I can get bar stock but I don’t have a lathe so I’m not confident about boring the inner diameter. Concentricity on the pulleys is important because if they’re a little bit eccentric, the effective diameter is constantly changing as they spin. Plus, you need to hold a tight tolerance on the hole to get a decent fit on the shaft.
Ahhhh, right. There’s going to be a slack and not-slack side…
In that case yeah, I think I’ll see if I can build a slider into my motor mount and adjust it with a grub screw.
They’re not super beefy, I bought them mainly for precision. Rated torque is 1.27Nm, peak torque is 4.45Nm. Looks like the smallest pulley I’ll be able to stick on it is ~30mm diameter, so peak force exerted on the belt would be about 300N? I don’t see any numbers for belt stiffness though…