Proper way to unload filament?

I figured this would be an easy search but turns out I was wrong. So is there a proper way to unload then reload filament without causing a jam or some other issue? FWIW I have an i2 and using ABS with what appears to be the typical Greg's Wade extruder.

I just heat my hotend to temperature, open up the spring clamp that holds the idle roller on the filament then pull it out. I have done so many times for the past 3+ years now. Once the new filament is loaded I then extrude in open air until the old color is gone.

Thanks. Figured it would be that easy but thought I'd double check before I made a mess.

I raise (or lower, depending of the initial state) the temperature a between glass and fusion temperature (160°C for ABS, 90°C for PLA) I wait few minutes to get an even temperature in the hotend, then I remove the filament manualy or mecanicaly with same results.

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Collective intelligence emerges when a group of people work together effectively. Prusa i3 Folger (A lot of the parts are wrong, boring !)

I usually just preheat the printer to the normal temps I use for prints. 230c or so. Then simply use the knob on my extruder to reverse the filament out of the bowden tube. Once unloaded I simply load the desired color and start printing. I have my spool mounted to the printer so if I move the printer the spool goes along for the ride. With ABS I have never had moisture problems so I can say its not bad.

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[engineerd3d.ddns.net]

Modicum V1 sold on e-bay user jaguarking11

I do this in pronsole:

settemp 180
reverse 20 200
reverse 400 1000

I have a bowden setup so need to reverse quite a way.

I then feed the new one in manually and extrude until the color change has completed.

This is cool. I am new to 3D printing.... Will this work if you create a file named "unloadfilament.gcode" with those three lines in it? If so it would be great to keep loaded on the SD card all the time... makes you think about the possibilities...

FWIW, on one of my printers there's no issue. On the other (also with a Chinese E3D "clone"), it seems that a blob of slightly over 1.75mm diameter forms in the melt chamber if the hot-end is left for more than a few seconds without extruding. If that blob is fairly solid, it stops the filament from retracting more than a couple of cm. Worse, if it's slightly softer, during the retraction the blob can solidify inside the PTFE liner and jam up solid. On this printer, I extrude a few cm immediately before trying to change filament. A key thing seems to be to make the first pull quick and long, so that the soft filament elongates and narrows down the blob.

When the heat block is near working temperature, I simply open the breech block and yank it out.
Slide the new filament in the hot end, press down to see it ooze out and close the breech block.
Roughly 1.5 seconds.

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Lykle
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Co-creator of the Zesty Nimble, worlds lightest Direct Drive extruder.
[zesty.tech]

A lot of techniques here, I like to heat to a cool temp for the filament loaded say 180 pla or 210 abs push manually slightly then yank it out firmly, this ensures any slightly wider plug at the nozzle which is normal 1.75mm nozzles are 2mm bore, comes out cleanly. I believe this helps to pull old filament and debris out.

I then increase to normal printing temp and push the new filament through and then extrude 100mm or so to purge. Slightly more if swapping to/from pla as this jams much more easily than abs/petg.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Quote
DjDemonD
A lot of techniques here, I like to heat to a cool temp for the filament loaded say 180 pla or 210 abs push manually slightly then yank it out firmly, this ensures any slightly wider plug at the nozzle which is normal 1.75mm nozzles are 2mm bore, comes out cleanly. I believe this helps to pull old filament and debris out.

I then increase to normal printing temp and push the new filament through and then extrude 100mm or so to purge. Slightly more if swapping to/from pla as this jams much more easily than abs/petg.

This is the method I use as well +1