How do you make stuff from plastic/resins/whatever?

[luke]

You can see in picture #4 I did use wood, but not part I wanted to mold.

You could "carve" something from wood then mold it, but like magnanamus said it will need to be sealed. I simply painted the wood part of my mold to seal it, then applied a mold release to the wood.

Just keep in mind that any imperfections will be transferred to the mold, so if you don't want a wood grain in the molded peace, it must be sanded smooth the sealed so the grain doesn't raise when your pour the rubber over it.....

[Cristobal]

Most plastic parts you see every day are made by injection molding: forcing hot plastic under pressure into a pre-made mold (usually steel, but aluminum and composites are also used, depending on the application and the number of parts). Other technologies include blow molding and rotational molding, which are commonly used to make hollow parts, and thermoforming where a vacuum is used to suck a hot sheet of plastic tightly around a form.

If you don't have tools, but do have at least some money, there are lots of businesses that specialize in making short-run plastic parts.

For a couple hundred dollars you can "rapid prototype" virtually anything you can think up and draw in a CAD file. There are a number of RP technologies available, but the idea behind them is the same: the RP machine takes your CAD file and breaks it down into many many thin layers; then it forms one layer at a time, one on top of another, until you have a completed part. RP materials either are, or can imitate most commonly used injection molded plastics. Some RP machines can even make metal parts.

For a up to a few thousand dollars you can make parts from cast-urethane (typically up to about 50 parts) or make a short run of real injection molded parts using cheaper Aluminum, composite or RP-produced tooling.

A few good sites for Rapid Prototyping and Molding are listed below:

https://www.quickparts.com

https://www.protocam.com

https://www.approto.com

https://www.protomold.com

https://www.conceptual-reality.com

You may also be able to find a local small-run injection molder who can help you make a mold and cast a few parts like this guy did:

http://www.seattlerobotics.org/encoder/mar97/mold_art/molds.htm

[Rapid07]

You could also try rapid tooling companies. If you do a google search, you should find one near you!

[luke]

Holy old thread batman!