Hi Mr Chuck767,
Here is the updated pulley…
I repost my previous one in its entirety… as I have found that I messed up with radia&diams 😞. Thus please consider the past attached files as … digital rubbish… and treat them accordingly.
Uffff … nobody spotted it !!! 😂
Hence, we go …
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Pulley's type design requires both concurrent changes in the geometry of the mechanism's elements and their synchronized movements.
Unfortunately … in F360 Ultimate, sections of the kernel responsible for these functionalities… seem to be separate, making dynamic harmonization of the design's elements difficult (or even impossible).
However, contrary to some opinions, it is possible to perform a partial simulation of the design, limited to geometrical changes only (without pulleys rotations). It should be sufficient in many cases to properly place the pulley mechanism in a broader design context.
The not-so-good news is that, in general, even such partial simulation, CADing of pulleys will require some calculations and formulas derivations to establish respective userParameters set driving its foundation sketch, … and this might be a daunting task!
I am attaching a very basic/classic pulley design example. I hope that it is self-explanatory. Use the _Rope_Release parameter to pull/release … a rope. Unfortunately, you will not be able to 'rotate' pulley disks concurrently.

Attached files:
Pulley.f3d F3D ( 0.2MB) https://a360.co/3XH25Tr
Pulley_mono.png 4K_mono ( 1.2MB) https://a360.co/3iqnyQk
Pulley_arcd.jpg 4K_stereo ( 0.2MB) https://a360.co/3XINYwS
Pulley_mono.mp4 4K_mono (7.2MB) https://a360.co/3ATpAPw
Pulley_arcd.mp4 4K_stereo (25MB) https://a360.co/3XDZsSp
To be viewed on 4K media devices (monitors, UHD TVs, projectors...) of reasonable performance. For the best experience, use stand-alone media applications (WMP, VLC) and the native resolution 3840x2160 - full screen. The '_arcd' files require an anaglyph red/cyan glasses, while '_al' is for active shutter glasses 3D hardware (~30° viewing angle is recommended). Download the files over a network, where the cost of doing so is not a concern. The files are to be used for private, non-commercial purposes only.
Regards
MichaelT
MichaelT