Bambu studio ignoring wall speed for interior lines?

Bambu Lab Software Bambu Studio
1

I am printing an object with interior circles. I have changed the wall speeds for outer wall and inner wall to 35 and 45 mm/s, respectively. This wall speed seems to be working for the exterior walls. However, for the interior walls for the circles reads G1 F12000 for the inner and outer walls. The gcode reads as follows:

; Move to and print Inner wall of interior circle

; WIPE_END
G1 E-.04 F1800
M204 S10000
G1 X174.221 Y122.811 Z.84 F42000
G1 X155.737 Y170.64 Z.84
G1 Z.332
G1 E.8 F1800 ; this line here sets it to 30 mm/s
; Slow Down Start
; FEATURE: Inner wall
; LINE_WIDTH: 0.42
G1 F12000;_EXTRUDE_SET_SPEED ; this line here overrides
M204 S6000
G1 X Y Z E …
; print circle
; Slow Down End

; Move to and print Outer wall of interior circle

; WIPE_END
G1 E-.04 F1800
M204 S10000
G1 X157.192 Y170.825 Z.84 F42000
G1 X156.086 Y170.776 Z.84
G1 Z.332
G1 E.8 F1800 ; Again, speed set to 30 mm/s
; Slow Down Start
; FEATURE: Outer wall
; LINE_WIDTH: 0.38
G1 F12000 ; And again, speed is over ridden
M204 S5000
G1 X Y Z E …
; print circle
; Slow Down End

In contrast, the exterior walls seem to behave appropriately:

; Move to and print Inner wall of exterior object

; WIPE_END
G1 E-.04 F1800
M204 S10000
G1 X168.546 Y172.771 Z.84 F42000
G1 Z.44
G1 E.8 F1800
; FEATURE: Inner wall
; LINE_WIDTH: 0.42
G1 F2700 ; Inner wall speed correct, 45 mm/s
M204 S6000

; Move to and print Outer wall of exterior object

; WIPE_END
G1 E-.04 F1800
M204 S10000
G1 X153.527 Y185.744 Z.84 F42000
G1 X168.385 Y173.116 Z.84
G1 Z.44
G1 E.8 F1800 ;
G1 F2160 ; Some dynamic adjustments I assume, not an issue, 36 mm/s
M204 S5000

The best solution I found was setting Small perimeter threshold to 15 mm (which encompasses all my interior circles) and Small perimeter to 35 mm/s. This isn’t an obvious solution and isn’t quite practical, imo. Have I overlooked something?

Side note: I am not sure if it is related to this line of code which precedes the interior circle(s):

; OBJECT_ID: 413
; start printing object, unique label id: 413
M624 BAAAAAAAAAA=

2

Hi Ceej,

Could you post your project file, or an example that recreates the issue? I’m having trouble understanding/recreating the exact situation.

For example here’s a simple model of a cylinder completely inside a cube. They’re set to have different number of walls and infill density. I have set the wall speed settings to be the same as yours (35/45).

Here it is starting the inner wall of the inner separation between parts:

image
image1506×1365 189 KB

And here it is starting on the “outer” wall of the inner separation:

image
image1388×1358 189 KB

The g-code looks correct. But I imagine your situation isn’t as simple.

You probably know already, but that’s just the speed for that move, w/out extrusion. It’s moving to the next position (where the wall starts in this case). So I’d expect the extrusion speed to be changed before actual extrusion. Though the question of why it is setting the wrong speed in your case still remains!

Cheers,
-Max