Recently, I switched from white PLA (4043A ) to black ABS. When going from PLA to ABS, it seems like the change in the extruded filament happened a lot faster than when I went back to PLA. After swtiching back to PLA, black ABS was still being extruded while printing 4 large pieces out that take up the whole bed after purging the extruder so that mostly while was coming out and printing several test pieces (single walled box and hexagon). I was wondering if others can share their tricks for switching feed. I thought that the problem with the ABS-PLA swtich is that PLA at the temperature that I was using to extrude (220-240C) is probably less viscous than ABS and so it doesn't efficiently push it out. I'm guessing that pools of ABS are being bypassed by the flow. I thought that if I had a 3 mm PTFE rod, then I can push it into the extruder after pulling out the ABS to push most of the remaining plastic at the tip out. Has anyone tried this? https://reprap.org/forum/read.php?1,77754,77754#msg-77754 Sun, 14 Jun 2026 07:00:51 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,77754,77785#msg-77785 https://reprap.org/forum/read.php?1,77754,77785#msg-77785 nophead General Mon, 21 Mar 2011 14:41:59 -0400 https://reprap.org/forum/read.php?1,77754,77772#msg-77772 https://reprap.org/forum/read.php?1,77754,77772#msg-77772
A couple of feet of filament? I probably used less than that running the tests before printing the parts so the rest came in the first few layers of the parts I needed. I guess I was being a bit of a miser. :) Luckily, I don't need these parts to look good.]]> brnrd General Mon, 21 Mar 2011 13:07:30 -0400 https://reprap.org/forum/read.php?1,77754,77760#msg-77760 https://reprap.org/forum/read.php?1,77754,77760#msg-77760
How long it takes to flush through probably depends on how long the melt zone is and the shape of it. I.e. if there are any gaps plastic can hide in it will be hard to flush it clean.]]> nophead General Mon, 21 Mar 2011 12:32:18 -0400 https://reprap.org/forum/read.php?1,77754,77754#msg-77754 https://reprap.org/forum/read.php?1,77754,77754#msg-77754
I was wondering if others can share their tricks for switching feed. I thought that the problem with the ABS-PLA swtich is that PLA at the temperature that I was using to extrude (220-240C) is probably less viscous than ABS and so it doesn't efficiently push it out. I'm guessing that pools of ABS are being bypassed by the flow. I thought that if I had a 3 mm PTFE rod, then I can push it into the extruder after pulling out the ABS to push most of the remaining plastic at the tip out. Has anyone tried this?]]> brnrd General Mon, 21 Mar 2011 11:31:36 -0400