My gaming mats are 6x4 foot and I didn't want to buy new mats or put tape on my existing ones. I had an idea to make a frame to place over an existing 6x4 gaming mat to bring the size down to 44"x60". It uses 8x2mm disc magnets and needs:

4 corner pieces
10 short edge pieces
16 long edge pieces
60 8mm x 2mm magnets

By adding or subtracting the number of long edge pieces you can go to the combat patrol size or the larger game size boards.

Prints without supports, use draft settings for speed.