• Ray Edgley posted an update 1 week, 4 days ago

    Fred InMoov first video, shoulder view of Bicep rotate.

    • This video upload is in response to lorn Campbell query as how it works with the Bicep rotate.
      My recommendation for anyone wanting to do the same thing, would be to use a ribbon with more than 16 conductor and spit the extra across the power wire.
      I used 3 for the servo power 6 Volt and 3 for the servo power 0 Volt, this may not be quite enough, works ok for the wrist, fingers and bicep rotate, but might not have been good enough for the elbow as well.
      Although it was good enough for it to destroy the elbow when it went beyond the limit.

      Oh Well, back to the printer…….

    • Got to the bottom of the Elbow destruction.
      The smaller servos for the forearm were a long time in coming, so i had the larger joints all fully operational and calibrated long before the servos for the fingers arrived.
      After I installed the servos for the wrist and fingers, i neglected to re-test the elbow until yesterday, at that point the wires from the controller board located in the upper bicep to the servos turned out to be too short when the elbow was bent, this placed excessive strain on the joint which broke the plastic hing pin I was using.
      This resulted in the position pot on the elbow showing the joint had over shot the target position resulting in the servo reversing in an attempt to straighten the elbow until the piston popped the glue joint (PLA Parts) between the forearm and the elbow gear. This also continued until the piston screwed all the way out of the piston base breaking the lower arm side where it connects to the upper arm side.

      What to learn from this.
      Check the rotation of any joint after you run new wires though it over its entire travel :-)

      Really am starting to get better with plastic welding on PLA, they do say practice make perfect……
      Hope this stops someone making the same mistake I made….

    • Nice and smooth. Your print quality looks really good with no banding.

      • Looks can be deceiving, but thanks for the complement.

        The shoulder pieces are probably the best parts on the whole robot, I’m more pleased at getting the ribbon to work through the bicep gear.

        Some of the earlier pieces had real bad banding, turns out a spacer i fitted to the top of the Z axis screws to reduce the banding actually made it worse. these parts were printed after I remove the spacers that were supposed to reduce the banding.

        I’ll post some more operational videos after I finish repairing the elbow…