Just out of curiosity . . Would it work if I made a cast of something (like a extruder print head part) out of the water soluble filament like scafold for example. Then covered it in silicone, and when dry dissolved all of the scaffold in water. Then using the extruder inject the mould very fast? It may only work for small parts. but they would be much stronger. Or has someone already done something similar?
ok two things I see problems with How to get the plastic in fast enough without cooling and blocking? How to get the part out, since you do not have a multi part mold? One time mold? I heard that you can "bake" printed parts in an oven, , they will get stronger but they may shrink.
http://hackaday.com/2015/02/16/turning-a-3d-printer-into-an-injection-molding-machine/ Probably only good for very small parts.
Better off casting resin. Resin with iron cast here, the results are superb: http://www.3ders.org/articles/20150314-create-aged-metal-objects-by-cold-casting-your-3d-prints.html
I've done the baking thing with the coffee filament as it comes out more coffee like once baked, expect about 3-5% shrinkage, otherwise it's fine.
I remember reading a thread a while back about injection moulding, Sanjay thought it would be pretty doable with smaller parts and maybe a few Volcano blocks coupled together. The thread never really developed on it much but it has some interesting info, give it a read. https://forum.e3d-online.com/index.php?threads/injection-moulding-small-scale.315/#post-13051
