Changing filament size

[stienman]

This is how I currently change to a different filament size. I'd appreciate feedback if there are better ways to do this, or tricks to make it easier.
start by cutting the filament just above the pinchwheel.
1. Loosen the pinch wheel tensioner (7/64 hex) until you can wriggle the pinch wheel a little.
2. Remove the bolt and nut from the front center of the extruder mount (4mm hex, 3/8" nut).
3. Push the extruder up and backwards to remove it from the x axis, set it on the x axis bars nearby to avoid wire strain.
4. Remove the top nut of the hot end.
5. Push the hot end down and out of the bracket so you can access the entire length of it.
6. Unscrew the top and middle of the hotend from the bottom. You can separate all the pieces if you want, but it's easy enough to keep the top two pieces together and just separate the bottom from the top.
7. Heat up the hot end, and pull while it's heating up. You'll need pliers to hold the hot end so you don't burn yourself, but you can grip the Teflon tube and filament by hand.
8. The tube and filament will pull out well before the hotend as reached melting point, which is what you want since you don't want plastic leftover to prevent you from inserting the other pieces.
9. Turn off the hotend heater, wait for it to cool, and then put the other size teflon tube in and reassemble the hotend in reverse. You may need to heat up the hot end a little if you didn't remove the plastic from the tube the last time you removed it.

For future reference, here's how the plastic looks in the 3mm filament tube once removed. You can see the melt zone starts well above the tip of the hot end, which probably indicates too high a temperature from my last run. I'm still fiddling with temperatures, though, and the extruder still worked, but this doesn't seem optimal.

[img]http://i288.photobucket.com/albums/ll16 ... b51b41.jpg[/img]