before anyone goes and takes the time to make one, me and my riding buddy made just about the same exact thing, minor difference in the claws he made, bout 15 years ago, and they work great, on steel rims, as you can see he's using that on a stock rim, use that on an aluminum rim and you can forget about ever getting a seal on that bead again, we bent a .190 rim like it was paper, and by the time we realized it, it was too late.
so, be careful if you decide to make one
i personally rather just pay a shop the 15 bux to do it, if they trash the rim, they're paying for it