For 3d Printing Nerds. – This is how you might manually edit your GCode to add in a pause at a specific layer – very useful if you want to manually change filament at a specific height within a print (for multi-colour prints when using a single extruder).
;LAYER:PAUSE
;TYPE:CUSTOM
M83
G1 E-5.000000 F6000
G1 X0.000000 Y0.000000 F9000
M0
G1 E5.000000 F6000
G1 E-5.000000 F6000
M82
A good GCODE reference is: http://reprap.org/wiki/G-code
Suggested GCODE for a blob at the start:
G0 X25 Y25 Z2 F6000 ; Go to the left front corner
G92 E0 ; zero the extruded length
G1 F200 E20 ; Drop a blob
G0 X40 Y40 Z2 F6000 ; Move head away from blob
G92 E0 ; zero the extruded length again
G1 Z15.0 F6000 ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E3 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again