Unwanted Vertical Lines

I think that I am missing something obvious, but I don’t understand why my prints have the vertical lines shown in the picture below. The cylinders have too, just closer together. The belts seem tight, nothing in the extruder, and it is not the Cura settings as I tried an old g-code file (the part on the raft) shows lines. Time to take the hotend apart?


What an interesting effect, and so regular. I have no idea what’s causing it, but it is interesting.

Thanks to Mike Usrey on Facebook, the printer no longer prints with those vertical lines. He had the same issue and found that turning on Acceleration and Jerk Control resolves the issue. For his machine, he used 20 mm/s for Jerk Control and for my machine the setting works for 18 mm/s and slower (Acceleration Controls made no difference in my test prints, so I’ve left it off). Posting this in case it helps someone else.

I find it odd that this problem arose mid-spool, like something just wore out. More to learn!


An interesting solution. Showing up mid-spool certainly makes one wonder about humidity.

As it started mid spool and is so regular, I would suggest checking your belts for damage and pully grub screws. It look like a mechanical problem. Softening the jerk and acceleration may simply be disguising the problem by not whipping the mechanism around so much. Belts don’t always snap when they fail. I had one where the internal nylon threads let go which produced a stretched section which started jumping pully teeth creating weird layer offsets. Tell us when you find the culprit. Don’t think it is your hot end, too regular.

I checked the belt tension but didn’t think to look for damage or loose grub screws. Thanks! After my last post I printed a large (for my printer) ring and noticed the vertical lines still occurred despite the jerk setting. If one drew lines between opposite corners of the bed, the intersection of those lines with the circular part are where the the vertical pattern was printed. Lowering jerk a bit more fixed that. Definitely, something mechanical.