Weird (and unwanted) move by slicer on cylinder
Odd situation that recently started happening. I am always tweaking various profiles so it's entirely possible I have accidentally created this issue. But I am hoping that I can describe it well enough that one of you might help me understand what is causing this and how to fix it.
1) This may happen on something other than cylinders, but I have noticed it when printing cylinders in particular. The photo I have attached is based on the simplest replicateable version I could make: a small hollow cylinder that is just two perimeters thick. I've (unfortunately) seen this on "real" prints but made this sample just so you guys can see it a bit more clearly. I have a video but it's too big to post :-(.
2) The PrusaSlicer does not show these weird "extra moves". Even when I turn on a lot of the extra options and step through it, the preview is not showing them. But they nevertheless happen when I print.
3) During these "extra moves" there are no retractions or detractions. As you can see in the video, it starts to extrude the first (of two) perimeters from the back (because I have 'rear' seam alignment) and when it comes 180 degrees to the front, it pauses, makes an unneeded move towards the center of the cylinder (maybe 5mm or so?) returns to the original position and finishes the perimeter. It doesn't seem to do this 'extra move' on the second perimeter.
This is annoying as in the end I have extra material on the inside of the models. If it's solid, then you wouldn't see it. But when it is hollow (like this example model) then there is an annoying 'flash' inside that isn't just wispy stringing that can be hit with a heat gun. It's enough plastic residue that it requires dedicated sanding and Dremeling to regain a smooth inner surface.
Any help would be appreciated. I have tried in vain to adjust various slicer options to get rid of this behavior but so far nothing has worked. Hoping you guys will see the photo and my description and may know what might be going on.
Thanks in advance
Best Answer by Neophyl:
First thing I would rule out is octoprint, print from the sd cad with the same gcode that is giving you the issue. It’s really common for these types of issues, updates to octoprint or one of its plug in etc. it’s often things like octolapse for example. That moves the bed to the same spot each layer and activates a camera snapshot. Seen this before. If it doesn’t happen from the sd card then it’s a case of disabling all the extras and printing and adding them back in a bit at a time to see which one is causing it.
RE:
Added cut-down video to fit in the size restrictions
RE:
What printer and setup are you using ? Are you using anything like octoprint for instance ?
Also if you save you project file (file >save project as ) and then zip up the 3mf file created and attach it here we can see all the settings, as well as generate the previews ourselves. Best way of debugging something.
RE:
MK3S. Yes, I use Octoprint. Latest version of PrusaSlicer. Been using this setup for years. But something changed recently (maybe it was me!) and now I am getting these 'extra moves'.
I'll work to get the ZIP constructed and uploaded this evening after work. Good idea. Thanks.
RE:
First thing I would rule out is octoprint, print from the sd cad with the same gcode that is giving you the issue. It’s really common for these types of issues, updates to octoprint or one of its plug in etc. it’s often things like octolapse for example. That moves the bed to the same spot each layer and activates a camera snapshot. Seen this before. If it doesn’t happen from the sd card then it’s a case of disabling all the extras and printing and adding them back in a bit at a time to see which one is causing it.
RE: Weird (and unwanted) move by slicer on cylinder
Nice post Neophyl. I printed from SD card...no weird moves. I then went into Octoprint and disabled both Octolapse and the built-in Timelapse function. Printed from Octoprint and the print was fine this time without the weird moves.
So...does seem like a Timelapse or Octolapse issue. Not sure if recently I turned on a new option with the timelapse or if perhaps a recent plugin update changed something. But I'll do as you wisely suggested and just tweak one setting at a time until I find the offending setting.
Looks like I am good now. Thanks again!