• juerg posted an update 3 years, 5 months ago

    Wrist Range
    Probing my hand I I have about a 180 degrees range of turning the wrist, InMoov (depending on the used servo) about 110 degrees in my case.
    I have read through Anar’s version of a 180 degree wrist but it looks like to be a lot of detail work and probing…
    Given the range of my MG966R is about 210 degrees another solution might be to change the gear assembly?
    Looking at WristGearBigV4 I think the holes could be reduced (at least for the strings I use which are about .6 mm in diameter.
    If I could get a 1:1 gear ratio between servo and WristGearBigV4 my wrist would turn easily 180 degrees without using an external poti – and power should not be an issue for this movement.
    Anybody else been thinking about it?

    • Yes totally do-able. During my design I tested a winch servo which could rotate at 360 degree. What happens though is, more it rotates and more it pulls on the tendons.
      Though I have been recommending 0.8mm braided fish line, you certainly could reduce the holes to let your 0.6mm go through. Also I would like to mention that my first design of the WristGearBigV1 and V2 had a single pass through hole for all tendons. But when the wrist would turn the tendons would apply forces onto each other resulting having fingers stuck under the pressure of another finger’s tendon.