The summary of my latest studies

[Richard]

Dear Path_finder...

it is a most beautiful work we see unfolding here...you pose a question:

The question still remaining is: what mechanism will oblige the two carts to keep always the almost upper position?


a "dynamic" counter balance. I.e...a pendule?

[path_finder]

Next step of the building: the two primemovers.
Hereafter a shot of this kind of rhomboidal primemover.
The two crossbars with their four rollers each (to be inserted inside the grooves), are located at each side of the main frame (supporting the four weights)
If the concept seems to be confirmed as good, there are remaining some important mechanical problems to solve, in particular we need a way forcing the two crossbars to keep their mutual distance (instead the rollers are disengaged from the grooves).
I'm working about, trying to finish before my new travel next week (far from home for a full month, I will not be able anymore to pursue my building and my experiments)

[Richard]

Dear Path_finder

..enjoy your travel ..and well deserved rest from your efforts.

thought was

in particular we need a way forcing the two crossbars to keep their mutual distance (instead the rollers are disengaged from the grooves).


...perhaps...instead of the cross bars...you might condsider spring loading the wheels edit ( rollers) to keep a good contact through their rotation?

richard

[path_finder]

Dear Richard,
This is not specially an holidays travel, and will be a difficult exercise in Bamako(Mali).

For the builders,
One primemover ('rhomboidal frame' version) has been installed in the first compartment of the main wheel.
In the shot below the primemover is in the keeling position (COG at 6:00).
This is normal for the moment so long the major mechanical problem has not been solved.
As shown in the second shot you can observe the wrong position of the two crossbar planes, coming from the tendency of the eight rollers to be removed from the grooves. This fault was not observable with the dummy test primemover (see the shot above) where the distance was fixed by some rods. But now there is no way to implement such as interlink, some parts move in the interspace.

[path_finder]

For the builders:
I tried hard to solve rapidly the above mentioned problem before my departure.
After a deep brainstorming I found two interesting points:

First a big error: the primemover must be linked not to the wheel but to the crossbar, the both constituing the hamster in advance on the wheel (remember the cart before the horse).
On the previous shot you can observe I linked the primemover directly to the wheel. Wrong!...
This important change in the design obliged me to modify the crossbars supporting the rollers.
Two arms of each crossbar must be now more longer in view to allow the linkage with one of the primemover cross.

Then the mechanical modification allowed me to solve the question of the erratic clearance.
On the shot you can see two springs connected to the end of the new elongated arms of the crossbar: by the way, and like shown by the red arrows, these two springs are acting like a double lever, the two crossbars being pushed now outside with a more efficient contact of the rollers inside the grooves.

The hamster seems to be well alive.

[AB Hammer]

Greetings Path_Finder

Every step we take, and every move we make, we learn. But if we don't try we will never achieve.

Alan

[path_finder]

Many thanks to AB Hammer.

Being far from home, and therefore unable to pursue my buildings and experiments, I try to improve my theoretical knowledge.
I discovered an interesting Web site, explaining the 'three bars mechanisms' theory. Here:
http://www.mathcurve.com/courbes2d/troi ... arre.shtml
unfortunately in french, but Jim_Mich gave earlier an easy way to translate the text in the 'Tech support' section.

The Tesla reciprocating engine patent (Feb 6th 1894), where a piston and a spring enter into resonance together:
http://www.teslauniverse.com/nikola-tes ... ing-engine

[path_finder]

Dear all,
You may ask yourself why I was so much interested with the three bars linkages.
The reason is coming from my latest experiments where the concept has been confirmed as excellent, but the correspondent building not reliable enough.
Indeed my last attempt with the rollers sliding inside the grooves of the starwheel has no chance without a perfect (and expensive) CNC manufacturing.
This technology being not available at the time of Bessler, I decide to thing about a new way to implement practically this good concept (the revolving crossbar).
Thus I tried to find a way to let slide the end of the cross arm without any mechanical constraint at this point, and therefore eliminating the friction and alignment problems. At that level I remember my old practical experiments with the Watt linkage, which always seemed to me very efficient and reliable.
After several attempts I finally discovered the best values for the length and position of the three bars, needed for the obtention of the correct circular path of one cross terminator. The first animation hereafter shows the motion of one single linkage.

But if this linkage is alone the cross will try to fall.
This is the reason why in this first animation we need a fixed axle on the center of the cross (the axle in front side, and the wheel/linkage in the backside). You can observe the result wich is conform with the searched goal: a crossbar rotating at a speed twice the rotation speed of the main wheel.
But most important: with the central axis of the cross always located on the 3:00 clock radius.

Now what is much more interesting is the second animation below.
With a combination of four identical linkages like above, dephased of 45 grades, the cross is maintained in the free space, without the need of the previous axle, because the forces applied by the full frame prohibit now the fall
Thus we got a cross forced to rotate and always eccentered from the wheel main axis.
Install now an heavy weight at the center of the cross (the red ball) and you get a working wheel (I hope).

At least the practical building of such as assembly is not obvious, because the middle bars pass through the center of the wheel twice by turn.
After a deep examination I found (to be verified) a solution: the cross must be in fact a vilbrequin, like suggested in the third drawing.

Unfortunately I cannot verify now, and I will try to experiment this design when I will be back home.
Any counter-argument against the above description, is welcome.

[spacejam]

Greetings Path_Finder

Every step we take, and every move we make

I'll be watching you :)

[Ealadha]

Spacejam , i found a link for what you seem to be looking for :
http://www.google.ie/aclk?sa=l&ai=CxD_t ... te&cad=rja

:)

[AB Hammer]

Greetings Path_Finder

Every step we take, and every move we make

I'll be watching you :)

LOL Get in line. On one of my youtube videos I have over 400,000 hits.

[Grimer]

Greetings Path_Finder

Every step we take, and every move we make, we learn. But if we don't try we will never achieve.

Alan

Not only is this true on the experimental side of things. I've found it to be true on the theoretical side as well.

[daxwc]

AB Hammer

LOL Get in line. On one of my youtube videos I have over 400,000 hits.

Well, not exactly AB Hammer, that’s what happens after you mix a failed wheel build, a computer, a lonely night and a bottle of dark rum. I woke up with a sore finger and you got yourself a new fan 8P

[path_finder]

Here are some complementary personal comments on how the latest above suggested design can work.

In fact in this design the gravity is not the powering source of the primemover, but the centrifugal force.
When the cross is rotating the resultant action of the four centrifugal forces is to oblige the cross to keep its relative position on the 3:00 radius.
Then thanks to this particular position, now (at the second level) the gravity can complement the first action by creating a permanent torque.
But without the first step (rotation) nothing can be obtained from the gravity for a long time.
Starting from a rest position for the cross at 3:00, without any rotation of this cross, the wheel will keel at 6:00 after few oscillations.
This is the rotation of the four weights (in red, with a COG located at the center of the cross), which is the source of everything.
May be for this reason the cross should be attached to a very heavy flywheel.

If this explanation is confirmed, there are a lot of way for let rotate a secondary wheel inside the main wheel, with the mandatory to keep an outcentered position. This is typically the mechanical principle of the iris, see here:
http://www.youtube.com/watch?v=Lmpoinxfr70
http://www.youtube.com/watch?v=_V68j8ZMJ7s
And Bessler may have used some organ bellows to do that.

[ruggerodk]

Interesting link PF,
Has anyone made an attempt to build an IRIS that expands in the Z-direction?
That would be something like a telescope, I assume....but nor quite.

regards
ruggero ;-)