I am building a quadruped with 3DOF and it currently is weighing in at 3.34 pounds and I am using the 3" femur from lynxmotion as well as the aluminum “C” Leg.The servo’s I bought not knowing were the Futaba s3004 std. servo and it is looking like its not strong enough to hold the thing up.Does anyone have a ballpark guess about how much torque I would need seeing how the 4.1 kg-cm these provide is not enough or a servo they would recommend?
Most people use Hitec HS-645MG’s for their multi-legged robots - they work very well and provide a fair amount of torque. ^___^
hitecrcd.com/products/servos/analog/premium-sport/hs-645mg.html
would you know the formula to find out the amount of torque ?
RobotShop have a really nice page on calculating servo torque for a hexapod (including the equations) by taking moments - I would assume you’d do the same thing (except you’d just take off one of the two legs on the right hand side since you’d only be balancing on two in total). ^____^
robotshop.com/blog/en/robot- … orial-3587
The torque calculator is a very good start, but efficiency is very important. You should take a look at the corresponding tutorial as well to see the assumptions. A secondary approach (since your robot weighs as much as many Lynxmotion hexapods) is to simply see which servos we use for that size robot.
I was thinking getting these for the knee and ankle and leaving the ones I have for the hips.
Hitec (#HS-5685MH)