Part Three is the Charm

[Fletcher]

Fletcher,
I think you are right about the storks bills, for several reasons. They can change the normal arc motion of a lever, to straight line motion and, multiply the distance moved many times. Also, they automatically reverse the direction of motion every half turn of the wheel. I.,E., in on the up side and out on the down side. Finally, they can easily be driven with a heavy disc.

Two or three stages,(of a storks bill), can increase the diameter of a wheel several times. Maybe this helps to explain why Bessler's wheel(s), were so thin yet so large in diameter------------------------Sam

All excellent and true observations Sam .. IMO there can be little doubt from the abundant MT comments that SB actions have a place in his working mechanical solution .. and sure do go a long way to why so much wheel diameter was required - space was at a premium it seems, and for more power generating ability perhaps, tho that could also be a factor of more room for more mechs ..

Finding the correct context for their use is the bit we are all after I'll wager ..

[Fletcher]

This time I start the sim and adjust the green pulley rope length down to 0.78 m length .. the yellow lw's are 1 kg each .. then I adjust the red hinge mass from 10 grams up to 1 kg to match the lw mass - then I adjust it again up to 2 kg each (2 : 1 ratio) .. you can see what happens !

At NO time does the top right sector falling yellow lw fall BEFORE the lower opposite sector lw MOVES towards 6 o'cl - i.e. the rope has no opportunity to advance the pull of the lower sector lw towards 6 o'cl .. it just can't happen because of geometry ..

> Therefore the pulleys (with rope connections) are completely useless (not required) in MT's 24 and 25 - they do nothing !

>> Yet they are there, for all to see and contemplate ..

>>> And as everyone knows by now the pull-rope for the spinning top is missing from the Toy's Page - there's a Harry in MT25 ..

Rant over ..

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[Tarsier79]

I think they would do more(but not enough) if the hinge points were more weighted.

[agor95]

Can members see minor alterations to this design that will improve it's operation?

Where is the torque being lost and not being used too rotate the frame?

[Tarsier79]

The place it usually is. Any time a weight falls it loses PE. That drop needs to be as efficient as possible at transferring energy into rotation. We are already dealing with a dead duck, the only thing you can do is make it more efficient to get closer to 100%....easier to do in sim.

[agor95]

So what would you suggest in stopping the mass dropping without supplying torque to the frame?

Maybe we can make a meal out of the dead duck?

[Sam Peppiatt]

Forget it----------------------------------------------------------------------------------Sam

[Tarsier79]

The duck has been run over for 8 hours of highway traffic. There is nothing left for even crows to eat.

Fletchers sim looks self explanatory to me. The fall on the RHS adds to rotation(but not enough), the fall on the left takes away.

As I said (and/or implied) before, we can improve the situation, but improving it doesn't actually get us closer to our goal.

[agor95]

Hum duck liver pate with freshly ground pepper on granary bread toast.

Why did the duck cross the road? Because it was a quacker way to go!

It has been said a simulation shows you what it was programmed to show you.
In a way that is true; However there two programmers the model builder and the software builder.

In light of the above we can see our goals are different one that waddels on the flat and the other flies.
One 2 dimensional and the other multi-dimensional.

The reason to study this question is not to achieve 'The Quest' but to educate those who wish to learn.
Shutting down and not making a meal of the duck takes away a good meal from more that us.

Duck a l’orange, n'est-ce pas

[agor95]

I trust readers looking at the simulation have watched the small Black/White Center of Mass marker?

Is it not below and to the left of the pivot point?

Can we improve on that?

Food for thought

[mryy]

If you look at the stork's bill (sb) of the Toys Page you will notice that it assumes a tapered form. That is, the links become progressively shorter from the handle end to tip. The MT collection shows sb's throughout either in tapered or uniform style. The fact that the Toys Page uses the former may carry significance.

Inspired by the non-uniformity of the tapered style, I modified the sb units in my design and shortened the outer links by about 20% to start. The angle formed between the shorter links is more obtuse than previous. At about the 10:00-ish region the short links create an optimal incline just before the spring impacts the lever. Consequently I now have the lever resting directly on the links -- actually the handles of the yellow weights rest on the links (the handles extend slightly beyond the width of the sb unit.) This does away with the pair of inner tabs used in the last version, further simplifying construction.

I really hope you love. I really do ...

[Sam Peppiatt]

What you have to remember, at least what I've learned, is; the weights can't be all the way down / out at 6:00. By 6:00 they should have returned to about half way in / up, to where the wheel is back to it's balanced state. And, if it's like most machinery, it should probably be a little before; before, bottom dead center, (BDC).

To say it with different words, maybe 10 degrees before, (BDC)-----------------------Sam

[Fletcher]

The duck has been run over for 8 hours of highway traffic. There is nothing left for even crows to eat.

Fletchers sim looks self explanatory to me. The fall on the RHS adds to rotation (but not enough), the fall on the left takes away.

As I said (and/or implied) before, we can improve the situation, but improving it doesn't actually get us closer to our goal.

Just for interest and completions sake - I include side-by-side sims of MT25 .. the LHS has pulleys and rope connections etc as before - the RHS has had the pulleys and ropes removed for comparison (as I have been saying) ..

In animation 1 the motor (forced rotation) is turned ON .. (in this post)

In animation 2 the motor is turned OFF .. (in the next post)

** Note that the sims are more realistically positioned for start conditions i.e. weight 1 has been given maximum GPE (about to fall), and wts 2,3, & 4 are positioned at their least achievable GPE's ..

My takeaways .. pulleys & rope connections don't serve any purpose in improving the OOB situation - therefore their inclusion is a 'heads up' for their use somewhere else that is both functional and important to B's. mechanical runner solution, imo ..

Also .. that no greater torque can be gained by manipulating the path a weight climbs or falls - iow's, all OOB wheels are only temporary OOB wheels .. the quest is to find the mechanical intervention that can turn that scenario and axiomatic truth on its head !!

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[Fletcher]

And for the real deal when the motor is turned OFF, and they start under gravity influence only, once given GPE !!

** Ropes or no ropes makes not a jot of difference .. note the usual back-torquing when a lw is in free-fall ..

**** Most of us can probably study MT25 and infer what would happen from experience, without having a sim predicting behaviour, tho for me its a nice to have ..

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[Tarsier79]

I imagine you have done one or two sims of MT24 in the past Fletcher.