I am attempting to design a 3 prong robotic claw for a robotic arm I am working on. I am planning to use sg90 servo motors, but I can't get my current design to work. My current layout is to use one servo motor on a pulley system. The servo motor rotates, which pulls fishing line connected to the end of the claw arms. This is supposed to pull the claws inward(as it does in theory), but the servo motor isn't strong enough to close it fully, and I don't have enough space in the head of claw to fit a larger servo motor inside of it. Is there a different gear system I could use to operate the arms?
You're probably going to need to use a different gear ratio to get the amount of torque you want. You'll get more torque, but the hand won't be able to close as fast. Learn more about gear ratios here.