Gcode to extrude without USB

[Mike B]

I would like to run without any USB connection and needed to be able to extrude from SD card, so I created a couple of gcode files and am having a little bit of trouble.

I used G1 E10 F120

to extrude 10mm and it works occasionally, other times the extruder never turns and every once in a while it will retract!

During troubleshooting with Repetier Host I used the gcode tool and entered the line above and it also sometimes works, doesn't, or retracts.

Any ideas on what could be causing this?

Thanks,

Mike

[guanu]

if you want it to be consistant, make your gcode this:

G92 E0
G1 E10 F120
G92 E0

the first line sets the machine so extruder is at 0, the reason its inconsistent is if its already at 10, it wont move, if its at 0 it will move 10, if its at 20, it will retract 10... hope this makes sense!
the last line resets it to 0... you can never have too many g92s to set location! =)

Guanu

[Mike B]

Ah, that makes perfect sense! Thanks so much!!