Magnetic miniature movement tray
A movement tray lets you slide a whole unit of miniatures across the board in one motion. For 25 mm round bases in a five by two formation the tray measures about 132 x 57 mm with 1 mm gaps between bases, a 2 mm floor, and a 3 mm rim around the outside. Recesses of 0.5 mm under each base position keep the models from drifting, and a 6 x 2 mm magnet pocket per slot pairs with steel washers on the bases.
Every army uses a different base size and unit count, so a downloaded tray rarely fits. With SpeakCAD you type the base diameter, formation and gap you want and get a tray sized precisely to it. Iterate on rim height in the chat and try it free in the browser.
Design a movement tray for ten 25 mm round bases arranged five by two with 1 mm spacing, a 2 mm floor, 3 mm rim 4 mm tall, 0.5 mm deep base recesses, and a 6 mm diameter 2 mm deep magnet pocket under each position.