Making your own beach ball bat is a super simple task if you have access to a cnc. But even with a band saw or a scroll saw it's not very complicated. The design however is a little more challenging than it looks. I changed mine from the standards circle shape to a more oval form giving it a streamlined look. Depending on your personal taste, there are two variations for the handle: one is completely symmetric and the other features recesses for the digits on the grip. The dowels in the grip simplify the alignment but I added them mainly for cosmetic reasons.
The build is super simple: put some 6 mm birch ply on the machine and cut with a suitable end mill (I used a 1.5 mm spiral toothed cutter). Then glue on the two handle shells. After the glue is dried I used a little hand-held router to round the grip.
Keep in mind that the stl is for 3-d-viewing only.
Visit https://www.zenziwerken.de/en/ for more interesting designs.