Harbord SP rig build-2

Now for the fun of getting the energy of the rubber band released….slowly. Simon’s design uses a flat strip as the spindle, I have used a rod. This is a mistake as the rod simply spins through the putty with little resistance. As a quick fix I have filed flats on to the rod as it passes through the bearing: 

not my finest work but I’m impatient to see if it works!

 

With 20 turns of the band it will drive for 8.5 mins with about 12s per rev. It slows down to about 1rpm on the last few revs before it stops.

The rubber band is “size 84” 89mm long and 12.7mm wide.

I have discovered the motion speeds up in the warm and slows down in the cold.

Tilt is by a clothes peg wedged behind the camera and rubberbanded over the hinge.

Suspension is by ‘L’ bracket.

All up weight is 220g

Now to get it aloft and see what we get!

B

About billboyheritagesurvey

Heritage worker
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One Response to Harbord SP rig build-2

  1. Simon says:

    Lovely to see it work Bill, you done good!
    Simon

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