Re-Inventing Bessler’s wheel Part Two

 I’m going to try to provide a better explanation for my design.  This will be in two parts because there are two aspects to this explanation.

To answer questions from my previous blog, the scissors mechanisms are mild steel, but the curved  guide arms are/were aluminium.  The weights are mild steel and there are two per lever, each pair weighs 80 gram grams about 2.8 ounces.  Not much but it seems to be enough on 36 inch diameter wheel.

To begin with I’ll concentrate on the so-call “work-around”, (WA) without which my wheel design won’t work.

Some of the text which follows contains assumptions about Bessler’s thinking.  The ideas described are how I imagine Bessler’s thoughts proceeded.

The main focus of action occurs around the six o’clock radius, when a mechanism approaches it from the right.  I use the word “approach”, because as we know, the wheel is permanently out of balance.  The weighted lever in the approaching mechanism is almost vertical but leans back to the right, or to the rear, by 18 degrees.  This encourages it to fall back a full 90 degrees immediately it’s pivot reaches the six o’clock radius.

At this point I believe it’s worth reminding everyone that every angle inside a pentagram is a multiple of 18 degrees, so the angles include - 18, 36, 54, 72, 90 and 108.  But there is one 30 degree added which doesn’t normally appear in the pentagon.

So the weighted lever falls to 108 degrees from the vertical radius, 18 + 90 degrees = 108. This provided a very small mechanical advantage (MA).  It wasn’t enough to do more than rotate the wheel a few degrees.  

It occurred to Bessler that making the weighted lever fall back to a point closer to the following radius and its weighted lever, would generate a considerably larger MA.  If he could design a system that achieved the extra MA, then the wheel would rotate further than the few degrees from before.  Incorporating this feature to generate the extra forward rotation would cause the previously fallen weight to counter-rotate, making its weighted lever ride further backwards towards its pre-fall position.  From this position the weighted lever would require less lifting effort to return it to its original pre-fall position.

Bessler noted that in the action of a  falling lever there were very few comments about the potential energy generated by a falling weight.  He thought that the loud noise made as it landed disguised the possibility that he might be able to tap the small extra source of energy before it landed, which it usually spent creating noise and miniscule heat.

He designed a scissor mechanism which would control the descent of the weighted lever, sending it in an elongated arch straight towards the following radius which had its own weighted lever ready to fall.  

The scissor mechanism could expand or contract and was operated by a weighted lever.  Bessler warned us to put the horse before the cart, so the weight used it’s falling mass to begin operating the scissor mechanism, reacting to its lever’s position and driving the mechanism.

The path of each mechanism was controlled by one long lever which was fixed to a pivot close to the wheel’s centre of rotation. The other end was connected to the mechanism but was lengthened to pass through it almost to the edge of the wheel.

Bessler used the scissor mechanism because he had observed that it was the most suitable method given it worked best when moving horizontally.  A slight slope would send it extending, whereas a slope in the opposite direction would send it contracting.  

The long control lever extended through the scissor mechanism to provide an anchor at its outer end to tie the end of a cord.  The outer end of the long lever was thrust backwards quite strongly by the fall of its weighted lever, providing a good pull on the attached cord. The cord passed over two pulleys.  One pulley was positioned close to the edge of the wheel and  directed the cord up and around a second pulley close the axle.  This redirected it down to the weight on the weighted lever in the previous mechanism.  

NB.  This last sentence is not necessarily correct.  The images I’ve interpreted suggest it might not connect with the previous fallen mechanism because it would be counter-rotating anyway.  Alternate suggestion requires the lifting of a weight around two or three o’clock, i.e, just past TDC.

Continuing…

As the first mechanism at six o’clock fell, it’s cord pulled the weighted lever in the previous mechanism back up just 30 degrees, into a neutral position aligned with the inner circle upon which all the lever pivots are stationed.  This small lift is designed to be work as quickly as possible.

This fast lift is necessary because once the the weighted lever moves past its own radius, it begins to travel uphill, causing a braking action on the turning of the wheel.  It can be likened to the action of a pendulum which falls until it reached bottom dead centre, and then begins to climb, unless the pendulum is shortened somewhat, when it speeds up.

The potential energy formed during the weights fall is used by the scissor mechanisms to drive them sideway towards the rear and the oncoming mechanism.

In the above image the pairs of red lines show the start and stop positions of a single weighted lever, according to Bessler’s original design.  The blue lines on either side of the sic o’clock radius, show the theoretical start and stop positions of each weighted lever when fitted with the scissor mechanism attaching it to the pivot point.

Comparing the two stop positions it’s clear that the blue lever has the better potential for lifting the fallen weight.

In the picture below I’ve removed the metal strips I added to reduce the lateral sway evident in my own model as they are not necessary in a well-built model! 

Hope this helps. More details in next post.

JC