Algodoo

Nice mechanical and artistic work. I appreciate your attention to detail.

Thanks for the suggestion. I agree with everything you said, but I'm not going to add rollers or extra hinges for the following reasons.

1. The chain circles are friction-less, so they function exactly the same as rollers.
2. Adding rollers would not change the outside appearance of the chain.
3. Adding rollers would increase the body count and slow down the simulation.

See response.

Q: Is there any way you could explain to me how I could add it to yours?
A: Make a few links at 0.5 pitch and then keep cloning until you get a long chain.

Q: Because your chain has what appears to be a lot of jitter.
A: The sample chain in this scene is 20 meters long. The chain and sprockets should probably be scaled down before using. I didn't notice any jitters, but if you see some then increasing sim.frequency might help.

It's OK Xray. He used my Sprocket and Chain Generator, as I had suggested in his previous scene.

Well, if you don't understand it, then most other users won't either. This scene may be of interest to engineering students.

I got your PM. Thanks.

I couldn't have said it better, so I put it in the description.

In order to model a cantilever beam using one hinge, the bendConstant should be equal to 3*E*I/L where E = Modulus of Elasticity, I = Moment of Inertia, and L = Length of the beam. In other words, the bendConstant should be inversely proportional to the length of the beam.

Kilinich,

Thanks for the links. I should have searched for leaf springs before making this scene. And you are probably right about the lag.

I liked your older design, but this one is better.

Good.

Thanks guys.

Nice work. I like the "localized gravity" added to some blocks.

Using Kilinich's scene.my.xFor function eliminates the dependency on the Algodoo "for" function and also gets past the 64 count limit.

To display a slider for the thruster-group, select multiple thrusters (left-click first, CTRL left-click the second) and then right click on one of them. Pull the menu to the side if you want it to stay open.

OK. this is awesome. I like the consistent quality and style of your scenes.

Yes, I was straining to come up with new ideas without getting my panties twisted or getting too bent out of shape.I realize this scene is kind of a stretch for people to relate to. Maybe it will help some engineering student. Thanks for the comment and rating.

Well, I'll have to admit that it took me a while to figure this one out. Nice work. It made me think.

Also, thanks for commenting and rating my scene yesterday. I ended up deleting it because I found an error I couldn't fix.

My theory is that this scene is powered by Algodoo's inaccuracies from running at 30 Hz. This is based on the following observations:

1. If I run the scene "as is" then the scene's total energy increases.
2. If I run the scene at 1200 Hz then the scene's total energy decreases.
3. If I freeze all velocities and run the scene at 1200 Hz then all particles collapse to the center and the scene's total energy decreases.
4. If I freeze all velocities and run the scene at 30 Hz then the particles go all over the place and the scene's total energy increases.

Q: How can inaccuracies generate power?
A: They can't, but if the errors add up to a net increase in power, then I can use my poetic license to say they do. Algodoo errors propel this Gravity climber up the hill.

Q: How do you determine the "scene's total energy"?
A: Ctrl-A selects all objects. Right-click on one of the objects and select "information" on the menu. Undock the "information" widget and watch the "total energy" as the scene progresses.

Nicely done. I like how everything folds back into place.

Increasing simulation speed to 100 Hz will improve performance.

1. Find the equation for air density as a function of altitude from the equations found here.
2. Divide the equation by (air density at sea level) to get the equation for airFrictionMultiplier as a function of altitude.
3. Set scene.my.earthPos = earth's position.
4. Set airFrictionMultiplier for the object of interest to be equal to (math.vec.dist(pos,scene.my.earthPos) - earthRadius)*(function determined from step 2).

http://en.wikipedia.org/wiki/Density_of_air#Altitude

If earth positioned at origin then
scene.my.earthPos = [0,0];

in postStep code of object of interest:
h := (math.vec.dist(pos,scene.my.earthPos) - 6.371E6);
h > 20.0E3 ? {airFrictionMultiplier = 0.0}:{};
h < 0.0 ? {airFrictionMultiplier = 1.0}:{};
(h > 0.0) && (h < 20.0E3) ? {airFrictionMultiplier = -4.333E-14*h^3+3.311E-9*h^2-0.9498E-4*h+0.999}:{};­

translation:
The altitude of the object equals the distance between the [center of the object and the center of the earth] minus earth's radius.
If the object is above the troposphere then there is no friction.
If the object is lower than the earth's surface then set airFrictionMultiplier=1.0.
If the object is in the troposphere then set the airFrictionMultiplier equal to the [equation for air density as a function of altitude]/[density at zero altitude].

Note: The troposphere is only about 0.3% of the earth's radius.

A shining light in the wilderness of marble races.

Good work. Your scenes keep on getting better.

Good idea. Nice work.

Nicely done. Good design and explanation.

Thanks XRay. I usually strive for minimalist designs, but hadn't thought of that. It would be hard to get something simpler than a rope and pulley for transferring a tensile force in another direction accurately and with unlimited travel.