Very slow travel move at the start of new layer

General Discussion
1

Basic Information:

Printer Model: Custom DBOT
MCU / Printerboard: BTT Octopus Pro
Host: Pi Zero 2 w
klippy.log
klippy.log.zip (994.5 KB)

Hi all,

I am getting some pretty good result on my custom built DBot CoreXY printer (built by mashing 2x Anycubic Chiron’s together).

Travels moves are running 300mm/s @ 12,000mm/s² acceleration. But (possibly once per layer) I am getting a single very slow (looks like maybe 10mm/s) travel move and I am not sure why.

I was wondering if anyone had any ideas? Seems to do it on everything I have printed, could this be slicer related (I am using Orca slicer)?

Any help really appreciated!
…

2

The first thing I’d do it take a look at the gcode and figure out what the slicer is telling the printer to do.

3

OK, so I have sliced a smaller file with 2 objects and watched it. Looks like the slow travel move is happening at the start of a new layer, EG:

G1 X110.666 Y176.177 E.03131
G1 X108.878 Y174.389 E.09352
; stop printing object Straight 5 id:23 copy 0
;LAYER_CHANGE
;Z:0.9
;HEIGHT:0.15
;BEFORE_LAYER_CHANGE
;0.9
G92 E0

G1 E-.5 F1800
;AFTER_LAYER_CHANGE
;0.9
;_SET_FAN_SPEED_CHANGING_LAYER
; printing object Straight 6 id:12491 copy 0
SET_VELOCITY_LIMIT ACCEL=12000 ACCEL_TO_DECEL=6000
G17
G3 Z1.15 I.334 J1.17 P1  F24000
G1 X301.292 Y119.476 Z1.15
G1 Z.9
G1 E.5 F1800

The problem line appears to be:

G1 X301.292 Y119.476 Z1.15

In OrcaSlicer, the “before layer change gcode” only resets extrusion length: G92 E0

The only other settings I can think might be problems are “retract on layer change” or “auto z-hop”?

4

The issue rather seems to be that you have arcs enabled in the slicer but not in Klipper.
My vote would be to disable it in the slicer, but if you feel like then enable it in Klipper.