Best way to change from ABS to PLA?

I've been ussing abs for printing and i have a pla material to test but yesterday i took oof the abs filament, set the temperature to 260 ( that's the temp needed in my hotend to melt abs) and inserted the pla filament to get offthe excess of abs. After a little while, when allthe abs has gone out, i downloaded the temp to 200 but my nozzle-barrel got jamed.

What is the recommended procedure for this?

Thank you

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Ernesto Pareja

dcctrains.netne.net

If the jam is not too bad then you can repeatedly heat the hotend to about 185, pushing in filament, reducing temp to about 80 and yanking it out. Repeat until you can see the nipple of the orifice of the nozzle on the end of the filament.

If it's a bad jam then you're best off taking off the hotend and burning everything out. I usually use an allen key to push out the remaining plastic.

Others may have better methods. Good luck.

The procedure was correct, but it takes several meters to flush out the old filament in my experience.

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[www.hydraraptor.blogspot.com]

I agree with Nophead here...in my experience I have had ABS bits coming out in the PLA for quite a while after switching. I usually try to first get all that I can out by cooling the hotend and reheating to just where the ABS is soft enough to pull out, then I put the PLA in and run it for a couple hundred mm. Then finally I do a few calibration parts to get the ABS out as well as to get my temperature and esteps accurate.

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If your heater block can be removed easily, and you have very good ventilation, or can perform this outside, you can heat up the block on a gas stove (also, no nagging wife/mom/girlfriend), or with a torch, and burn out the ABS.

You will know it is clean when there is not orange fire or black smoke being emmitted. Use some tongs to cool it off rapidly in water, dry, and reassemble.