Have you ever been outside in the late summer, enjoying the season or working on a project, when suddenly you feel a change in the air? A shift: subtle and undefined, but definite despite the fact that you cannot put your finger on what just happened. I have. I have felt the moment when summer changed to autumn. I bring this up, because in mid December I felt the same sort of change in my life.
Now, here it is, almost the Twelfth Night, the celebration of the Epiphany, and I am seeing the effects of that subtle change. I am a gym member. My career has traction. I have- and I hate to say this- resolution.
The last year was a hard one. I did a lot, suffered more than I care to at the hands of selfish people, and lost my way... heartbreak, you could say, is a bitch. But, I have always identified with the phoenix. From ashes comes glory. Of course the flip side to that: the trouble with being a phoenix, is that every so often you have to burn. I think I'm rising.
There is pain in the forecast, but also glory and opportunity. I have made some interesting progress in the area of propulsion. I have thrown my hat in the ring. I have begun again. Within a week or so I should have some images to put up, but for now, let's talk about boats.
My recent discovery was in the area of speed. I have been pondering the question of how a prop moves a power boat faster than a paddler. It seems obvious: it's the prop. But I am not sure that is true. I think it is the prop speed. An engine can turn a prop at a fast and consistent speed and, as long as the prop keeps turning, the boat is fast. If you have ever run an outboard, and you let off on the throttle, you feel the water take effect as all the friction of the wetted surface pulls you to a stop. So, then, why aren't pedal powered boats- which use a prop for propulsion- faster?
It's two things:
1) The hulls are not designed for speed. I have been looking and they are really more about recreation. Nothing wrong with that, but they won't win if they are not designed to win. I know this, and have accounted for it by working on a faster hull.
2) The props are slow.
The second part is the revelation. Human beings are not that strong. We are something like a third of a horse power. As a result, we are not able to make a prop spin as fast as a small outboard. But, we have in our favor one thing: brains. We can overcome our limitations if we devote enough of our minds to the problem. In my case, I think I have found a way to use mechanical advantage to make my prop spin at high speeds. I don't have any pictures since it is still being worked out and I am not in my shop to make a model, but essentially, it is a derailleur.
I know: they have been around and it's not a revelation. True. But, I couldn't use one on my boat. The reason for this is that a bicycle has a long run of chain in which to deflect so that one big gear in the front can power a range in the back. In my boat, the input and output shafts are too close together to handle that. There is not enough room for deflection, so I wouldn't be able to use a bicycle set-up. But I could use a system like a drill press.
Imagine that two gears like the one above are placed in this orientation.
In a drill press, there are two sets of pulleys. They are sort of conical as each pulley set is in an ascending or descending order. These two cones are opposite to one another so that the smaller pulley of one is coplanar with the larger of the other, and so on. So, if you think of the gears on your bike's rear wheel and imagine another set of gears set next to it but reversed, you would be able (in theory, at least) to move the chain from one ratio to the next with almost no deflection.
If I lost you back there, I'm sorry. I am trying to put this down so it makes sense, but since I have only messed around with the idea and done no drawings, I can't explain it that well. The long and short of it is this: if I can do what a drill press does, I will have a greater range of speed for my output shaft. If that is true, I can propel the boat really well (consider too that there is a variable pitch prop on the back making me faster as well) and with less energy going into the system (getting started will be easier, and maintaining speed will be far easier due to a better ratio and the advantage of a flywheel).
Consistent speed.
More to come, but roll that around for a bit and let me know what you think.
Carry on.
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