Sometimes we approach a project with high expectations. We see the challenge and love it. Then, we don’t quite know what we got ourselves into. In this case, the client needed a Compact Florescent Light bulb (CFL) enlarged for a trade show exhibit. Simple enough. Except, what should have been a texbook enlargement got very, very trick at scale. The coils on the original CFL are very close together, and wind around each other all the way to the base, without touching. They are of course rigid as they are made of glass. We initially tried a flexible construction as the light didn’t actually need to function in this case, and soft foam in instances like this can be easier to work with. The weight of the foam caused the coils to distort and deform. That wasn’t going to work. So we tried copper tubing down the center of the foam to help keep the form. This proved to not only be heavy, but did not retain the shape as well as we had hoped and getting the spacing exactly right by hand proved to be difficult. One of the guys helping with this project wanted to try heating PVC pipe until soft then bending it into a coil. PVC is tricky because once it’s hot enough to melt, its a degree or two away from becoming flimsy goop. Impossible to shape. We could not get the clean uniform shape.
This project proved to be more troublesome than it appeared. We finally figured out a method that was acceptable. And vowed never to do this sort of thing again! (without substantially raising the bid). We have done several more CFL’s for this client, but were able to make a compromise. We now stack the light bulbs so they are touching. We also brought the size down to something more manageable for workers at the show. This made them easy to machine with our CNC machine. And we were able to bring the cost down which the client liked. So it was a win-win. We do a lot of those around here.