Extruder screw – stuck plastic

Hi guys!
I made extruder by Dave instructions. But now I have problem with this machine. Plastic pieces don’t go to the front of tube. Everytime get stuck at behind.

If I clean tube and screw, it happens again. 🙁
Pieces are PET (shreded by Dave shredder).

See my video with problem

I don’t know where can be problem. Please help.
Thank you very much!

It says video not available. (tip: if you just put the youtube link in your post it should automatically embed it) PET is a tough one to start of with. It’s either not molten or burned, you need to have your melting temperature very accurate. I’d suggest to give it a few runs first with PP or HDPE to understand your machine and later move on to PET

Good luck! 💪

Oh really? I thought, it must move forward without heaters… Now I’m smarter.
Thank you and have a nice day!

Ah you haven’t heated it up yet? The material will move forward once it starts to melt inside. No worries, just keep building 🙂

Maybe now, video would be functional.

I try PET and HDPE (without heating elements). But every material get stuck on the start of tube.

Thank you Dave for your impressive ideas. Your machines are great!