This completed model consists of a 60mm diameter sphere in a 100mm diameter sphere
Step 1: Pasting the circle templates on card.
Step 2: Cutting the circles out.
It would have been ideal to use a circle cutter but I didn't have one.
The slots however, had to be cut individually.
Special attention had to be taken to cut the slots to precisely the right width.
too wide and the sphere would be wobbly, too narrow and the sphere would warp.
Step 3: Fixing the circles together.
This was by far the most challenging part of the sphere.
The trick was to fix all the male circles (inner circles) first and then 'wear' the female circles over them one by one.
Step 4: Completed model.
You can see here that the sphere is slightly warped.
This is because I had cut the slots too narrow.
I managed to get it right on the second attempt (picture at top).
