It got clogged when printing with PLA after printing ABS

Bambu Lab H2 Series
1

Is there any good tutorial with video for beginner?
I tried to disconnect the PTFE tube at the top of the extruder but it’s stucking there and cannot pull out.

2

Here’s the official guide:

About the PTFE, take the nozzle off and try to manually work the filament cutter arm… then try the PTFE again.

1 Like
3

Thank you.
I could pull out PTFE tube however I cannot pull the filament.
It seems stucking inside.
Could you help me to solve this situation?

5

Thank you. so all I have to do is

  1. set the nozzle temp to 0 and wait until the nozzle reaches room temp.
  2. pull PTFE tube out from toolhead.
  3. set the nozzle temp to 280 and wait until it gets that hot.
  4. pull out the filament.

Is this fine???

6

When ever you go from a higher temperature filament such as ABS to a lower temperature filament like PLA, You need to purge the ABS at it’s temperature with the PLA. It clogs because the ABS left in the nozzle does not melt at PLA temperatures.

7

DO NOT PULL OUT.
PUSH IT ALL IN. WITH ANOTHER FILAMENT OR ANYTHING PUSH IT IN!

PURGE, DO NOT RETRACT.

If you pull it out you risk clogging the entire extruder which is 100 times worse. Imagine fixing the extruder on H2D lol. Because the molten plastic would be all over the place.

Just raise the temperature to 270C or even 250C would be enough, then insert lots of PLA to purge out the ABS residues. Extrude all the way, do NEVER retract before you cut.

8

So what exactly am I supposed to do before switching to PLA from ABS?

9

you should just use the printer’s unload & load feature. you should not do it yourself usually. with ams it’s 0 effort easy work.
but for now, to fix what you have already found out, you need to heat up the nozzle, to 270C or 280C, then control the extruder on your printer’s UI to extrude, then insert new filament then extrude a lot while reduce the temperature to 250C.

10

Thank you so much. It’s all solved now!
First, I set it up to get 300 temperature then I re-load filament again and again with pushing filament.

11

oh it’s not a good idea either, too hot would vaporize the filament and cause lots of issues :joy: even a boom.
anyway do not do it manually again

12

There is no need to disassemble the heat zone of the print head, you just need to extrude at the ABS temp, as a purge with the PLA

1 Like
13

like what kind of issue??
I tried it with 320 in the end. I saw smoke…

14

Thank you for an advice, sir!
If I load the filament in right extruder, it goes all procedure and it purges in the end.
However, it keeps saying the error that I have to push filament until it won’t go any further.

Why is this? So weird.
Because it extrude the filament when if it’s loaded in loading mode.