Back Left Corner of heating bed has issues with lifting


#1

Hello,

I’m wondering if anyone else is seeing this problem?

I am having issues with the back left corner of the heating bed. It seems when printing with anything without a raft that at some point it starts to lift from the back left corner. I tested this with a 65mm disc on Default Normal settings + Skirt (snapmaker reel adapter washer from thingiverse). That corner will start to lift after a while and eventually the disc comes loose completely from the bed. However when I offset the print to print in the front right quadrant (furthest from the problem area) it works fine. No issues at all.

I first noticed this printing the large snapmaker accessory box from Thingiverse. The entire back left corner print area lifted about 2mm. At the time I thought it might be the room/cooling, however I put the entire unit under a plastic box to shield it from any drafts and to help even out the temp a bit maybe. It didn’t help unfortunately. Only offsetting the print to the front right corner has really proven reliable.

Does anyone else experience this or have any suggestions? I checked and the bed appears level. I’m going to try and check the heating temp across the bed surface if I can.


#2

Sounds like the back left corner is a little lower. You can also try upping the bed temperature. 60C seems to work better for me instead of the default 50C.


#3

Raft appears to work well too. I’ll try upping to 60C. Is that only for the initial layer or for the entire print that you use 60C?


#4

That’s an interesting thought. I’ll have to try dropping it back down to 50C after the first layer. Usually I use 60C through the entire print.


#5

I’m having the same issue. This is really annoying as it’s ruined a couple of prints already. I wish there was an option to turn the fan on the extruder off, at least for the first layers. I’m already calibrated as tightly as possible, using a rizla paper as calibration paper.


#6

I rarely have issues with bed adhesion because I always use glue stick on the bed. I’ve found that it’s easier to get uniform coverage if the bed is warm when applying it.


#7

If you really want to be precise, consider using a feeler gauge. :slight_smile:

As far as turning the extruder fan off for the first layer, some slicers like Simplify3D would let you set that. Or bump up the bed temperature for the first layer.


#8

Already bumped up the temp of the bed for initial layer to 60. also calibrated with a feeler guage (which doesn’t really make a difference). The warping is caused by rapid cooling of the plastic, so it’s kind of essential to be able to turn that fan off. I refuse to pay for software for only one feature, I’ve seen the option in multiple softwares already. But people are saying snapmaker does not support turning off the fans. In that case, it’s a clear shortcoming of the machine.


#9

It does not support it. The fans are wired right from 24V to GND. As soon as the printer gets power all fans are at 100%. You could always wire a switch in line with that fan though and stick it out the side vent.


#10

Did anybody figure out how to fix this? I’ve tried even upping the temp to 65 C, but the back left corner always lifts up. It’s becoming quite annoying as the filament won’t stick. I’ve tried re-calibrating and it didn’t work. Always the same back left corner.

Should I try re-calibrating closer or farther away?

thanks,
Greg


#11

You can try re-calibrating closer for the back left corner (position 1). Also, once you calibrate positions 1-4, go back to position 1 to make sure it is still calibrated. Sometimes I noticed that when I’ve made my first round of calibration, when I go back to position1, the calibration was off. Worth a try.


#12

Thanks @kelvin8r! I’ll give that a shot. With most prints it doesn’t mess it up at all, but it may really mess it up in the future. I’ll try to post pictures too :slight_smile:


#13

If other prints are not messing up, perhaps it could also be the project file itself that is the source of the problem? It could be that the object is not flat but slightly lifted in the back left corner. One way to troubleshoot is to rotate the object 90 degrees in the slicer and see if the problem area is rotated as well. Good luck!


#14

Does this happen when it’s too close or too far?

sorry for the blurry picture.

But you can see it gets wavy and stuff.

Thanks,
Greg


#15

That is a symptom of over extrusion, not calibration.


#16

So I should set the extrusion to 95% or so?


#17

I’m not really sure if it is either. It may just be Cura messing up. Others have reported the same issue. The extrusion seems to be very jolty in when moving left and then down. I’m going to try SnapmakerJS and I’ll get back to you :slight_smile:

-Greg


#18

Sooo I fixed my problem.

It was a mixture of many many things. The first thing I did was adjust the z-offset. I found that an increased offset lead to better (but not perfect results). After this, I attempted to decrease and increase the extrusion rates. An increased extrusion lead to better results and a nicer first layer.

Now, the problem still had quite some issues and I was getting fed up. So I decided to calibrate my extruder again, and to my surprise I was under extruding by a whole 10%. I quickly sorted that out and then tried another print but the corners weren’t sticking.

Last ditch effort was cleaning the bed 3 times with rubbing alcohol. And wabam! It finally printed perfectly! I have an even first layer and I can print on the entire surface again!

Thanks,
Greg