Rough Printing on overhangs on half of model only?
Hi all,
So i have a MK3 and I feel that it is printing very well except for this curious issue.
I am printing in PETG, 40% infill, .1mm. I chose a model that contained lots of circles to help ID this problem. Notice that on the bottom of the print the surface is rough on the back half of the print and perfect on the front half. The overhang is the same on the entire slice. Once the overhang disappears the rest of the print is superb and clean.
I would expect the entire slice to be rough where there is an overhang, not just 180 degrees.
If i rotate the print the rough spot rotates as well.
Any ideas on what might cause this? I have checked all the 'common print problems' but this isn't in there. Not sure what to do about it.
Re: Rough Printing on overhangs on half of model only?
2 observations:
It looks as if the feet are actually closer to the front than the back, so the overhang is less steep on the front, and the feet are supporting the surface as well (it's just a bridge between the feet in the most difficult overhang region)
Second, the cooling is said to work less efficiently on the backside, that might contribute to the roughness.
You could turn the print 180 degrees and check how that influences it.
Overall however the overhangs are amazing! such spherical shapes or a radius directly off the built plate is a really tough challenge for FDM printing and your print looks actually very good.
Re: Rough Printing on overhangs on half of model only?
Hi,
When rotating the part 180 degrees the rough spots are then on the front, and the back is smooth as silk. I think you are correct in assuming that it is the cooling. Very interesting.
I may play around with positioning a fan at the back and see if I can affect the print quality one way or another.
And yes, the accuracy and detail from the the MK3 is amazing, I am very happy in the quality of this printer.
thanks!