Bit of an engineering question. If a snake robot is 100 cm long, and every 10 cm is another motor. Would the robot lift more weight, the longer/more motors attached to it.. or is lifting ability solely based on a single motor lifting.

  • $\begingroup$ Your question is not really clear. Do you want to know if the lifting strength is the sum of all motors or the strength of a single motor? $\endgroup$
    – Marco
    Commented May 12, 2017 at 8:25
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    $\begingroup$ Please make a sketch to illustrate your lifting objective $\endgroup$ Commented May 12, 2017 at 9:58
  • $\begingroup$ Can we mark the above answer as correct? Somehow posted on a different account and I am not sure how haha. Also then delete this comment. Great answer, thanks Chuck! $\endgroup$
    – Carson
    Commented May 12, 2017 at 21:48
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    $\begingroup$ Welcome to Robotics @C.Skjerdal, I'm afraid that only the account which asks a question can accept an answer, so please follow the instructions at I accidentally created two accounts; how do I merge them?. Note that moderators can't merge accounts for you. $\endgroup$
    – Mark Booth
    Commented May 15, 2017 at 8:30

1 Answer 1


Every action has an equal and opposite reaction. Each motor/joint in a linear chain of actuators (snake) needs to be capable of supplying the appropriate reaction forces.

This mean that, if you have a 100cm long snake robot with a motor every 10cm, the first/"neck" joint (at 10cm) needs to support 8 other motors and 90cm of snake body. The second joint needs to support 7 other motors and 80cm of snake. This chain continues.

So no, making it longer and/or adding more motors doesn't really help anything because you'll need to make the existing motors bigger to be able to handle extra length and new motor(s). The new motors don't "help" because they provide a reaction force/torque which just gets passed off to the next actuator.

The existing actuators wind up still "seeing" all the load forces that the new motors are trying to interact with, but now they have to carry the bonus motors in addition to the load.


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