[mgunlogson]

The injection probably happens faster than you think. With a high flow hot-end and 5mm deep channels its reasonable for the injection to complete in less than a second.

> How are you expecting this filament to stay as hot as the inside of your nozzle while it’s flowing through the part and touching all of those walls? How are you expecting the walls to not melt, but the melted filament to flow through them?

Specially formulated injection materials with viscosity near water at injection temps. Dual nozzle setups where PLA is injected near its breakdown temperature into a heat resistant shell like CF-Nylon or Ultem. I need people with more time and hardware to test this. This was a side project for me, out of a dozen I'm working on. And I already spent a bunch of time on it.

For a years there's been talk about doing some kind of 3D injection on the GCODE level, like Z-pinning https://github.com/OrcaSlicer/OrcaSlicer/discussions/4815 . But it was hard to experiment because slicers don't support it. Now there's a codebase with dozens of different knobs to play with.

I added support for dual nozzle printers and using a different material for the injection stage. I just don't have the hardware to test it