question about the flexible shaft

[mechanicalbrain]

https://sdp-si.com/ss/gif/SSFVRI.JPG
who used a flexible shaft and how well did it work?

[sanddrag]

FIRST used to give them in the kit with the Keyang seat motors. They worked pretty dang good on this robot in 2002
http://www.firstrobotics.uwaterloo.ca/resources/galleries/grippers/grippers38.jpg
http://firstrobotics.net/02gallery/pages/060-1_jpg.htm