Gear like pattern on some round shapes

I have a strange phenomenon with my prints: Printing at about 120mm/s there are gear shaped patterns on some round shapes. So far ONLY in more complex models. They appear on: Holes, cylinders (outside), rounded edges all in X Y, all around They do never appear on simple objects or in streight walls In an example print I put 3 objects on a plate: two cylinders and a complex object with a hole. The cylinders print perfectly round and the hole is gear shaped. Also listening to the print there is a significantly different sound with the good and the bad shapes. I'll try to video it. I use the orca slicer 1.7 and I am not sure if the slicer is to blame. It is the first slicer I use for higher flow rates. Can it be that the ratrig's RPi4 or the Octopus board bottom out processing the complex object? How would you proceed from here?
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6 Replies
beejayf
beejayfOP14mo ago
Okay - the audio is probably not helping too much. But trust me. The inner diameter print sound like there is a lot of deceleration / acceleration going on. After some research I upgraded to a RPi4 4GB and from a v10 to a v30 sd - but the geared structure remains
VisualTech48
VisualTech4814mo ago
I assume the model as well is like that Can you share the cad or a preview in the slicer prior to slicing from the to0 Top
beejayf
beejayfOP14mo ago
All three STLs should not have structured diameters. I attached the three stl files and the resulting gcode file - I designed the three files in Fusion 360 with the same export parameters (medium resolution) - funny thing is that both cylinders print perfectly round and the Proxxon adapter does not. All the other parts that are more complex than just a cylinder or so will show those gear structures on inside and outside diameters / roundings.
beejayf
beejayfOP14mo ago
The problem remains. you can literally see the print head slowing down from 112mm/s and there is a sound like an anti-lock brake (it intends to slow down fast and then speeds up again in fast sequence) during the whole curve. I am sure this "start-stop" motion causes the ripples but I am out of ideas what can cause this and how to test further.
extended-salmon
extended-salmon14mo ago
Can you see something funny in the sliced preview? If possible pls share the project file from your slicer (.3mf)
beejayf
beejayfOP14mo ago
Ha!! Found it! I checked my slicer settings against the current standard for the ratrig and found (among other small tweaks) that my jerk settings were off. (x and y 1!!) no idea how I ended up with those but setting them to 9 took care of the grear structure. Still don't know why it only showed with complex objects (that's why I did not check the slicer earlier) - but solved is solved!!

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