Has anyone done lost abs/pla injection mold casting? It seems logical. Design a mold, print the mold, vapor smooth the part volume, cast the mold in aluminum, do some cleanup.
You could have an injection mold made in a few hours. If it has been done I have not seen it.
Name your printer at >$1000 + >$1000 smelting setup + >$1000 injection mold = cost of a medium sized dye set. I linked to a cheap injector for small parts for reference.
Very tricky as you may need lots of time cleaning the mold. Thats why wax is preferable as a former.
They problem would be the carbonisation of the plastic messing up the surface.
You could print the part make a latex mold, then make a wax part from the mold. Lot more cost effective.
I’ve got a memory of someone doing it for short runs. Might be false though… little late here 
Saw something here about 6 months ago, Backyard aluminum casting with PLA model, sand cast, fired to drain PLA, then cast.
Google/Youtube “Lost Plastic Casting” i’ve considered it. Seems like i heard 1200F is key burnout temp. People are making their own investment material as well as crucibles nowdays.
Yes, but specifically making injection mold dyes, I have seen lost pla casting of parts.
The main reason I am asking is to see if there is prior art, really I would like to guarantee prior art, but we will see.
I don’t have a space to safely do this atm.
There is tons of prior art., whats to patent? The process of lost (fill in
the blank) is the history.
I will be doing lost plastic casting in aluminum as soon as any one of my printers arrive and are ready for prime time. I built my foundry and have made about 2 dozen aluminum metal mini-muffin ingots from melted soda cans and such. However, I have not completed making the mold of a real usable part yet. I am not yet interested in any injection molded stuff ATM. But please keep us posted if you do go down the plastic -> metal path, as I’d like to know what works and what doesn’t too. BTW: Using the flux and degasser additives gave better results for my ingots quality.
Theres a thread on it in here about a year ago… possibly look for Lost-wax casting (also called “investment casting”,
There’s more 3D print stuff on my website… HERE:
Basically a collection of notes of interest to me
@Joshua_D_Johnson I dont like Lost (*) casting in most cases, but my thoughts are if you were to print molds, then do a wax cast of the part, make some tweeks, re-print, recast, more tweeks, then you can arive to cavity mold, use the printed cavity molds, to make a aluminim dye set. This would bring your from digital to mold much more quickly then machining.
@Tony_Hine_Nifty_Acce I have seen that post. my interest is in casting dyes for injection molding. my thoughts are print 1 dye set for a chess piece, then injection mold the chess pieces rather then printing 500 sets.
Why not just print it in wax the first time? Correct me if I’m wrong but the major reason for printing in plastic is to make the part durable.
@Damian_Poirier because wax isn’t a thermoplastic, it doesn’t have a semi solid transition region. That and printing takes many hours, injection molding takes second.