Weird start behavior

I have a custom start g code for my printer. I have it go through the standard ABL procedure then go to the front corner to finish heating up. After that it performs a wipe procedure to knock off the ooze on a wiper I have clipped to the side of the bed.

It was working great! Now all of a sudden it won't go to the corner and extrude. It moves there, heats up, but won't extrude the filament I call for it to extrude. Nothing in the code has changed that I can see. The only thing I have changed is add a print cooling fan but I fail to see how that could cause the filament not to extrude. It isn't even on.

Here is the code from my slicer...

G1 Z5 F50 ; lift nozzle
G28 ; home all axes
G29
G1 Y280 X307 F6000
G1 Z0.1 F50
M109 S[first_layer_temperature]
G90
G92 E0
G1 F50 E8
G92 E0
G1 Y100 F6000
G1 Y160 F6000
G1 Y30 F6000
G1 X280 F2000

and here is the code from a code file...
; generated by Slic3r 1.1.7 on 2015-08-27 at 09:24:35


; perimeters extrusion width = 0.40mm
; infill extrusion width = 0.67mm
; solid infill extrusion width = 0.67mm
; top infill extrusion width = 0.42mm


G21 ; set units to millimeters
M107
M190 S65 ; wait for bed temperature to be reached
; 12" i3v 3mm PLA for .40mm E3dv6
G1 Z5 F50 ; lift nozzle
G28 ; home all axes
G29
G1 Y280 X307 F6000
G1 Z0.1 F50
M109 S200
G90
G92 E0
G1 F50 E8
G92 E0
G1 Y30 F6000
G1 X280 F2000

Okay, now I am getting perturbed. On this last test print the printer did not extrude at all during the wipe procedure and then went it went to print, the ABL probe bounced up and down and the extruder just wobbled. Wasn't like skipping/missing, it just wobbled.

Quote:

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Originally Posted by tsteever

Okay, now I am getting perturbed. On this last test print the printer did not extrude at all during the wipe procedure and then went it went to print, the ABL probe bounced up and down and the extruder just wobbled. Wasn't like skipping/missing, it just wobbled.

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Hmm...that sounds like a power problem. How are you powering the servo? If it's running off the 5V regulator on the arduino, all kinds of bad things like you describe can happen.

On my RAMPS-equipped printers, I pull off the 5V power jumper, cut D1 and run two separate 5V power wires from the power supply to Vcc and +5V so they're powered separately. This has solved most of my servo twitching issues and commands that seem to abort or just not run intermittently.

You can also use servo deactivation to keep it from running at all when you're not probing.