PET hot end jams
After a series of good PLA prints I decided to try PET. I'm running eSun PETG at 240 for the first layer and 245 after that. I ran the new filament to clean out the PLA and started a print. I immediately found that the filament feed jammed. I disassembled the hot end and cleaned it out. I started a new print at 250 but the temperature was too high. When I restarted, the filament jammed again. After a new clean out the print looks very nice so fat. However, I don't want to take apart the hot end before each print. Preheating didn't seem to help. Are there any thoughts?
Lohring Miller
Re: PET hot end jams
It's known that PLA can "char" if left in the hot end at temperature for a long time without moving. So maybe your attempt at clearing out the PLA was insufficient? PET is more forgiving of staying at temperature without moving, so you shouldn't have any more problems with it after the PLA is well and truly cleared out.
Re: PET hot end jams
I have found the best way to clean when switching between PLA and PETG is to unload/load both the PLA and PETG 220. This is towards the hot end for PLA ( I use Sunlu PLA+, prints at 205/195) and the bottom end for PETG ( I use Rigid Ink PETG, prints at 240/245). This is in the safe area for both filaments although at that temperature neither will give ideal prints on my printer. However the filament will flow well enough to load and unload.
If you still have trouble finding a common temperature for filament change use a floss filament between the active filaments.
Hopes this helps,
Martin
Martin Wolfe