Electronic shifting servo mount (cable-actuated)

This was a failed design for an electronic shifting project I was working on. It's a mount plus other stuff for a standard servo to mount to the driveside chainstay of a bike & use it to actuate the rear derailleur using a standard shift cable.

It is used in addition to the user's current RD.

We tried this with the highest torque servo we had (about 20 kgf cm, I think), & it was far too weak for a double spring old Shimano 105 rear derailleur. I think we tried with more modern long cage Sh