Cylinders, Concentricity, and Intra-layer Fusion

Hey everyone,

I’m new to the forum and 3D printing in general. I’m trying to get my lulzbot mini setup as best I can to make some cylindrical parts and I’m having problems with circularity and concentricity. When my model is a cylinder I wind up with something that is more like an ellipse at some locations. I believe that it corresponds with the two locations where the print head tends to reverse direction during printing. As a result I’m getting poor lateral adhesion within the layer simply because the bead is spaced too far out from the one next to it.

I printed this calibration model http://www.thingiverse.com/thing:24238/#files and it came out looking good using the standard HIPS profile in CURA. You’ll see it on the left in the image below.

When I print a cylindrical model I wind up with stuff like what you see in the following image. http://tinypic.com/r/5wys5j/8

Has anyone else encountered, and hopefully solved, this issue? Any assistance is much appreciated!

Your motor setscrew or belt in the direction the circle is too narrow is most likely loose or not taut enough respectively. Check them both, that should fix the issue entirely.

The X-axis belt was a bit more loose than everything else. Let’s hope that does the trick. Thanks!