Changing the filament spool

Changing filament can be done using the following steps

Remove old filament

Heat up the hot-end to standard operating temp for the plastic you are using

Remove the two M3 x 45 screws that tension the filament on the extruder

Swing open the extruder tensioner

Cut the filament just above the extruder and pull the filament out of the hot-end

Re-spool the remaining filament in the filament delivery tube

Inspect the extruder filament drive gear is clean and free of plastic debris

Insert new filament

Bevel the end of the new filament as if you were sharpening a pencil. This will help guide the new filament into the hot-end.

Insert new filament into the filament delivery tube

Guide filament into the hot-end and ensure it extrudes from the hot-end when pushing on the filament by hand

Close extruder tensioner

Insert the two M3 x 45 screws and tighten eight revolutions

Re-attached the filament cleaning pad to keep dust and debris out of the delivery tube and hot-end

Using Pronterface or Simplify3D extrude 10mm of filament at a time at 200mm/sec until you verify a consistent and smooth operation of the extruder and hot-end.

Please Note:

If you are changing to a different type of plastic filament (from PLA to ABS for example) be sure to adjust the hot-end temperature accordingly. You may need to extrude up to 100mm of filament to flush out the old plastic before printing.