Speculations on the witness's evidence

[eccentrically1]

It could be a smooth lift the way the little Y shaped arms engage with the lifters.
Also, why did he change the way he lifted the stampers from the Meresburg wheel? Wouldn't it have been easier if the stampers were closer to the axle like they were on the Meresburg? Or does the Kassel have an easier lift?

[nicbordeaux]

For what it's worth, a square "pulley" acts as a cam. Variation of the force over time/distance thing. Amongst other things. Like the fact that once the "peak" is past, the load is held as in a compound bow.

[eccentrically1]

Good point Nic. That would make a difference wouldn't it?

I wonder if the wiki should have two power pages.

[nicbordeaux]

What on earth is a wiki power page, and why two ? You have me lost ...

[eccentrically1]

oh sorry The wiki is here:
http://www.besslerwheel.com/wiki/index. ... eel_Output

[ovyyus]

The simple lifting of a known weight by wrapping of a rope around a known diameter of Bessler's wheel axle tuning at a known RPM speed with speculation that it might have slowed down is a vastly more accurate calculation.

OK, let's run with that...

Attached is a crop of Bessler's Kassel wheel drawing showing a bucket hanging from the axle. It is described as a bucket for lifting water. Using Bessler's scale drawing for size, the bucket volume is about 10 Litres. It's a typical bucket size, even today.

If the wheel turned at 20 RPM while lifting a full bucket of water (plus a couple of kg's extra for the weight of the bucket and rope) then work done is about 25 Watts, or about the same as my water screw power estimate. Coincidence?

[rlortie]

Jim_Mich

Your concern about the square pulley;

The screw is shown as being driven by a twisted rope belt on square pulleys. I have no idea why the pulleys were square. Square pulleys make no sense to me.

You know and I know that a 'V' or flat belt calls for the pulleys to be in alignment, they must 'track'. Even a flat belt pulley usually has a slight crown in it keeping the belt centered. My 48" belt sander is no different.

Look at the picture one more time, Please note that the screw pump is far from being aligned with the wheel axle in any direction. Thus the square pulleys, and they do make sense!

The rubbing or friction you speak of can only happen when the rope initially falls into or leaves the groove four times per revolution. This is even less noticeable on the forked wheel pulley. A round pulley out of alignment would rub constantly.

Not only are the square pulleys a viable solution for UN-alignment they also relieve the friction on the guide bearings by eliminating a belt tension-er which to my thinking would have increased the friction three-fold.

Ralph

'The voices in my head may not be real, but they have some really good ideas.'

[daxwc]

So why are not all pulleys made square? It is much more effective to increase rope friction on the pulley by crossing the rope, but I can’t see any advantage to a square pulley. There is actually less surface area in the circumference of a square than a round pulley that was made the same diameter, making I would assume more prone to slippage. Ralph could very well be right that by adjusting the B holder he maximised surface contact on the square pulley, but look at the axle. What in the world stops the rope from slipping at the axle, it seems to have a very poor friction contact.

One wants as much friction as possible on the rope and as little friction as possible on the screw bearing and wheel axle bearings.

[eccentrically1]

Where is the quote about the rpm slowing to 20 when the water screw was engaged?

Is it possible that the water screw could only be shown from a dead start and that might explain why it never got to 26 rpm? If the wheel's inertia was partially responsible for weight lifting, as Jim has suggested, because they could flip the rope for the other demonstrations after the wheel got up to 26 rpm and then start the lift, maybe that technique wasn't possible with the water screw because of the funky pulleys on the screw and axle.

[Unbalanced]

http://www.besslerwheel.com/forum/viewt ... lley#84700

[rlortie]

There is more not less friction in a square pulley than a round one. Not to mention that a square pulley allows for UN-alignment of driver to driven or driven to driver.

A square pulley with crossed rope is making contact on all four corners. wrap a rope around a round object and pull it back and forth, note how much equal tension must be applied on both ends to prevent it from slipping.

Now try the same on a rectangle, size is of little importance and it can be smaller than the round version. You will find that less holding tension is required than on the round!

Unbalanced has joined the thread, being the nautical man that he is, I am sure that he is aware of the term 'Lay of the line or rope'. First, rope does not like sharp 90 degree bends, the friction of the rope slipping is ten-fold that of a round windlass. The flat or linear area of the square pulley is irrelevant and can be much shorter than the circumference of a round pulley.

I have seen many of deckhands get their ass chewed for mooring a line in a figure eight against the 'Lay' around a bollard cross bar.

I stand firm on my theory that Bessler used square pulleys mainly due to the UN-alignment of the wheel in relation to the screw pump.

Ralph

[path_finder]

IMHO the explanation of the square pulley is very simple:
If the rotation speed of the wheel is constant, and if you use some crimps forming a square frame (for a better transmission of the rope), you need on the other side a second square with the same size for the restitution of the primary constant speed (see the picture below).
For some reason they are not represented equal on the drawing.

[ovyyus]

Where is the quote about the rpm slowing to 20 when the water screw was engaged?

...It is a wheel which is twelve feet in diameter... making twenty-six turns in a minute, when the axle works unrestricted. Having tied a cord to the axle, to turn an archimedean screw for raising water, the wheel then made twenty turns a minute. This I noted several times by my watch, and I always found the same regularity... - letter from Joseph Fischer to J.T. Desaguliers, 1721

So why are not all pulleys made square? It is much more effective to increase rope friction on the pulley by crossing the rope, but I can’t see any advantage to a square pulley.

Daxwc, if Bessler was requested to drive the water screw from either wheel rotation direction (it was a bi-direction wheel and he did say it could drive a load equally in either direction) then it may be that the rope was not always crossed.

I think Ralph's explanation for use of the square pulley is the most likely. If my 25 Watt power estimate for the water screw is correct then the relatively low torque required to turn the screw would limit problems with rope slippage.

Path_finder, rotation of the wheel/screw would be smoothed out by inertia of the system. The two square pulleys are not represented equal because it is a reduction drive. A reduction drive is often used to match drive power with an applied load.

[rlortie]

So why are not all pulleys made square? It is much more effective to increase rope friction on the pulley by crossing the rope, but I can’t see any advantage to a square pulley.

Have you ever tried using a belt with pulleys or chain and sprocket on axles that are oblique to each other?

Crossed rope: is there an advantage to pumping water down the screw? If you reverse wheel direction, then to pump up you must change the belt configuration. The rope was not crossed for friction, but for direction.

Do you not see the lead-in and the lay-out advantage using a square pulley for an oblique angle.

I believe that some of the speculations discussed here are not unlike the Uncyclopedia biography of Paraprosdokian who was a legendary hero. He was not a citizen of any organized nation - he was Greek to all who knew him.

He was a great warrior, as handsome in life as he was centuries after his death. He had the strength, the stamina, and the wives of a hundred men. His legacy is stained only by facts.

Despite his legend, the true story of his days was not recorded by any reliable Greek historian. It was written by Herodotus. If modern day historians have correctly translated the accounts of his life, I would be very surprised.

Speculations of the blind witness's evidence is at some points no more credible than Bessler's.

As a school youth he was very skilled with the girls, though his teachers did encourage him to participate in boys' athletics instead, but on the other hand, he had different fingers. The face of this young child could say it all, especially the mouth part of that face. Eventually, he grew tired of following his dreams, so he decided to ask where they were going, and catch up with them later. As a young lad, he fought and killed an elephant using nothing but an oak branch. But this deed remains dubious - an elephant using an oak branch is no match for a warrior using sword and shield.

Should I go on? :-)

Ralph

[axel]

Can I just reiterate a point I wanted to make which seems to have got lost in my post.

If Bessler was able to make his first three wheels turn at 50 RPM regardless of whether they were one or two-way wheels, why would he make his final and most robustly built one, only able to turn at about half the speed of the others?

My suggestion was that it was so he could be sure that it would suffer less wear and tear during the long duration test because it would only have to to turn half the number of times, compared to say the Merseberg wheel.

We know he claimed to be able to make wheels that could turn slowly or faster, so this was deliberate. It seems to me that a slower turning wheel might produce less power than a faster turning one? If so that would explain the extra depth to his wheel when compared to the Merseberg one which was the same diameter but only a foot thick - he needed to add some extra weights.

Given that possibility I meant to suggest that perhaps it would be possible to produce a much faster turning wheel complete with extra weights that could generate the kind of power we seek for our modern electrical requirements.

JC

I think that in the faster turning wheels, whatever was driving them was closer to the center, and in the Kassel wheel the drivers were more towards the perimeter. Out toward the perimeter would make it have more torque on the axle right? More leverage.