Precious Plastic Oslo (WIP)
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…
My 1st CNC’d aluminium mold (Imac stands makes very milling-friendly Alloy), very satisfying test got me to improve the machine before pushing further…
Waiting to assemble the shredder I’m using plastic flakes from the Bazar and occasionally some don’t-try-this-at-home electric planer in a box to shred objects.
I’ve been mostly pressing PP so far and it shrunk a lot on thick parts.
Simple molds made from geometric parts, works fine for simple shapes…
One 3D mold also made by siemen to do the firsts tests on the flute
A few examples…
A few shots of the new machine in the making
Those are great results.
I used an arbor press to provide the injection force in my DIY configuration. It works very well. http://onearmy.world/community/forums/topic/portable-desktop-injection-machine/page/3/
Thanks for posting, looking forward to how your improvements work out.
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