HOW TO Reducing PLA jams in All metal hotends (E3D)
In some cases, for some reason, you will have problem in extruding PLA on All metal Hotends (E3D Hotends). The issue seems to be that the heatbreak gets a bit too warm to the extent where the PLA will soften and a jam occurs. It appears to be a PLA only problem and it’s exacerbated by the stickiness of PLA vs ABS.
This issue can be successfully resolved in 2 ways:
- Actively cool the heat-break itself. The stock E3d cooling fan only blows over the heatsink, not the heatbreak. Here is a link to a print cooling duct that also cools the heatbreak: https://drive.google.com/folderview?id=0B73C_MyFsgfxTW53Nm9ST1l4cG8&usp=sharing
- Seasoning the internal surfaces of the hot end with cooking oil. This might sound crazy but, it work first hand with the Kraken. PLA is a sugar and molten sugars stick to bare metal like stainless steel, in the kitchen you prevent this by creating an oily patina on the metal surface by baking a thin layer of oil onto the surface. There’s some science to this but we won’t go into it here. Simply dip the end of a piece of PLA (10mm or so) in canola oil or something similar, heat the hot end to about 180 degrees and insert the oily PLA into the hot end, press it through with you fingers until it exits the nozzle then extract the oily PLA, then push 50mm of un-oiled PLA through. Repeat this as many times as you like, I had success just doing it once. The hot end will fizz and pop while you are doing this as you are effectively frying the PLA, for me (Timrastall) it smelt strongly of cooking donuts This is why you need to push an unoiled piece through to purge any excess oil.
This tip is shared by Timrastall in E3d-online Forum, read more on http://forum.e3d-online.com/viewtopic.php?f=7&t=65