After making an airless ping pong ball and pickleball, trying to match regulation weights, I set out to make an airless foosball (rather than just resize my ping pong ball). Turns out foosballs are pretty dense and heavy. I couldn't make it heavy enough, BUT it did turn out to be the best of the three as far as replacing the real thing for a couple reasons.

One - apparently the regulation size is 34.7mm. When I printed that size I noticed it was slightly smaller than the ‘real’ foosballs that we had. Turns out ours aren't regulation, but are the 36mm soccer/football looking foosballs. So now we have some regulation (well size, maybe not weight)

Two - we printed in TPU (the black one in the pictures) and PLA (the glow in the dark orange). And the TPU is so awesome - great feel and control, and bounce (I think like the regulation ones which we don't have). And the PLA has been indestructible so far because of it's density. In PLA, the ping pongs we can break if we play with them and hit hard enough, and the pickleballs in PLA don't last too long (both better in PETG and ASA).

I included scaled up sizes for the 36mm foosball, and for a ping pong size and golf ball size (although it's too heavy as a ping pong). I want to see if it explodes as a golf ball in PLA, and what it's like as a golf ball in TPU.

Here is a comparison of the cross sections of the ping pong ball design and this new dense foosball design.

PING PONG NON-DENSE DESIGN (https://makerworld.com/en/models/232540)

DENSE DESIGN