I just started putting together a video showing the drive mechanism operation for Bogus Batoid. I should have it posted within a week or so.
Upon first glance the drive mechanism looks much more complex than would be needed but here is what I was trying to accomplish. I had to be able to flap two large wings while alternating the angle of attack of the leading edge of the wings, into the direction of travel from a seated position, underwater. The drive had to be pedal powered from a recumbant position. It had to have a variable drive ratio since I didn’t know how much force the wings would actually require to move up and down and by changing the drive ratio I could accommodate a large range of force requirements. It had to have a method to adjust the amplitude of the wing. And finally, it had to have a method to control the angle of attack of the leading edge of the wings.
There wasn’t a whole lot of information available about this sort of drive and due to time constraints I wouldn’t be able to make major changes in time for the race so I had to design in as many adjustments as I could up front. As it was, Bogus Batoid only had a few minutes in the water before we left for the race, and this was in an inflatable swimming pool in our back yard. So inspite of not being able to tune the drive at all it still made it down the course.
So check back in a week or two to see how it was done.