DIY Injection Molding + 3D Printing low run injection molds

Hey All,

I was wondering if anyone knew how realistic it would be to create a DIY injection molding machine and utilize a 3d printed low run injection mold to create 10-100 copies of something.

the DIY injection molding machine i’m referring to is something like this below:

With a low run 3d injection mold like the one below:



I’m interested a small diy injection machine as well, but for small runs of parts like that I’ve always used silicone molds and found a suitable urethane for just about any purpose.

I don’t know that the printed mold is feasible since we can’t do SLA (as far as I know, which isn’t much…)

Are you wanting to work with recycled plastic, or what material are you thinking?

Hey, we have a form2 SLA printer…?
I was wanting to work with recycled PET or something food grade. I’m thinking about starting on a DIY injection mold machine in the back. seems pretty simple, most of the work is just creating a base to hold the metal tube that gets super hot and melts the plastic. then hooking up the electronics to heat up the metal tube and then something to push the plastic through.

I wasn’t familiar with urethane and silicone mold casting method. This is interesting, and I think I might just follow this process as I really only need like 20 of what I’m trying to make. Thanks for the idea!

I’m still interested in making a DIY injection molding machine sometime in the future but the eurethane will work for now.

Also, are you saying creating a mold using an SLA machine might make sense? What’s wrong with the FDM machines? I’d like to use the FDM ones since they’re so much faster.

Actually no, I think the ones at the space with ABS would be good, Sometimes I forget my bias from only using makerbots with PLA before, and those parts didn’t sand well. (I usually print things, make them smooth, then silicone mold them). I think the aluminum shell-backed mold idea is good too, if you wanted to use plastic for a mold. Some plastic is quite abrasive and hard on molds. It would be great to experiment with some printed molds and a diy injector though. One interesting thing I’ve seen and was very curious about for a diy injection mold is this aluminum filled resin

Good luck with your silicone mold!

Hey all. Interesting conversation. I’m new to the space and came here with interest about injection molding techniques---- has anyone began building a DIY molder yet? Does the lab have one? I am particularly interested in elastomer molding. More specifically, conductive elastomer… Which does not seem to be a popular injection molding material

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I have a David Gingery book “Plastic Injection Molding” which has the plans to build a plastic injection molding machine using recycled plastic bottles. I googled “gingery plastic injection molding machine” and I see that brings up that book as well as information on people who have tried it.

I have never tried it, it is one of those projects that I am yet to get to.


depending on the project, look at istretch wire from mwcc embedded in elastomer
i have some samples

sweet! have you tested the conductivity of the samples?

I am investigating what is out there, and your reference is mighty helpful. From what I’ve seen so far, and for my aim, I think I either need to work with a lab like the stretch wire’s (or others I’ve spoken with) to come up with a new manufacturing technique, OR create my own. Perhaps necessity remains the mother of invention~

You might take a look at these guys if you want to build an injection molding machine

Maybe the Plastics SIG will consider some kind of injection molding equipment.

Funny you should say that, I’m envisioning building one in the future. Ive worked on some small ones. The most complicated portion is the dies.


I don’t think there’s much of a use case for an injection molding machine at the 'space.

“They” sell small injection molding machines, but they’re very limited in the size of the mold you can use in them and – hence – the size of the part you can make. The key point is that big parts require really big pressure. To make anything of decent size, you need a very expensive large machine that breaks easily.

If you have small molding jobs, Protolabs has a good reputation for dealing with “small” jobs.


conductivity is great, the metal conductors are continuous
induction may change