The secret behind Bessler's wheel...

[AB Hammer]

raj

Thumbs up on this approach. It looks like some cool actions even if it don't work. But it defiantly needs built for test.

[Fcdriver]

The secret is changing the cost of lift, or the harmonic motion from 9:00 to 12:00! More like 9:00 to 2:00!

[sleepy]

Fcdriver,
I have seen you use the phrase "harmonic motion" several times,but I really don't know what it means. Could you try to explain it so I can follow your ideas with more understanding? Thanks for your help.

[Fcdriver]

Harmonic motion is the movement relative to the wheel. Understanding what effect the weight has on the wheel, in the different locations, is important. From 12 to 3 it accelerates the wheel, from 3 to 6, it adds bearing load, from 6 to 9 it releases bearing load, from 9 to 12 it slows the wheel.

[raj]

I am working on Ed's and Fcdriver's suggestions of relooking into the linkage system on this concept.

I am pleased that I have found a minor change in linkage that seems to be very interesting.

In short, it's about using long and short arms.

Raj

[raj]

I MAY have found something interesting but I am not sure of.
Before I could bring it on this forum, I would be grateful if you could kindly answer me the following question:

1. We have a fully balanced seesaw on its fulcrum.
2. We put two identical weights resting on the seesaw, one weight nearer to the fulcrum and one weight further from the fulcrum.

Question:
Can the weight NEARER to the fulcrum raise the weight further from the fulcrum?

Raj

[daanopperman]

Hi raj ,

1 ) Only if the fulcrum moves down with a velocity in excess of 10m/sec .

2 ) Only if the weight nearer the fulcrum have kinetic energy .

[rlortie]

raj,

Not unlike levers, there are three (3) different types of seesaw (teeter-totters) each exhibiting a little difference in the way they balance.

Lets use a plank that is 3" (7.62cm) thick and of any width.

Type 1. The plank sits on top of the fulcrum, this puts the COM slightly on the down side of our plank.

Type 2. The pivot or fulcrum is centered in the thickness of the plank via a pin or rod. Thus this style always keeps the COM centered.

type 3. The plank is center strapped to the bottom of the fulcrum, dropping the COM and placing it on the up-side of the plank. This is what Bessler depicts in his drawings. The pivot point is above the cross-bar.

This use to be referred to as the "Celtic Cross"... Note how the dampener weights are more massive than the pendulum bob. It is as though the bob and rod length are for timing purpose only, the dampener weights take advantage of the off-set COM, building kinetic and inertial properties.

That's the way I see it, for right or wrong, open for discussion!

Ralph

[raj]

@Ralph,

In my question above, my seesaw is as in your example type 2, moving after release from rest position, in a special arrangement.

I am calling my wheel on its axle as a horizontal seesaw on its fulcrum at rest and two identical pendulums with their identical bobs on the seesaw, the further bob to the fulcrum,moving up and the nearer bob moving down by same heights, after release from rest.

Raj

[Andyb]

Ralph,it sounds as though you are using this pendulum as a switch is this the case or am i mistaken, all the best Andy

[rlortie]

Andyb

No, I do not foresee the pendulum as a switch, but rather as a governor controlling speed. Pendulums with their physical properties were used to measure gravity at different points on Our planet. Their swing time aka "period" is mainly controlled by the length of the rod.

Bessler shows the rod to be of extraordinary length, the bob is much smaller than the more massive dampener weights. The depictions show the pendulum and cross beam being connected to a crank. Note the shape of said crank, it appears to be of shape and material that could easily be bent, seeking or adjusting for a finite radius to keep the wheel at a specific RPM.

This in turn keeps the wheel from over speeding, Cf and Cp are kept within their most proficient range of motion.

This is just my thoughts, I do not claim any scientific background and could be all wet! It is meant just something to think about. Remember, no one reported seeing pendulums on Bessler's demo's, but then nobody said there was not any?

Ralph

[ChrisHarper]

As Ralph hypothesises , I too believe that the pendulum(s) illustrated are not critical to create rotation per sê. Rather to keep the wheel turning within a very narrow operating band.

Logic then dictates this is to prevent rotational forces from impeding weight migration and / or overspeeding.

Noting also the bob size, some fine adjustment was required (tuning in ).

So whatever the arrangement Bessler discovered , it was neither brutal or impactful!?

What else would you expect from a watch maker.
Chris

[ME]

To add.

There were just a handful of mechanisms inside the wheel: eight or something.
At full RPM the mechanisms operate near the maximum Centrifugal Speed: Let's say the speed where at 12-o'clock the CF equals gravity - like that rock on a string making a perfect vertical circle.
Whatever mechanical system occupies that wheel, it can not affect the rotational speed. Only friction (or a load) will.
When the RPM drops the mechanism 'feels' gravity again which will likely not happen at the most convenient position inside that wheel. But the mechanism does and shall reset to its designed orientation (just assume it simply works). Now, under the influence of gravity, it's able to do whatever it is designed to do for adding torque and increasing the RPM again. With all kinds of sound effects and shaking (a couple of times per rotation) it will surely lower the wheel's life-expectancy.
A pendulum is almost a necessity for a smoother ride.

For small angles the period of a pendulum is about T=2π √(L/g), note: frequency f=1/T
Actually this simplification is simplified a bit too much: we miss a Moment of Inertia (MoI) - known to be a factor for resisting change of motion.
The pendulum-weight is (just) like a torque on a weightless stick, but could have been a weightless wheel too: τ = r x F = I · α ...
Anyway it is better to say: for small angles the period of a pendulum is about T=2π √(I/mgh)
To verify for a weight on a stick: I=mr², h=r --> mr² / mgr = r/g :: so that checks with the more known formula.

What does it mean:
Adding weights above a pendulum's fulcrum adds to the MoI, but lowers the frequency. Compare this with an equal weight it the Center of Mass with the same MoI, it will have a higher frequency.
In other words, now you can have a more compact pendulum rod with the some same low frequency as with a weight on a long stick.

[raj]

Very interesting debate.
That's what we expect from this forum.

Raj

[rlortie]

two interesting links helping one understand the simple use of pendulums for time keeping and low-friction mechanism for converting pendulum motion into rotational motion.

https://en.wikipedia.org/wiki/Corpus_Clock

https://en.wikipedia.org/wiki/Grasshopper_escapement

Ralph