Parametric Spool Drawers

I know, I know, another spool drawer. Having finally gotten to the point that I wanted to start repurposing some empty spools, I set out to find drawers. Everything was made for a certain brand, required hardware, etc. So I decided to do an entirely 3D printed spool drawer system, that is parametric. This allows spools to be mixed and matched, brand, size, doesn't really matter.

At this point the design has only be roughly tested by myself. Everything seems to be working well, but at this point I need some feed back to keep improving.

There are 4 dimensions needed from each spool. Outer diameter needs to be fairly accurate to keep the spool centered. I found it easiest to use my calipers to measure from edge to the inner edge of the center, double that and add the diameter of the center. Inner diameter can be rounded up as this only determines the inner side of the drawer. If its too small they won't close, too big and you just lose a little space in the drawer. Spool width is best measured in the center as the discs tend to warp and give poor accuracy. 

The top spool outer diameter in the drawing must be equal to or smaller than the bottom spool. This allows you to stack smaller spools (eg 500g) on top of larger spools, but not the other way around. If stacking two of the same spool, equal measurements work for that.