Another possible path for the Bessler wheel

[murilo]

Finder,
thanks for your words.
Pls, according this last photo, accept one more small suggestion, or correction.
The 'touch'' point between the two SHUT weights must be in 90deg line to device's axle and the tangent of these same OPEN weights must be in parallel to this main axle.
You are right about ''mass'', or dead-weight.
Best! M.
>>> Edition:
Pls, don't consider this msg.
You are doing some stuff different and clever of my design, what is get a local compensation for each of just 3 active external weight.
My note would be valid just if you use 4 pairs of full active weights, or hammers, with the compensation from opposite pairs.
Sorry! Best! M.

[path_finder]

The next step of the building: implementation of the mechanism in charge of the push/pull of the scissor summits.
The first diagram summarize the assembly. The shot then shows the corresponding building.
The three sides of the violet triangle are the axle of the three rotating pairs (A, B, C).
Each pair (p.e. A) will be connected to the opposite control bar (named A', and colored in relation with) by a linkage not shown yet in the shot.
Next step: attach the three linkages and connect the central bar (in green) to the outside world.

[path_finder]

We will return back later to the 'order three' design, where the control mechanism is a little bit more complex.
One of the rules described above is the linkage between two diametrally opposed pairs of weights.
This concept has obviously a consequence if implemented: the number of pairs of weights must be even wich is not the case of the flowerbowl in that state..
The corresponding design must contain SIX pairs of weights, like made in the wheel on the shot hereafter (where the linkage between the pairs of weights is not implemented yet).
Like suggested by some member in a post earlier, there is a possibility to obtain a keeling position at 12:00 and 6:00 instead to keep the two opposite pairs of weights in an horizontal plane (like indicated in the shot).
This is true if we do nothing, but there are severals solutions:
- The first one, like explained in the second drawing: the idea is to use two pins wich will lock in position the two branches of the scissor.
The questions now are: when these pins must be engaged, and then when they must be removed (allowing the expansion of the scissor at 3:00 and 9:00)?
- The second one consists in the take-on at 6:00 of the two weights, on an horizontal platform attached to the excentered COG position, if these weights are rolling on the plate (wich supposes a mechanical change versus the today's geometry).
- a third solution is to include some pins inside the rods connecting the pair of scissors.
In that case the presence/absence of the pins can be effective by the rotation of this connecting rod itself. This could be one of the clues shown in the MT138 'toys' drawing, in particular the A and B parts.

edited: the third solution

[Trevor Lyn Whatford]

Hi path_finder,

I do not think your latest drawing would have an advantage as the force required to remove and reinstate the pins would be to great, and that there is the alignment problems, I think a MT 26 & 27 variation would be better.

Well done though for exploring the transverse path of MT 24,25,26,27, as there is an advantage in the transverse path with some designs.

I am still learning how to edit videos and will post them when I have cracked it. My son posted my first two videos on you tube and I posted the last one, I had no idea that it takes over a hour to load them up, and it seems to load a frame at a time.

Yet again very good work, regards Trevor

Edit, it seem by your edit you have things under control, Path_finders edit was while I was writing this so he did not see this and I did not see that, happens alot on BW.com.

[path_finder]

Dear Trevor Lyn Whatford,
Many thanks for the advices.

The previous drawing was just for the principle (the cornered parts are not appropriate).
The next drawing gives some better details on how these mobile pins can be used for locking the scissor arms in the horizontal position (the position colored in grey).
Don't forget that this action can be done not only on the upper side of the scissor arms, but also on the lower side, the both locations giving a way to implement a flip-flop mechanism. I'm studying that point.
Just for the completion of the description, hereafter is a shot showing now the six tubular rods connecting the opposite pairs of weights.
After the first experimentation I have the impress to be on the good path, even if it's not perhaps the design built by Bessler.

[Trevor Lyn Whatford]

Hi path-finder,

as I said in my edit, you seem to have every thing in control, I will watch with interest, and thank you for sharing.

Regards Trevor

[DrWhat]

Bessler said "weights acted in pairs. ONE took an outer position, another an inner position" or something similar.

The question is when he said "ONE" did he mean one entire PAIR of weights or an individual weight?...

Nice work p_f.

[murilo]

There is no doubt, the unbalanced wheel is already here... a goal!
Score now is 1 x 1.
Now you need another goal, which is the command, or switch the PM- where I failed, up to now.
( the goal will ask for a self managed PM wheel, or something else, as OU. )
Best!
'some member'

[path_finder]

Curiously the requested solution for the motion of the connecting rods is the same than for this other design here:
http://www.besslerwheel.com/forum/download.php?id=8432
In this last design (including the reductor) the pairs of weights are acting in a vertical plane, versus the design above where the pairs of weights are acting in an orthogonal plane.
But the challenge is the motion of the arms with the correct dephasing.
IMHO all the mechanisms allowing an alternative motion of a point along a segment are based on the same principle. Remember here:
http://www.besslerwheel.com/forum/download.php?id=8065

If the two translations are equal in length, but orthogonal, we have a perfect reciprocator

Another useful idea has been exposed here:http://www.besslerwheel.com/forum/download.php?id=8189, where the demonstration is made we can replace a asymmetrical scissor by a pair of springs, allowing the linear shift for the middle of the rod.

[rlortie]

Bessler said "weights acted in pairs. ONE took an outer position, another an inner position" or something similar.

What he did not define is inner and outer: Rim to axis or face of wheel to center of wheel width?

Ralph

[path_finder]

Hereafter an animation showing the theoretical mechanism, needed for the requested motion of the sliding rods.
The ends of the orange rods are sliding on a diameter.
The size of this mechanism (basically the diameter of the red circle) depends from the requested expansion.
There are three subsets, giving six attachment points.
The guidance of the orange rotating rods can be made by the four parts of an astroid (not represented) acting as an envelop for the rods.

edited:
A mechanical device composed from a fixed bar with endings sliding on two perpendicular tracks is called a trammel of Archimedes.
The first to investigate the curve was Roemer (1674). Also Johann Bernoulli (1691) worked on the curve. Leibniz corresponded about the curve in 1715, and in 1748 d'Alembert did some work on the curve.
In addition to the basic trace obtained by an inner circle that has 1/4 the diameter of the fixed circle, the mathematician Daniel Bernoulli discovered in 1725 than an astroid is also traced by an inner circle that has 3/4 the diameter of the fixed circle. In other words, this traces out the same curve as the inner circle with only 1/4 of the diameter of the larger one.

[path_finder]

Must see this URL: http://userpages.monmouth.com/~chenrich ... lling.html
At the middle of the page is a Java applet.
Select D=4 N=3 (guiding cycloids) and D=3 N=1 (rolling trochoid).
Click on the black touch point between the circles and drag with the mouse.
You get the mechanism for the wheel above.

Then if you select now:
D=6 N=5 (guiding cycloid) and D=2 N=1 (rolling trochoid)
You get now the MT137 drawing

And finally a gift for John Collins:
select now:
D=5 N=4 (guiding cycloid) and D=4 N=1 (rolling trochoid)
You get now the wedding of the pentagram and the square, a old concept of our friend.

You can try some other couples of values.
You will find the justification of the shape of my cam here:http://www.besslerwheel.com/forum/viewt ... 5632#75632

For those members/guests using a browser not supporting the Java applets, the corresponding curves (unfortunately static) in the right order queue.

[sadiq attamish]

hi path _finder
a well done ,but your designed it does work,you are genius,but you are not lucky because god not planing to give you the secret.what i can do for you.my wish to do so,but this thing not from my levels.thanks

[path_finder]

Dear sadiq_attamish,
Many thanks for the encouragement.
I don't think God has anything to do in this scenario.
What you invoque as a secret is only a momentary lack of knowledge wich will be soon fullfilled, I hope.

[path_finder]

The previous shot shows the wheel with two opposite pairs of weights linked by two light but rigid rods.

A first mechanical problem is coming from the population of the rods in the central room of the wheel: the distance between the both rods of the same pair is variable (dependent from the aperture of the both scissors). Therefore there are some conflicts during the motion, and to solve this there are not a lot of solutions. We must abandon the idea to pass through the center.

BTW one of the solution is to have two disks (one for each pair of weights), where the summit of the scissor can be attached, like depicted in the drawing hereafter. The constant distance D between the both summits is respected.
Remember the motion of the weights here: http://www.besslerwheel.com/forum/download.php?id=8397
Obviously this supposes the two disks synchronization (same speed, same rotation way).

At this step you can imagine to link these two opposite disks by a chain or a belt: but it is not so simple, because you must also synchronize these two disks with the other pairs/disks of the wheel.
On a mechanical point of view one difficulty is coming from the fact that each disk must accept two linkages: one side of the disk will be reserved for the scissor summit, the second side for the rotation of the disk itself (it requires obviously an axle). So far the only solution for the synchronization linkage is a pulley located inside the plane of the disk (orthogonal to its axle). It is not inconceptable but the full assembly will be similar to a 19th century factory.

If we continue the analysis we will discover another problem: even if all the disks are correctly synchronized together, there is still remaining the question of the link with the main wheel rotation.
An elegant solution is coming from a direct linkage of each disk to the main wheel (without belt, chain, pulley, cardan, etc.).
This solution is known since a long time: the epicycloidal differential gearing, already in use in 2600 BC in China, in the 'Chariot pointing the south'. See here (again): http://www.stirlingsouth.com/richard/Chariot.htm

IMHO a epicycloidal differential gearing involving the main wheel and a grounded disk inside the wheel, could be a clever solution.