It was these trays that sparked the design of the entire clam jewelry box (I designed it inside out). I wanted to create a jewelry box with pivoting internal trays and what better shape could there be than a half circle (although I already have ideas for a rectangular jewelry box with similar internal design).
There were many challenges with the design of the trays. When I began drawing the parts in my CAD software program I quickly realized that the pivot point of the trays had to be as far back as possible. In fact, the pivot point had to be in the back of the box in order to eliminate gaps between the front sides of the trays and the inner walls of the box. Since this was physically impossible, I decided to use bronze bearings mounted at the back of each tray and drill a relief for them into the back wall of the box (see photos below).
This was the first time I used bronze bearings and I’m glad I did. The trays swing as if they were floating in air. It’s possible I may incorporate them in my other two pivoting designs, the trapezoid box and the helical box. One challenge I ran into was that the bronze bearings are oil-impregnated. This made it very difficult if not impossible to glue. I solved this by tapping into the bearing and screwing into it from inside the tray. I also used a dab of epoxy for extra strength (the epoxy definitely helped, but if I used it alone it would likely fail in time). The result is a surprisingly strong bearing support.
The horizontal channels in the top tray are for a unique ring holder which I came up with for this box and most likely will be used in future boxes as well. The design will allow for wider ring bands such as wedding rings as well as narrow ring bands. It will store at least 30 rings and present them all face up. When the jewelry boxes are finished I will have some detailed photos. Check back soon.