Acceleration (Follow up)

We have had a great deal of discussion on acceleration in the recent past. Defiinitely worth re visiting. Give some thought to this string of messages.

Walter Simberski promised us that he would lend his mathematical / physics expertise to further study the topic. He now responds. I placed his attachment with this message. G. :

Walter....

Thanks ! I'll share with the Group and step back to view their comments.

In # 4. .... When the rod tip is at the mid point of the casting arc it has to be significantly behind the mid point travel of the butt section of the rod because of rod bend. So at that point the casting arc may well be almost complete.

Still remains, I think, that for rod tip path to be in a straight line, we need to have application of force yielding rod bend which is matched to the casting arc.

Gordy

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From Bruce Richards :

Hi Gordy,

I read Walters paper with interest. The only thing I might be inclined to disagree with is his assumption that perfectly constant acceleration would not be desireable. He asserts that we intentionally don't accelerate constantly to avoid "kick back", and other problems. I don't think this is the case. I've tried very hard to accelerate in a perfectly constant way, but have not been able to do it. And I've never seen it in others either, but did see a 1.2, which is nearly perfect, and many casts under 2.0, which is very close to constant.

To think that big problems would occur if the acceleration was slightly more constant isn't entirely logical in my mind, nor has it been clearly explained why this would happen. Noel doesn't see how this would cause problems either. *

But this is all probably just a theoretical issue, I'm not sure that humans can achieve perfectly constant acceleration... If I ever get to that point I'll be very proud, even if it does cause problems in the cast and we're proven wrong!

Bruce

* Noel Perkins, Professor of Physics, University of Michigan.

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Bruce....

Seems we'd need some sort of casting robot programmed from the outset to yield perfect constant acceleration to help prove the point... though I suspect you and Noel are correct.

Gordy

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Gordy, we have the robot, but haven't used it in a while and have not tried programming constant accel. into it. Great idea though, we should try that!

Bruce

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