This color changing door handle was made using a very simple manufacturing process. [Barmak] already had experience working with polyester resins when making passive component filled drawer pulls (he included a couple of pictures at the end of his post). The same process was used here except that instead making it from one solid chunk of clear resin he decided to use alternating layers of dyed resin.
The build begins with a mold made out of MDF. This material has a very smooth surface finish which will help with the final look of the door handle. Threaded rod is inserted through carefully placed holes in the side of the mold — these will serve as the mounting hardware when complete. He then pours thin coats of resin to build up the complete handle.
An RGB LED strip is incorporated in the side of the handle that will go toward the door. It seems like the wires to control the device pass through a hollow spacer surrounding the threaded rod. He makes some mention of using a 555 timer to control the colors, but there’s not much more information than that. Still, the reflected light is a unique feature if you’ve got a place in your home that needs to be spiced up.
Once you’re done, you can use any leftover resin to make your own project boxes.