I needed to re-wrap a ton of 18650's. This jig aligns the sleeve on the cell and keeps 12 cells in order so I can bar code them after. Optionally there is a spot for a 1/4" magnet to be pressed in to help hold the cell in place.
Simply slip the sleeve over the cell and have the neg(-) end flush with the sleeve. Insert the pos(+) end in until the sleeve bottoms out. The press on the neg(-) end until it bottoms out. shrink and flip the cells and shrink.
The last pic is the processed and bar coded cells in one of my 18650 bin https://www.thingiverse.com/thing:2985831