I have a working Bessler wheel in my simulation !

[scott_z]

Greetings users of Working Model simulation software.  I find the forum very interesting, but your conversations surrounding Working Model and the so-called "Chaos Pendulum" are very disheartening. It surprises me to see a couple true engineers involved in this conversation, yet the issue with the model has not been resolved.  It is not a software error.  It is a USER error.

I have reviewed the model called "BS7.wm2d". It looks like there were other slight derivations of this model but I will focus on the BS7 that contains the blue link. (By the way, the blue link was not necessary.  The way it was originally drawn in BS7.wm2d was acceptable).  I would like to comment on a some of the responses I have seen in these related postings, and I will quote the original sentences in the process.  After I am done I will gratefully reveal the ?imbalance? or ?acceleration? issue with the model. 

1.
Posted comment:  as related to the mass of the blue link.... "Whoever did this put an illegal value in the field that specifies the mass of the polygon"..."It would appear this field takes only integers"

response: wrong - Working Model will accept scientific notation (i.e. 1e-12)

2.
Posted comment:  "simulation uses an impossible material for the coupling of the two bodies"

Response:  wrong - In any motion simulation package you would know that this is a common practice used to utilize the geometry of a body (in this case a coupler link) but yet not have its mass contribute the solution. These tools are very powerful, but they still need some level of usage understanding.

3.
Posted comment:  "the whole thing seems to have been drawn using polygons...these are unreliable in this program when used in this way"

Response:  since when ?

4.
Posted comment:  "On the second (downloadable) model, the acceleration effect seems to be produced by the WEIGHT of the blue link bar. It set to (something) -03 default. Set it heavier, the effect goes away (completely by .01) make it lighter (-05) and the effect is more pronounced. I would bet it is a rounding error somewhere"

Response:  of course changing the mass of this bar will cause differences in the rotation imbalance...It's offset from the aggregate Center of Mass of the entire system (also center pivot point)

5.
Posted comment:  "Poly 6 has a mass of 1Kg and momentum of 1500 Kg/m? as opposed to the other spokes who have mass of 1Kg and momentum of 1552.083 Kg/m?. You can clearly see the location of ply six on the plane as (-140,70) where the others are around (67.5,140), (140,67.5) and (67.5,140) non absolute"

Response:  Yes, you are correct, and you are very close to the main issue... and you may read on to the very bottom here to see the solution... everyone else, please read on to #6 below.

6.
Posted comment:  "gravity is a spiral flux.. forget computer simulations..."

Response:  What ?

7.
Posted comment:  "this is yet another "glitch" in WM2D"

Response:  interesting... a software?s glitch or a User?s glitch ?

8.
Posted comment:  "Hopefully it will lead to better simulation software"

Response:  completely aside from this entire topic we are talking about, any simulation software can always be improved

9.
posted comment:  ".....Chaos Pendelum"

response:  ouch !


Ok, now the solution?.. Someone was very close when they observed the X,Y locations of the inner rectangles not being symmetric (see #5 above).  However, what was not checked were the X,Y locations of the 4 ?S?-shaped polygons on the outer bounds.  The Y values for two of them are not equal and opposite the other two (you can find this in the Properties window).  So, how might one test to find this to be the issue in the first place?  Well, after making the correction for the mass Moments for the inner polygons (#5 above), it still had the imbalance causing it to ?fall? (i.e. accelerate). Therefore, remove the center pivot, replace it with a velocity motor with a value of 0 and create a meter for the motor?s torque.  When this is done, you will see there is a torque of approx 3.3 N-m required to keep it at 0 velocity (this is the imbalance tendency  we are seeing).  Considering all mass values and all moment values are now symmetric in the model and there are no external forces acting, this would lead someone versed in BASIC physics to believe that the Center of Mass of the entire system does not coincide with the main center pivot.  Therefore, make the X,Y changes to the outer polygons and re-run.  The torque should be extremely small, if not 0.  To verify the original issue is ?visually? gone, remove the motor, re-add the pin joint and run.  It should not fall.

I will not argue the fact that Working Model does have some has some bugs. And if you find one, please post it on our forum at http://forums.design-simulation.com/  so that the software can be developed and improved to be more robust.  But clearly, this is not the case of a bug.  It is a User oversight on the simple tactics needed to debug motion simulation models.

I appreciate the work you are all doing and I am interested in continuing to learn of some of the work being done.  If you think you have an issue with the software and would like to discuss it, please email us at wm2d.support@design-simulation.com .  That is, of course, if you are using a LEGITIMATE copy of the software.

[broli]

So basiclly all you did was correct the position...in other words you you just "fixed" the perpetual behaviour away  . That would be truely funny.

"Wait people lets put a nail in there.See we now that evil perpetual motion is gone."

What I found truely remarkable is the chance of niente getting this setup to accelerate. I'm going to spend some time with this one.

[AquariuZ]

However, what was not checked were the X,Y locations of the 4 ?S?-shaped polygons on the outer bounds.  The Y values for two of them are not equal and opposite the other two (you can find this in the Properties window). 

Hmmm. I missed that...

Thank you very much Scott.

[hansvonlieven]

Greetings users of Working Model simulation software.  I find the forum very interesting, but your conversations surrounding Working Model and the so-called "Chaos Pendulum" are very disheartening. It surprises me to see a couple true engineers involved in this conversation, yet the issue with the model has not been resolved. It is not a software error.  It is a USER error.

I
Ok, now the solution?.. Someone was very close when they observed the X,Y locations of the inner rectangles not being symmetric (see #5 above).  However, what was not checked were the X,Y locations of the 4 ?S?-shaped polygons on the outer bounds.  The Y values for two of them are not equal and opposite the other two (you can find this in the Properties window).  So, how might one test to find this to be the issue in the first place?  Well, after making the correction for the mass Moments for the inner polygons (#5 above), it still had the imbalance causing it to ?fall? (i.e. accelerate). Therefore, remove the center pivot, replace it with a velocity motor with a value of 0 and create a meter for the motor?s torque.  When this is done, you will see there is a torque of approx 3.3 N-m required to keep it at 0 velocity (this is the imbalance tendency  we are seeing).  Considering all mass values and all moment values are now symmetric in the model and there are no external forces acting, this would lead someone versed in BASIC physics to believe that the Center of Mass of the entire system does not coincide with the main center pivot.  Therefore, make the X,Y changes to the outer polygons and re-run.  The torque should be extremely small, if not 0.  To verify the original issue is ?visually? gone, remove the motor, re-add the pin joint and run.  It should not fall.

G'day Scott.

I can get the idea that an imbalance in the system (it being asymmetrical) will introduce torque. So, one would expect the system to turn until it finds equilibrium and wobble a bit maybe and eventually come to a standstill. It should however not go into an uncontrolled accelerating spin.

Are you seriously suggesting that if I build a contraption with the same initial imbalances in the system it will start spinning out of control? I think not. Therefore it would appear that this particular initial set-up triggers some problem in the programme.

If the programme is a genuine simulation, it should be able to simulate the behaviour of the device as drawn in a realistic fashion.

Hans von Lieven

[AquariuZ]

Are you seriously suggesting that if I build a contraption with the same initial imbalances in the system it will start spinning out of control? I think not. Therefore it would appear that this particular initial set-up triggers some problem in the programme.

I think he refers to the fact that two outer polygons were incorrectly placed on the grid, something you cannot do real world, thus creating a torque in the program which would not exist real world.

It would be debatable if the program should allow this or not, as it is just that, a simulation. Maybe an idea to add a check model function if the end goal is a symmetrical model?

Very hard to call, but from his reply I understand why it fails. Too bad this "flaw" cannot be built for real.