Suggestions on Prototyping Rubber Part


I have a project that requires teh prototyping of one long felxible track. Imagine a small I-beam about 0.25" wide and extruded to about 2 - 3 feet long. It has to be flexible.

I was wondering if anyone could suggest how to do this and who does this kind of prototyping of a one off part?

Any tips, suggestions, and leads would be great!

Thanks for your help!

  • David

You can rapid prototype rubber type parts with Z Corp machines and Objet machines. Look for someone with one or the other.

The other option is make a mold and pour a room temperature silicone. That might offer you more control in terms of how soft the part is.

The 3’ long requirement is going to exclude you from a lot of standard RP machines.

I know that you can get stereolithography done with a soft elastomer/rubber like material but not to that length.

You might want to try finding a shop capable of making a solid master and then creating a silicon mold from that. From there… you can cast the rubber part.

Any model maker will be able to cast you a urethane part.

You won’t be able to rapid prototype anything in that length I don’t think.

You can get a two part silicone rubber kit from a company called smooth on. they are easy to use and they have ways of coloring it in multiple colors. I agree, with the idea of making a master and then creating a mold.

Agreed, I have worked on parts like this, RTV is the way to go. I don’t know what your tolerances or geometry is but I would think you are going the waste money on RP. Making the master depends on the geometry. Do a little research on what tensile strength and flexibility you need the part to be first.

Thanks everyone.

I think I can get away with making it 2 feet long or maybe 1.5 feet long, will that make any difference with my model options?

Hey MPDesigner, how flexible do you need the part… Like rubber or just slight flex? There would be other options for the latter

modelshops can mold flexible lead and other bendy materials within RTV molded rubber to adjust the flexibility.

If by flexible, you mean “not brittle” or “slightly flexible”, you could CNC from plastic stock too

Sounds like a pretty simple cross section so I would imagine making a master from MDF or other material, casting a silicone mold and pouring Urethane should be a good way to go. Alternately you could make a mold from MDF and pour the silicone for the part if you want it that flexible.

should be pretty easy.


I don’t know the details but you could possibly find what you need in production stock. Maybe you can find a pre-made master, make a mold and cast it with a material that meets your flexiblity specs.
For example check out: Plastruct I Beam Styrene 1/2 (4) #90520

an extrusion die is super cheap, you may as well go straight to a manufacturer or rp tool maker and have the real thing done. It would be around the same price.