Current Work:

• TimingBelts
  • On order from Stock Drive -- received 5/9/07
  • Maybe cast a mold/part out of silicone or polyurethane - 5/10/07
  • How to attach silicone to stuff
    • Barrett mentioned some sort of automotive glue for silicone to polyurethane?
• Actuation
  • Look for small motors
    • SmallMotors
  • Figure out how to use a motor to make two belts rotate in different directions
    • Pulleys on double-sided timing belts?
    • cable/capstan drive - REALLY hard to provide enough tension to make this work
  • Figure out how to attach a motor
    • attach it to one of the belts to create a differential
    • third belt? - inbetween other two or outside other two
  • 5/9/07 - Mark suggests having 2 small idler rollers to guide/tension timing belt
    • mount the rollers and the motor to a plate (ensure good contact and tension for the timing belt)
    • need to CAD up prototype concept (make it easily adjustible to final design after I figure out what size timing belt to use)
      • 5/15 - assembly:
        

• 5/18 - ordered parts for assembly from McMaster? : timing belts, pulleys, shaft, bearings, etc.
• 5/19, 5/20 - made wax block mold for timing belt w/ dragon skin coating
• 5/23 - poured dragon skin -- timing belt came out very nicely
• 5/24 - made new assembly drawing for first prototype
• 5/25 - machining in the PRL: turned rollers, shaft coupler, cut shafts to length, lasercammed mounting plates
• 5/28 - go to Ace and buy screws to assemble everything together
• 5/30 - discovered the U-shaped caps for holding the rollers in place
• 5/31 - everything is assembled with velcro straps to attach the device to the arm
• 6/1 - rollers need to squeeze timing belt more, need to move in towards pulley more so I made some adjustments on the drill press, cut out my timing belt mold from the wax block using a hack saw
• 6/4 - thought about how to design the two counter rotating rings prototype (Version 2)
• 6/6 - ordered 0.080" pitch timing belts and pulleys for Version 2
• 6/7 - poured dragon skin on 0.080" pitch belt (neoprene from the first order) after using silicone glue to see if it would work -- and it didn't.
• To do list
  • figure out some way to attach motor plate to arm -- does the motor need to be remote to isolate vibration effects?
    • going to try velcro
  • CAD up all the new parts, make assembly and make sure everything fits
  • pour dragon skin on wax block + timing belt
  • machine parts
  • figure out how to control motor -- maybe use Karlin's torque controller?

-- MelodyWu? - 29 May 2007