Move an object until a constant value is reached?

Dear grasshopper wizards,

For a project on my university I want to make a moveable structure, consisting of rings with different radii (R1, R2) and bars wit a constant length inbetween.

For your sake a created a simplified little (the big one is way to chaotic...) algorithm to illustrate my problem. The desired movement can be desribed like this:

- One ring is twisted with a relative angle (degrees)

- This causes the ring to drop with a certain height (in Z, which is the unknown)

The big question is how to get the z-movement? I thought of two ways to solve this.

1) Mathematical: the path of a point on the circle can be described by an elliptical trajectory: a solution is found for two radii, but a uniform relation between z-movement, R1, R2 and a given constant bar length proves to be really difficult.

2) Is there a way to create a condition in grasshopper with a given twist and constant length > "Continue movement in z-direction, untill the distance between points reaches the given constant"

To illustrate i added some pictures.

Thank you all in advance,

Merijn Boon.

Attachments:

1.jpg, 70 KB
2.jpg, 73 KB
1gh.jpg, 164 KB

Replies to This Discussion

Permalink Reply by Chris Tietjen on April 23, 2013 at 9:46am

This might be helpful. It works within a certain domain of components and it's obvious when you've gone beyond that domain. Use the slider marked 'Rotation Parameter' first to see that it does work. Then you can play with the other aspects. The link length remains constant to the nearest thousandth.

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