[H2C] Chamber Exhaust Fan & Corners lifting

[goodman]

Recently some of my large flat model printing job consistently occur corners lifting issue.

I tried these but no luck:

• Increase bed temp
• Clean bed
• Change into other PLA filaments

Then when I turn off the Chamber Exhaust Fan manually after printing job started it eliminate the corner lift issue.

Not sure the Chamber Exhaust Fan is the root cause for my corner lift case or not, but I would like to ask:

• What is the control logic of Chamber Exhaust Fan? (it seems programmed to be automatic）
• Can we control it manually? or put the setting in gcode?

Thanks!

FW version 01.01.05.00

[cege]

For me, it turned out, that the AUX fan (Auxiliary Part Cooling Fan) was the root cause. It’s blowing regulary at 100% and blows literally the corners up. I could control the fan within the filament profiles and turned them down to 40% and everything is fine.

[user_1083141284]

You could try to print one of the AUX fan redirection pieces which prevents the AUX from directly blowing at the print object.

H2S/ H2C/ H2D Aux Fan 45 Degree Deflector - Free 3D Print Model - MakerWorld

And you can try to modify the GCode to open the cooling lit at the top (see the solution linked in the first post):

H2D struggling in colder workshop (warping, bed adhession)?

My H2D has been running flawlessly since i got it early this year, but recently I’m getting more issues of warping and the print coming off the build plate. I did wash the buildplate but that didnt really work. Glue is a solution, but I never needed it before. I’m guessing the the exhaust fan is the main problem. The printer is in a workshop where the temp is now around 15C, as it is winter here. This means it is sucking in cold air, while the chamber isn’t too warm for PLA anyhow. I have been …

[dann2707]

Another one here that had issues with that damn aux fan! I printed off the same deflector as above and it sorted my issues.

It’s designed to be used with pla for tall and skinny parts apparently. I just sacked it off entirely with the deflector. This is on both my H2C and H2S

[goodman]

Great! Turn down/off the AUX fan also works to eliminate the corner lift issue (which mentioned by @cege and @user_1083141284 in this thread)

Kudos!

[MaxThreeD]

I went to print some small o-rings with TPU 90A yesterday. The first layer is just a couple circles for each o-ring. On the 2nd layer the aux fan kicked in at 100% and blew all the first layer lines right off the plate…

(Turned off the aux and everything printed great.)

I don’t really get how it’s supposed to work properly when one side of the print would be getting pummeled with air while the other side gets little-to-none.

-Max