One can see very thin lines in the middle part, but it doesn’t print in higher layers at all. No filament is coming out of the nozzle, but I can manually run some filament through.
I tried to slice the model with the Snapmaker Luban a few times and I also tried it with CURA but I get the same result. When I print with the Snapmaker Black PLA filament there seems to be no problem.
I printed already with the eSUN PLA+ filament before (other smaller parts) and it worked just fine
This is a bed levelling issue. When the bed heats up, the center of the bed is higher than the sides, so while the nozzle may have the perfect height on the edges, it is too close in other areas. First try increasing your initial layer height to 0.32mm. You can also do a 5x5 heated manual calibration for best bed leveling results. Beyond that the machine will require tramming, shimming, and modifications.
Agree with Mxbrnr, it’s how you installed the bed. Try this: loosen the screws so the bed is floating on the frame. heat the bed to 75C and let it sit there for 30 minutes. Come back and tighten the bed down, working the screws from inner to outer in a pattern similar to a tire (cross bolts). When you tighten the screws, don’t crank them tight; ‘hand tight’ (aka stop when you feel tension from the bed). Then do a 5x5 or 6x6 bed level. You’ll need to do a card test for z-offset and then print something to actually adjust your z-offset so it looks good.
That’s what I do, haven’t had a single problem with bed leveling.
@Mxbrnr@Mads0100 thank you very much for your help. It works perfectly fine now. I followed the steps from @Mads0100 and I set the layer height to 0.32mm and did the 5x5 heated manual calibration from @Mxbrnr.
I haven’t done this method of loosening the screws and heating before snugging them down. That’s a good thought.
I am not having many problems with leveling with the new dual extruder, its routine for calibration is pretty good in my experience (but only after you get through the initial calibration so you can run the sensor calibration routine).
I am going to try to the screw thing next time I calibrate since why not
I am not in a hurry to get my glass bed back on which I did not expect.
I typically let the beast pre-heat for awhile to the temp i use or a little above and let it sit before doing the calibration (15 or 20 minutes is plenty) and then also I may also pre-heat the bed before doing a job too, particularly if its a big object that will require a lot of print time (more surface area can lead to more areas of bad z elevation)
Just some extra food for thought on it
when it comes to the leveling test prints, i fully admit i am lazy and skip that. i just kinda watch the first layers of the print and fine tune if needed, the last time i calibrated it was close enough for baseball, but im not always that lucky. When one area of the print looks good and another doesnt in terms of extrusion on the bed, that is when i get a bit flustered and just try to find a middle ground and let the layers stack up til it evens out. this results in less than perfect models but there’s only so much that can be done with the thing without getting into any platform modifications or shimming. this is where the glass bed comes in nicely, but i am not in a hurry to hack open my dual extruder module.
As it turns out, the heated bed screw theory doesn’t help as much as many think, but can help with overall reliability…if done in a very specific manner…so it is still generally recommended. I just wouldn’t put too much faith into, nor expect much outcome, from a process that can be empirically proven to have very little effect in many cases. Details in the linked thread…
For me it just worked with loosing the screws and heat the bed to 75 degrees for 30 mins. I tried it before with just 5x5 heated manual calibration and the 0.32 mm initial layer hight. It worked already much better with that, but not in the center of the bed. Then I tried it with the screws and it worked perfectly fine. So I am happy that I had both advices from you guys because combined they worked great.
