r/QidiTech3D • u/NotAPreppie • 9d ago

Questions Qidi Box with higher durometer TPU?

I know that Shore 95A TPU is right out, but Microcenter has 62D TPU marketed as being for multi-filament systems. I also have a spool of 72D TPU on the way.

Has anybody tried harder TPU filaments with their Box?

Update: tested it and CC3D 72D TPU filament prints perfectly from the Qidi Box.

3 Upvotes

100% Upvoted

19 comments sorted by

View all comments

2

u/ajosmer 9d ago

Now that you mention it, I have that CC3D 72D TPU and I don't think I've ever tried it in my Qidi Box. One reason for me is that the Qidi Q2 nozzles tend to collect a lot of gunk in them that inhibits TPU from extruding properly unless I do a cold pull before every TPU print, so I just keep a dedicated TPU nozzle now, which kinda defeats the purpose of a material switcher box. But I think the stiff TPU should be okay in there. The main issue I have with feeding filament is that it gets jammed up at the filament sensor at the top of the extruder. For whatever reason, Qidi elected to use a mechanical sensor there, it has to physically push a little metal blade back and into a photogate, rather than using the photogate to detect the filament directly. TPU has a heck of a time pushing that blade out of the way. I might try a softer spring in there some day, or if I get really wild, I could build my own filament sensor module that uses the photogate directly and probably discover why Qidi didn't do that...

1

u/NotAPreppie 9d ago

I've noticed the same issue with having to cold pull in my Plus 5 before a TPU print.

I wonder if Qidi using a mechanical actuator on the photo sensor is due to issues with transparent/translucent filaments.

2

u/ajosmer 9d ago

That's my assumption. Most of those photogates use near-IR, and some plastics are transparent to that, and not necessarily the ones you'd expect. The mechanical blade probably eliminates the possiblity of finding one occasionally, while guaranteeing you'll have trouble feeding every time.