Issue as per pictures, happens also on the diagonal limb opposite.
No other printing issue (except bridging)
Using default slicer settings for generic PETG
Printing with eSun PETG - Filament dried for 12 hours no improvement
Tried slowing print down to outer wall 60mm/s - no improvement
Tried classic wall - no improvement.
Happens every time in same place
Have recalibrated machine, cleaned carbon rods and checked belts.
Unsure what else to try, any suggestions?
To me, it just looks like a problem with not enough cooling. If I see it correctly, this part would be printed on the front right side of the printer, correct? This is an area where the aux fan does not reach, at least not well enough.
Did you try reducing the minimum layer time?
But what would be weird if it is a cooling issue is, that you do not see any problems on the smaller sections of the print below.
But given how this looks, I would not expect it to be anything motion system related. It prints the parts above and below without those artifacts. If it was the motion system, you should see it there too.
Thanks
Yes it is furthest away from the Aux fan, but I get the same problem at the opposite area diagonally across. So the back left post which is close to the Aux fan. So I’m not sure that is the only reason?
Where is the minimum layer time setting?
The first picture is the back of the opposite end
Might be fillament oozing combined with layertime?
You could change the 8 to 4 or even less and see what happens.
You can cut the model so you dont have to print the entire thing. Only the problem area and see if it is solved.
thanks for the suggestion
will give it a try!
I only now see you have a very wide model with 2 high towers.
Looking at eh model and seeing the thin parts lower down printing fine I dont think it is layer time.
Maybe it is flexing of the high towers when the printhead arrives at the model making it an inaccurate laydown of the plastic. As soon as the bridge is completed the structure gets more rigid and it prints fine again.
You could try to increase Z-hop on retractions to 1mm so it doesnt hit the towers while moving
@Chris1974
No. The opposite. You want to increase the time in order to avoid it, if it is cooling related! Decreasing might have the opposite effect!
He would want to increase the layer time, in order to slow the print down.
@tpbh
But 8s seems to be very reasonable. Can you show the sliced view at the height where the problem starts?
As @Chris1974 said, it looks like those towers are flexing. Maybe the bottom corner is starting to lift and causing the towers to flex more. Have you tried using a large brim or mouse ear discs, or else paint on some tree supports that make contact with the towers just before the issue. You could also add small a bridge (or 2) between the towers that you can cut away after.
Thanks for all these suggestions
I’ve only jest read them. This was the result when decreasing the layer time to 4s on a small version. But I totally see the issue might be flexing.
Will give brim (although model well adhered to plate) and supports a go and report back - I think this may be the answer.
I got to wondering if you could paint supports on the vertical part so I tried it with something that has a tall skinny bit sticking straight up and it worked!. Maybe this would work for your print to reduce the flexing?
I should learn to read all of the comments first!
