Cura g-code making my extruder go backwards at the start of print??

[berrybot3d 0]

Hi Guys, This is my first post! I am really liking Cura!! I have used all the others and my faviorite up to now has been KISSlicer however I am liking Cure for many reasons the main one being that is works hard not to make crossover moves all over the place. I love that!! One thing I have not figured out yet is why at the very beginning of every print my extruder runs backward about 200 mm before it starts to print. As you can imagine not good as my extruder will take forever to get re-primed. Up to now I have just been pinching the idler bearing arm to prevent the filament from moving until it stops and then let is continue as normal. This is a look at the start code Cure is generating:

;TYPE:CUSTOM

M92 E481.000000 ( The only place I can think of the I put this value in the program is under: Preferences/ Steps per E = 481??)

M140 S50.000000

M109 T0 S240.000000

T0

M190 S50.000000

; [mm] mode

G21

; absolute mode

G90

; Home

G28

; Heated bed control

M140 S<BED>

;LAYER:0

;TYPE:SKIRT

G1 X-73.494 Y-35.457 Z0.25 F3000.0

G1 X-73.4 Y-30.205 F600.0 E0.2257………………….

The thing I am not sure about is the why the M92 E481.000000 is being generated at the first line? And why that would make my extruder go backward if anything I would think It would try to extrude forward.

Thanks for the help Guys!

Werner

Designer of the BerryBot3D

YouTube: https://www.youtube.com/channel/UChZIa-t7aKDU2TE7tAuY3IA/videos

 

[gr5 899]

Does it do this *before* it gets up to temperature? If so, then I suppose it's probably the M92 command. Why not just remove this line from the gcode? I'm going to guess if you set this to zero in preferences maybe it won't show up in the gcode file?

M92 is supposed to set steps for extruder but... Are you using Marlin? Whatever you are using, I've never heard of the T0 command either. What's that do?

If you remove the first line and it still does this, try adding an M0 between every line of gcode (which should pause). That way you can figure out which line exactly is causeing the retraction.

 

[owen 17]

I can't see why it's happening but try putting a G92 E0 just after it homes