Printer makes short stops in the print

Carl_Emil_Hoeck · May 14, 2020, 6:14pm

Problem:
Same GCODE file, different results when printing through OctoPrint and SD card (flawless when printing from SD, not so good through OctoPrint)

What I have tried
This only happens for objects sliced through the browser-based slicer "Kiri:Moto", and the creator of the slicer seems to think it's a problem with OctoPrint as well.

I am using a Creality CR-10 and an Creality Ender 3, and whilst printing through OctoPrint I was getting some big "blobs" all over every smooth curve. I tried printing the same GCODE file from the SD card, this time and it came out flawless. Then I noticed that the printer was pausing for maybe about 20 ms once in a while whilst printing.

I am now testing the printer in "safe mode" to make sure that its not due to a plugin, but last time I printed through OctoPrint, no plugins other than the standard ones were enabled, so doubt it'll make a difference.

Logs
octoprint (2).log (132.6 KB), serial.log (3.2 MB)

The GCODE in question
A good old benchy! Sliced version; https://1drv.ms/u/s!Aona7mYqOncBg_8HQMS3g_68C2vJqg?e=LwW8US

CR-10: Marlin 2.0.3 - Raspberry Pi 3B - OctoPrint running 1.3.12
Ender 3: Marlin 2.0.4.3 - Raspberry Pi 3B - OctoPrint running 1.3.12

Hope someone can help as to why this inconsistency is there when printing through OctoPrint.

Ewald_Ikemann · May 14, 2020, 6:30pm

Hello @Carl_Emil_Hoeck!

This behaviour is explained here: The ongoing USB Conspiracy Theory?

This can help: New Plugin: Anti Stutter - Need Testers

Carl_Emil_Hoeck · May 14, 2020, 6:51pm

Thanks, that was really helpful

FormerLurker · May 14, 2020, 7:07pm

I'm glad you found some use for the Arc Welder plugin, but you might want to talk to the slicer creator again and point out that an unusually high number of points are being created with distances as low as 0.0066mm between points. That is an extremely small separation, though the vast marjority of points are spaced further apart than that.

Here is an illustration of the first layer, analyzed on ncviewer.com:

Here is output for the same layer from PrusaSlicer:

Notice that there are far fewer points around curves here, though you would be hard pressed to see any difference in the output. Arc Welder will definitely improve streaming performance provided your firmware can properly handle arcs, but I think that slicer needs to be tweaked a bit still.