Swapping ABS/PLA

[richardphat 0]

Hey, quite curious, is it needed to clean the nozzle in acetone bath for 1-2 days before swapping to PLA filaments?

Or I can go straight and insert the filament to the feeder.

 

[gr5 2,069]

ABS to PLA is the tricky direction to switch. PLA to ABS is not an issue.

You need to clean out all ABS out of the feeder teeth and the bowden tube. Especially if the colors are different.

I also strongly recommend you do a cold pull when switching filaments. In fact I do this every time I even just change the color. To do a cold pull (aka atomic method) with ABS set the nozzle temp to >200C (220 is fine) and shove the filament into the nozzle good, then set the temp to 130C, wait for it to get down to 130C and then pull firmly the ABS filament out the feeder. When the filament is half way through the bowden let it cool another 10 seconds before pulling it all the way through the feeder. The resistance from the motor is small but it's best to pull it very fast as the tip goes through the feeder to reduce likelyhood that it breaks off inside the feeder.

Then also cut off the tip of the filament if you see any dirt/spots on it. This will keep your nozzle relatively clean.

 

[gr5 2,069]

Cold pull temp for PLA is 90C. ABS is around 130C if I remember right (or is it 140C?). If you can't pull it out at a given temp raise the temp by 10C steps until you can. You want a strong force - roughly 10 pounds or 5 kg.

 

[richardphat 0]

Thanks, I'll do it right away.