sorry for the late reply, I tried looking for tutorials for things like that and all I could find were ones that used sine waves as well and made it look kind of robotic. it wasn't really what I was looking for, but I played around with things and couldn't figure out how to do what I wanted.
what I want to do is make the arm a fixed length and add a physics revolute point at the grapple point so that it swings freely, when you first grapple on I want it to send a force depending on which side you are compared to the grapple point.
the updated c3p file (disabled stuff are the failed attempts) -
https://jmp.sh/9QyQCrx