3D printing

This is a horn button surround for a 34-36 Auburn. It is made of Bakelite they came in brown and black. Would this be a good candidate for a small run, say 20 of each color? Anyone with a WAG on cost?

Since you have a good original part, it might be easier and cheaper to make resin castings. First, a silicone rubber female mold is made of your original part. Then, you cut the silicone mold in half, add holes for vents and filling in the top half, and pour in a low-viscosity polyurethane plastic resin. The resin can be dyed brown or black or any other color. The resin will harden in 15-30 minutes. Peel off the silicone rubber mold and do it again. All the fine details should come out very well. Just wipe some paint into the lettering. It should be possible to make 20 parts with one silicone rubber mold.

You might need to get some knurled threaded inserts to cast in place. Some screws from the outside surface of the mold will hold them during the pouring process. The visible surface should be in the lower half of the mold so that any bubbles will be on the back side of the finished part.

Here is a typical vendor of the silicone rubber for molding and the pourable resins and dyes:

http://www.polytek.com/products/liquid-castingmold-shell-plastics-foams/polyurethane-liquid-casting-plastics/

The Shrock Brothers make a lot of reproduction knobs and flexible rubber parts this way.

See http://www.shrockbrothers.com/studebaker_reproduction_parts.html

If you can buy small quantities of the materials, it might only cost $100-$150 for the 20 parts. A pound or so of the materials should do.

Thanks for responding Gary. We are familiar with casting urethane resin rubber parts. We actually have an account at Polytech and Tom Shrock casts a few of the more complex parts for us. The only reason I was thinking about 3D printing is to retain the Bakelite finish and there would be no shrinkage. I will discuss this with my wife, as she is the one that does all the casting. Good ideas come from a lot of ideas.

I am a lifetime member in the "National Street Machine Club". They have an article in their archives (Print Your Own Parts) concerning 3D printing parts for cars. They reference a company named "Redeye on demand" that has many material options and they have made many parts for automobiles. http://www.redeyeondemand.com/OurMaterials.aspx It looks to me like they might be able to fulfill your requirements but most likely with an ABS plastic or some other plastic based alternative (not in bakelite)

Thank you Steve, I'll check out the website.

I watched a show on one of the financial channels where the CEO of one of the major 3-D printing start-ups was interviewed. He said right up front that due to cost the future of 3-D printing was likely not in manufacturing items that could be manufactured in less expensive ways but rather in producing items that could not be made with any other technology.

Sometimes 3D printing is cheaper. Rather than spending a couple thousand dollars CNC machining a core pattern for a metal casting, you can order the sand core itself from a 3D printer for a couple hundred bucks.