I have these two sets of 3 countersink bits and 3 self-centering drill bits that I wanted to store neatly in my DeWalt bit holder case. Both sets of bits use a 1/8" hex key to adjust set screws, so it made sense to have storage for the hex key along with the bits.

I went through several iterations to make sure everything fits well inside the case. The design is 3 separate pieces, but you should be able to print them in place without supports. Once it's done printing, put it into your bit case and lever the middle section up so that it can rotate to gain access to the bits.

Hardware:

8x - 6mmx2mm neo magnets