3d prints come up with ribbing on one side

5

The right side of my prints always have the standard ribbing effect given by a bent z rod, however I have replaced the rod and there was no change. Here are pictures of one of my more recent prints: and the left side of that same print: As you can see the left is almost unaffected the right is the only side with the error. Anyone have any ideas about this?

blah42

Posted 2017-01-09T03:42:51.423

Reputation: 53

Looks like your axes still aren't quite aligned properly. What speed is your extruder moving at when doing shells? – Diesel – 2017-01-09T13:59:48.310

Answers

6

Hmmmm In my experience when a printer has that bad of wobble it is still the Z axis. Your rods might be good, but are the two Z axis the exact correct distance and equal distance on the printer frame? Imagine that you had one a few millimeters too far out. How might the rods act? Mayhaps, over the course of several layers, they would slowly drift back and forth? Creating a period effect on your print? What do the top of the rods do over time? Do they move a lot if you go from height 0 to 100mm on z?

I have a few ideas. What happens if you loosen you Z motors so they can move around their mount? I had to do that on my Prusa back in the day. I think for that machine the Belt was actually too tight causing the issue. Current printers are usually better designed so its unlikely that is your issue. Also measure the distance between the top of the rods when the carriage is at 0, and at max. You should see very little variance.

If it was on both sides I would say it was bad PID calibration. IE this simplify 3d link

Though you can see on this forum the fellow had a bad coupler. So still mechanical.

Also could be back lash / belt lash.. but unlikely

StarWind0

Posted 2017-01-09T03:42:51.423

Reputation: 2 913

+1 hit most of the points I was about to comment for. Any idea if the machine uses a worm gear or some sort of nut? Is it possible that a nut would not be concentric or be cross-threaded? – tbm0115 – 2017-01-09T15:06:44.013

Thanks @tbm0115! Yes photos of the machine would likely help as well. – StarWind0 – 2017-01-09T15:52:45.380

hey thanks it was the z axis coupling, just had to readjust it, thank you so much. – blah42 – 2017-01-10T05:40:34.163