We don't care the Bessler wheel, the most important is to build a working wheel...

[path_finder]

Dear ectropy: good strategy.


This new animation 'legs_ex2.gif' shows an alternate design, but respects the precedent rules:
- The ideal path cam has been replaced by an excentric circle
- the center of the circular cam is attached to the 'virtual fixed point' obtained by the 'cross' design
Here the single rod attachment of the weights has been replaced by a lozenge (rhomb) wich allow to reduce the outer attachment points number from eight to four, each lozenge supporting now two weights. Even if this seems to be typically an unidirectional design, it is in fact a big step to the bidirectional motion.
I'm pretty sure that the best of yours detected a possibility for a very important improvement...

[broli]

path_finder, you jump to new models too quickly imo. You spend little time asking yourself why you ditch a new model in favor of another.

[path_finder]

Dear Broli,
They are not some new models, they are different avatars based on the same principle. I apologize if there is too much materials put at your reflexion and for the guests, but sometimes it's necessary to describe all the steps for a good comprehension (Not all are an expert like you)
In any case, many thanks for your attention.

I furnish the answer to my previous post:
The most important improvement is coming from the use of the lozenges instead the single rods. Indeed doing that, we are applying an homothecy brought by the lozenge (rhomb).
We can now remove the circular cam and replace it by another circular cam, much more smaller, where we will attach the fourth (free) point of the lozenges.
The animation 'legsC_ex2.gif' hereafter shows the motion regarding this new cam.
This time the linking segments (in green) are crossing in a fixed point located between the main axis of the wheel and the center of the new circle.
It's obvious that the lenght of these segments is not constant (sometime they are diameters passing trough the center, sometime they are just cords).
Look with attention at the motion of this segments (remember an earlier post)

So the question is: how this can be made physically?

[ectropy]

Hi Pathfinder, I don`t seem to be getting my point across re; offset axis, whether it be fixed or "virtual". Mind you there is no such thing as a "virtual" axis. My conclusion does not stem from theory but from analysing way way back why my wheel failed to give me even a hint of motion. Only to realise that it was pretty obvious really. Any offset axis will tend to pull back or be pushed back towards the main axis when weights are applied to the "cam". Which demonstrates that the positive and negative torque is acting on the "cam" axis and not the wheel. OK, no more on an offset axis. Regards.

[ectropy]

Hi again Pathfinder, My "cam" was not a solid disc but a ring as the main shaft was supported by bearings on both ends. The main shaft protruded through the "cam". The "cam" was held in position by cam followers and rotated (well it was supposed to) at the same velocity ratio as the main shaft. Aah! I remember well, the disappointment. Regards.

[path_finder]

Dear ectropy,
Are you speaking about this ?:
http://www.geocities.com/RainForest/5832/perpet6.htm

[ectropy]

Hi Pathfinder, Nowhere close. Regards.

[path_finder]

This is the answer to my previous question ('how to setup physically this design'):
simplify (remember my signature).
Just concentrate the fixation points and make the fusion of the closest parts.
The result is the animation bellow.

Please note here:
1. The simplicity of this design.
2. The acceleration/decelaration of the weights (principe of Sjack Abelin) is applied here, without a 'gas power plant'
3. The presence of a cross

Now the point is: how to install this prime-mover and how to link it with the main wheel
(respecting the rules given by ectropy, co-incident axis)

[ectropy]

Hi Pathfinder, You certainly come up with some weird and wonderful ideas. Congrats to that. But that damn offset axis? Regards.

[path_finder]

(Sorry for the delay, but I came back home from the 'La Réunion' island, and I had to prepare my next trip to Ivoiry Coast).

The last animation 'rhombC.gif' proposed a suggestion for a prime-mover including the acceleration / deceleration phases.
If we cannot use an elliptical cam like as described above earlier
(see: http://www.besslerwheel.com/forum/downl ... ce7ae28a6b)
we need anyway a mechanism allowing this kind of path.

Also we saw earlier that a simple cord can be used, but this is not really reliable.
(see: http://www.besslerwheel.com/forum/downl ... ce7ae28a6b)

The next animation 'ellipse3.gif' shows how to oblige a point to follow an elliptical path by the mean of some mechanical links.
Instead to use a lozenge (rhomb) a parallelogram must be used because the lengh difference of the ellipse orthogonal arms.
This animation shows the principle, but the final design has some little bit different measurements.
This design needs TWO rotating rods, the blue one anticlockwise, and the red one clockwise, with the same rotation speed.
These both rods are completed by two other on the opposite side with the same lengh, thus making the parallelogram.
An additional mechanism, based on some gears are therefore required (not shown).
The most interesting of this design is inside the diagonal.. Do you see?

[path_finder]

The diagonal of the parallelogram can be very useful if
1. it's length is elongated
2. it is passing through the central axle
This feature is shown in the next animation 'ellipseB.gif' hereafter.
You can see a rod (black) linked to the external axle of the parallelogram, with a length greater than the sum of the both arms, and (most important) passing through an hole on the main axle.
The path used by the other side of this rod, is the green curve given on the next drawing 'ellipseB1.png'.
It's obvious that this particular mechanism can be used now:
- either for lift-up the weights between 4:00 and 6:00 (a very old leitmotiv now) per example with some cords
- either for supporting the weights
meanwhile by neutralizing the unused second half of the curve
Depending of the neeeds the mechanism can be rotated of 90 grades.
I'm waiting your comments (and perhaps some applications?)

[murilo]

Path, hi!
These are absolutely beautiful and elegant ideas and I hardly dare to imagine the clues you used for arrive to them.
In any possible future and practical conditions you have to be proud of them!
For the other side, and always in second to any ideas conceptions, come the computer modeling, the hard design and the prototype assembling questions.
Under this view, you have already problems for the rest of your life, since the ideas demands are just like physiologic ``orders``.
Congratulations!
Murilo

[path_finder]

Dear Murilo,
Many thanks for your encouragement. You are alone since a lap of time proving me that my literature still has an interest for the readers.
Regarding the models I can tell you that I made a practical realization each time the theory seemed to be able to be confirmed with an acceptable level of confidence.
Per example if you remember the drawing 'trolley2.png' earlier in this topic:
(can be seen here: http://www.besslerwheel.com/forum/downl ... 3355bb3f76)
the corresponding model is shown in the picture 'trolley4.jpg' below.
In that state (some parts are missing) it don't work. There is no shame to accept this fact (the torque is strong enough, the 'virtual fixed point' is needed)
All my wheels are made with polycarbonate flanges therefore transparent (instead who you know).
I regret do not see here in this forum so many pictures of practical attempts, even unsuccessful. There are a lot of good theoricians, but a small number of praticians...

[murilo]

Path, hi!
At least you know that I understand your case.

In an ideal pragmatical thinking, should be enough ONE good idea and one good model - btw, your model is quite well done and better than mine.

Other point is the practical mechanical vision for solutions of real and experimented professional over a project you have - this is also too hard to get.

As a sub-group of the theoricians, as you said, never to forget the blablablablers, that always arrive to nowhere, thanks to their non-imagination strong skills!

Cheers!
Muliro

[path_finder]

After review of the previous animation we can simplify (remember my signature) the design by this way (shown in the animation 'ellipseC.gif' bellow):
We need TWO disks (blue and yellow on the next animation) rotating on the same axis, at the same speed but with an opposite direction.
The mechanism to obtain this mutual counterwise rotation will be shown later.
For the moment we will use one axle on the rim of each disk, where two rods will be attached.
If r is the radius of the small disk (blue) and R is the radius of the big disk (yellow),
the red rod linked to the rim of the big disk will have a length equal to r,
and the blue rod linked to the small disk will have a length equal to R.
These two rods are linked together at a point where the third rod (black) is linked too.
The black rod passes through the main axel as explained earlier above (and like in the MT135).
So we have a practical unit able to obtain the same result like the theorical animation above.

Dear ectropy, this design could be able to reach your favorite rule (co-incident axis).