How to let a belt-cable disengage from a pulley?

Hi,

I would like to have a cable in my model that can engage and disengage from the pulley.

Just like what happens with the rear cable of the crane in this video at 0:17: https://www.youtube.com/watch?v=UMFlijN3dHM

Is this possible?

Answer 1

[Steve Miller]

Hi J,

The Pulley block in Simscape Multibody through R2021a will not permit the cable to disengage the pulley. It must always be wrapped around at least part of it.

One thing you could try - have the cable wrap all the way around the pulley (about 360 degrees), and permit the pulley attachment point to slide on a prismatic joint with the joint limits defined. As shown in the video you cited above, during the first part the pulley will slide to be along the direct line between the upper attachment point and ground. During the second part, when the cable should engage, lock the Prismatic Joint which lets the pulley attachment point slide. Joint limits may be sufficient for this effect.

--Steve