> McMaster Carr has sheaves. You can get them with bronze or
> even sealed ball bearings. For the 1/4" cable, they are only
> 2" diameter however.
I would be very concerned about using 2" diameter sheaves for 1/4" wire
rope. It's been a little while since I researched it, but I believe the
minimum recommended size is around 4.5" or 5" for 1/4" wire rope.
There is an email in the archives
where someone replaced 3/16" wire rope on a crank-up with 1/4" wire rope.
The 1/4" wire rope failed prematurely (after a year or two). He examined the
failed wire rope in a lab and determined it had been prematurely weakened by
running over pulleys/sheaves that were too small.
TowerTalk mailing list