Finally sharing some of our machines and tests. I made a first injection machine based on PP design and tested it with different molds made out of steel and aluminium. Even got to test it with a fairly complex 3 parts mold for a flute made by @siemenc. I am now making a more compact-bench injection machine to focus on CNC’d molds for small items.

The first things I’m trying to improve from my first machine are :
– tolerance between piston and barrel, my last one was very loose since i couldn’t find a seamless tube matching the piping system dimensions in Norway.
– Nozzle-Mold connection, I’m trying a clamping system instead of a screwing one, time and volume consuming. I will try a “nipple nozzle nut” tip that should fit in the chamfered hole of the mold once clamped in position.
– The pressure provider, still working with the lever but I want to change for a more linear system, ideally a rack and pinion system like on a press drill.
– Insulation of the barrel nozzle, I had some weird results when working in windy locations, maybe losing some precious degrees too fast…

I also found some inspiration from “The secrets of building a plastic injection machine” book by V. Gingery to build the bench version.
The new barrel I made is from a solid aluminium rod, lathed down to fit the heating elements, ended up much thicker than the original tube, so now the body should absorb and store more heat. I also decided to use only one temperature controller and 3 heating elements, since the nozzle is not so big I felt i didn’t need it…
I’m curious about the consequences. The machine is almost ready for testing as I write…