Bad_Mechanic

Yeah, sorry about that. I've been thinking about this problem for so long now that it didn't even occur to me that the prints looked different.

Sorry, yes it is. It takes 5.5 hours to print, so I generally stopped the print once I could see whether or not the pattern was there. So that picture is basically the bottom 1.5cm of the complete model.

So, this is a strange one. For the past several days I've been trying to figure out why I kept getting a strange pattern in the Z axis on my print. I tried a lot of different things from very conservative profiles with low speed and jerk settings, to the default profile, and several other recommended profiles other people recommended. I also checked the printer over physically to make sure everything was tight. When I noticed the pattern was identical regardless of the settings, I suspected it might be Cura itself doing something. I installed Slic3r and mirrored the settings as closely as I could, and the print was complete free of that pattern (see attached pictures). Right now I'm not sure how to proceed with troubleshooting this problem.

Sorry for the slow reply. The new files are attached. They should be identically aside from combing. I printed both an verified that no combing left blobs and with combing made the thumping sound. I also tried the no skin combing option, but it didn't seem to be any different from the combing option. 200_combing.gcode 200_no_combing.gcode

There's a very good chance I mixed up the files as I was doing this at midnight this morning. When I get home I'll redo my test files with combing being the only difference, run both of them to verify them, and then update this thread.

There are two gcode samples attached. They are from the same STL file, with the only different being the print temperature and combing being turned on/off. 200.gcode has combing turned off, it does not make the thumping sound when printing, but has surface blobs. 195.gcode has combing turned on, it does make the thumping sound, but does not have surface blobs. 200.gcode 195.gcode

While doing some tests and calibrations on my printer, I realized the wall thickness is thicker on curved sections of the wall, while the wall thickness is as expected on straight sections. This poses a particular issue when printing something with a hole in it, as the hole ends up being smaller than designed. It's not much, only about 0.15mm, but it's enough to sometimes be an issue. Any thoughts on why I might be seeing that?

My Ender 3 was making a very strange "thump" sound while printing. Unfortunately, the sound is quite loud and disturbs my wife. I finally figured out what it is. Right before Z moves up one layer, the table executes a very rapid and very short back back and forth movement, and it's that movement which is causing the sound. It turns out that movement is caused by combing. However, when I turn combing off, I get blobs on the surface at the Z axis transition points. I'd appreciate any help in figuring out a solution to eliminate or minimize the thumps, while also preventing surface blobs.