As a product development company, we get involved with every aspect of a design: how to produce items that meet performance and visual requirements while staying within a set budget. Part of the fun developing products is playing with various processes to achieve a set goal. In my career, I have had the opportunity to design plastic and elastomeric parts that were injection molded, vacuum and or thermally formed, urethane cast, cut, bent, and 3D printed (polyjet, SLA, SLS, FDM). I have also worked with sheetmetal bending, plasma cutting, spun parts, die casting, investment/lost wax casting, EDM, wire EDM, machining, milling, turning, welding (MIG, TIG), metal printing, and stamping various metals and alloys. One process I had never had the opportunity to work with is sand casting… until now. Here’s how it happened.
While I don’t consider myself an absent-minded scientist, I do have a very bad habit of leaving my glasses in odd places, and then having to search for them. My loving kids decided to solve my problem (I guess problem solving is in their genes!) and bought me a handmade wooden nose to put my glasses on.
Problem solved! Well, at home anyway. To solve the same problem at the office, I decided to make another nose myself, this time using some of the tools at RPM Tech. The base was pretty simple, but the nose was more complicated. While I have been solid modeling in CAD for over 30 years, surfacing is not my forte. After a few trials, I managed to model something that was not too different from the wood design, and generally pleasing.
I printed a couple of parts, adjusted the shape a bit to make it more functional, and printed some more. The nose is SLA printed and the base is FDM. The parts looked pretty good and worked great. No more lost glasses!
But wait, there’s more! While cool looking and functional, I wanted to try for something a little more elegant. That’s about the time I met Bob Eagan, grandson of the American Alloy Foundry founder, based in Baltimore. He took the SLA printed nose and made a sand cast from it, pouring bronze in the resulting negative mold. The result was a rough bronze nose that was very similar (though not identical) to the printed model.
Michael in the model shop used our CNC to machine a much cleaner base out of aluminum. Then there was extensive cleaning and polishing of the nose, and the result was outstanding.
The transition from wood to bronze is interesting. We could have used the wood directly for casting pattern, but that would have been too easy…
I no longer look for my glasses at home, or in the office. It’s all in – or on – the nose… I suppose. (Cyrus Etemad-Moghadam – President & Founder, and eternal nerd)
#marylandmanufacturing #rpmtech #rapidprototyping
