Home Forums General Discussion Technical Questions Undercut Drive Sheave

We have a job we picked up from Kone a few months back.The units are Northern Elevator. Kone reroped all 6 cars 6 mos ago. On a trouble call one of our route mechanics noticed the car break traction in leveling. So I went to the job today and ran each car on high speed and flipped the insp. sw. 3 of the 6 broke traction. The cars slid about 5ft. It was determined that the sheaves are worn and need to be undercut. Kone is refusing to do the work, so they are gonna pay us to do it. My question is, does anybody know a co. who will undercut on-site in the socal area. So far we haven't found one. We are looking to replace all 3 sheaves in a hurry. Thanks. Btw those 3 cars are shut down until the repair.

Seen this happen before on a job reroped with the wrong ropes. Regular lay ropes on a job that requires Lang lay will produce the same phenomenon. The Lang lay ropes produce more traction because the strands run perpendicular to the rope. Make sure they used the right ropes.

Before you cut the sheaves, balance the ropes.

In the back of the Elevator World, there is an advertisement for a guy that travels all over the US doing just that.

Guess the sheaves have no liners? Would adding sheave liners would be more affordable alternative?