Notes for Optimal Designs (page still under construction)

• Foot angle:
  • Good: angled forward is good so even with some compliance on impact the toes engage
  • Bad: pitched backward too much (the toes need to engage even in spite of some bending from impact);
• Tail extension:
  • We haven't really concluded whether or not the existence of the tail extension increases the performance of the plane, but it certainly doesn't hurt. At this point we have the extension on the first version of the dummy plane (with the simple crossed-legs design) but not on the new version (with the "knee" jointed legs). In our tests the latter has performed well enough (almost 100% generally) so it hasn't been critical that we add the extension.
  • Good: Might help engage spines if plane is pitched back too far (by torquing it forward)
  • Bad: Tail is fragile; take-off would be difficult/impossible
• Leg Design:
  • Right now we're on version 2 of leg design and it is exponentially more successful than version 1. Because it has horizontal compliance while not acting as a spring, it has no problem with horizontal velocity. We plan to add some vertical compliance at some point (right now there is only that afforded by the extension of the toes and very little in the leg itself) to increase the allowable vertical (falling) velocity.
  • Good: Horizontal and vertical compliance; joints;
  • Bad: When the legs are bent backward, they may interfere with the propeller, so we need to ensure they're far enough forward.
• Ankle Design:
  • Good: 1/8" rubber bands have good stiffness; built-in soft part around rotation rod to add damping is important; wrap the leg-ankle connection in wire before gluing to strengthen it; space for nut inside urethane ensures insignificant or zero rotation; ankle connection to foot needs to be toward the middle of the foot rather than at the back
  • Bad:
• Knee Design:
  • Good:
  • Bad:
• Foot Design:
  • Good:
  • Bad: low heels;