Bulging when the nozzle makes a sharp turn

I am trying to dial my TAZ 6 for about a week now and there is two things I can’t seem two fix small ridging on the walls and bulging when the nozzle takes a sharp turn. I will leave the ridging issue for another post but here is a good example of the bulging issue:

I am slicing with simplify3D at a .2mm layer height and both prints printed 4 layers before I canceled the print so you can ignore the extra extrusion found at the top left of each corner as that is just the extruder stopping mid print and pulling off the print.

But if you look at the right print you can see a little bulging near the inside of the perimeter wall as the nozzle turns to make another diagonal line across the middle of the print. I didn’t think much of it but then when I changed the internal fill pattern from Rectilinear to Concentric I really noticed the bulging as it made this X shape bulging at each bend as it prints a bunch of squares till it fills in the middle.

I have played with so many settings, calibrated the hardware to the best of my abilities and googled around with little to no luck and getting a flat print.

I don’t think it is an over extrusion issue because I still saw it happen when I set the extrusion multiplier to 85% and you could see gaps between the line but still would see bulging on the corners.

Has anyone see this before and has some thoughts?

There’s an infill overlap setting in S3D that might help. Could also try a .2mm for the Coast setting…

Thanks kcchen_00 I gave both setting a shot but still no luck :frowning: Still testing random settings that might have some effect but the search goes on.

Hmm… well, its not affecting the exterior finish. I wouldn’t be so concerned about it. If you’re using 100% infill, the build-up could be a problem. At a normal 50% - 75%, the build-up shouldn’t be a problem. Can you post a factory file from S3D?

It really looks like overextrusion, but you mentioned you tried a 85% multiplier with no difference… what’s your underspeed percentage for solid infill?

You hit the head on nail, I thought I covered testing speed but I must have done that before I found the Concentric fill pattern. I changed the default print speed setting to 1000 at first from the default 3600 mm/min.

I could tell instantly the corners were looking way better so then I set it back to default and started to play with your suggestion of looking at the under speed percentage for solid infill. I cranked it down from 80% to 30% and it was about as much as I wanted to tolerate. Here is the results:

From left to right: Default print speed 1000, Under Speed Percentage 30%, Under Speed Percentage 80%

Thanks for your help kcchen_00 for your help! Now I just need to figure out my walls but I will save that for another post.