Sjack Abeling Gravity Wheel and the Worlds first Weight Power Plant

[Cherryman]

New simulation about the Abeling wheel from the
ab-az-cm-2.wm2d file.

I removed the motor and applied just a force onto the wheel for 400 frames to speed it up.

http://www.youtube.com/watch?v=rM8SmU9pjcI

But also this does not work.
Just elliptical pathes in a wheel do not work to get a gravity wheel working.

This animation has a force applied for the first 400 frames, to help speed it up.
After the 400 frames it must work by itsself and you see, how it slows down and then stops

I tried several of those designs, but it lacks the "extra" to give it additional force..

Same principal, little different look but that doesn't matter.

http://www.youtube.com/watch?v=nSaKQEn0Wwc&feature=channel_page

The one i did found most promising was this one:

Notice how the ball fly's UP the ramp due to its own speed. On that moment the ball goes up the ramp, it is faster and detaches itself from the spoke..   So the wheel is not bothered by the ball in the upmovement.. 

http://www.youtube.com/watch?v=GBygA2vOHx4&feature=channel

[mindsweeper]

Again the rigid joint problem.
I just fixed this using 2 pin joints.
Then it behaves normal.

Never use RIGID JOINTs in WM2D.

Stefan, that totally changed the way the forces work on the model. Canceling the desired effect of CF acting in the rear of the model. So it will not work that way, study the way the bar is attached and the forces that act. Placing the pin where you have just balances out the force.

EDIT: and if the rigid pin joint is a known bug I wonder why it has never been addressed by the software developers?

[mondrasek]

The more tweakable things the better, but wm2d lacks a single real world switch which normalizes all variables to real world settings including air, gravity and integrator settings...

Very true.  WM2D is just a tool.  For our purposes it must be used correctly.

The ability to lower Integration Error, Animation Step, Air Resistance, Friction, etc., is very useful when testing different configuration.  But in the end you need to keep your focus on the goal.  Do you want a simulation of something that will work when built in the real world, or just a neat trick? 

These are the reasons I have been trying to gently nudge the modelers to use the program correctly (as I know how) for the end purpose of an accurate sim of Abeling's device.  Suggestions like, model in the proper scale, and increase Integration Error, etc.

I work in robotics, where the motion is always an iterative process.  The controller calculates where each robot axis should be in the future after a given period of time (time step).  The controller then drives the motors with the appropriate current to try and get to the new position.  But before it gets there we are calculating the next point.  So we are never where we want to be and are always correcting our current positional error.  That is how the robot moves and is a very similar process to how the WM2D software must operate.  Our robots never follow exactly the perfect motion path that is programmed.  There is always a slight error, especially near fast sharp turns.  We can minimise this path deviation by shortening the time step (Integration Error, and for robots: which is limited by the controller CPU and amount of I/O you have in the system), or by slowing the robot down (Animation Step).

M.

[Cherryman]

Talking about strange behaviour...  Why is this going the wrong side???

[Omnibus]

@mondrasek,

How do you explain the rigid joint problem? Also, do you think parallel processing would improve matters and maybe somehow the object-oriented programming would be a palliative solution? Sorry to get into these software issues and detract from the discussion at hand but do you know what language was used to program this and any other details you've come across? Just curious.