Belt drive and Crank Slider Combined

Sun, 10 Oct 2010


I've been experimenting with the crank slider mechanism today. 

I think I mentioned before that one of the problems with using push rods to drive wings up and down is that the effective range of movement is only around 90 degrees. If you want to get closer to 180 degrees you need to use a different technique. 

In the belt bot model I used a paper belt drive to move the arms the result was a range of movement close to 180 degrees. I thought I'd try the same technique but this time connected to a crank slider model. 

This is my second draft. 

There are two pulleys at the top of the shaft, each connected to a paper belt. The pulleys are fixed to the top of an extended slider tube. The belts are glued, through a cut out in the side of the slider tube, to the main push rod. As the crank is turned the main push rod goes up and down pulling the belts back and forth. This turns the pulleys and flaps the wings. It'll all be much clearer when I've made a model for you to try out! 

At the moment the wing still only moves about ninety degrees but by making the pulley smaller in diameter I should be able to fix that. I'll see if I can get a completed prototype up for you to try in the next day or so. I like the pulleys and belts, they give a nice Heath Robinson/Steam Punk look!