Aluminum taper-lock HTD pulleys

[Oblarg]

So, a couple weeks ago I found a very peculiar HTD belt pulley lying around in a box in our back room.

It was a standard aluminum HTD 5M-15 pulley, except it had a peculiar bore - the bore was a tapered insert with two screw holes, one threaded on the insert and one on the pulley. Inserting a bolt into one of these holes and tightening would either pull the insert into the pulley, tightening it onto the shaft, or push it out, releasing it.

After some searching, I have found that these are called "taper-lock bushings."

This is extremely convenient (the lone one I found was used on a prototype that very day), and I would love to buy more of these. Unfortunately, suppliers seem to be few and far-between and I can't find a single supplier that sells them in aluminum. This is odd, because the one I found is aluminum so someone must make/sell them.

Does anyone know a supplier for these? It'd be a great help.

As an aside, I'm frustrated that in 9 years of working with this team I had never before seen this thing, since it wasn't purchased during my tenure on the team and thus must have been lying around for all this time. What I'd give to have known these exist 9 years ago...