I’ve made some progress with my ongoing problem of a folding mechanism and have abandoned all previous approaches.
Now, based on a model, I’ve found a feasible solution that I just need to draw and animate in Rhino.
I’ve gotten as far with the animation as the blue part also moves the two gray parts, but then at the end of the chain, the round bolt should only be able to follow the single curve. In the paper model, it would be pulled along the curve.
I watched the Bongo tutorial with the robot arm, but I can’t get the point object 13605 to be bound to the curve the way I’d like.
I don’t think I’ll reach my goal with this version of my design either.
As far as I can tell, Bongo can only work with properly defined axes, points, and curves, and then use those to create the animations.
Since my final result, regardless of the approach or connection technique I use, is always undefined at the last point, Bongo obviously can’t know what I want it to do.
The problem remains simply the last point of the mechanics, and you can’t find that point by constructing in Rhino without animation, and animation can’t run without a prior construction.
I’ve come to the conclusion that Rhino and Bongo simply aren’t the right tools to fully construct and test my idea.
I’ll probably have to spend some money to have my model drawn by a professional service provider.
Once this moving part is designed and the geometry works, I can try to import it back into Rhino to construct the sometimes mundane stuff that builds upon it.
There are really very, very few things that I can’t solve myself, and I never give up, but I truly believe now that the problem, however banal it may seem at first glance, cannot be solved with the capabilities of Rhino and Bongo.
You are right, Bongo isn’t designed to generate highly complex mathematical concepts on its own. You’d probably need AI for that . I myself do not have the necessary mathematical knowledge to solve your riddle.
But I do can make Object 13605 follow the curve in your V1.3.2 project. V1.3.2 001.3dm (784.7 KB)
Just make it child of Object 13528 and IK-constrained to the curve. That’s it.
Remember what I wrote about accuracy and precision? In your model, the pivot of Object 13528 isn’t exactly along the curve (which should serve as the axis).
I’ve now got the result just like you showed. However, the problem remains that the two gray areas are folding outwards.
Following your advice, I slightly bent the pieces in the desired direction before linking and moving them, but even then they still bend outwards in a completely illogical way.
Is it possible to set an external blocker? Something that Bongo would accept as a physical limit?
Theoretically, the long gray area is physically unable to fold outwards because it’s attached BEHIND the blue area, but the animation completely ignores this “limit.”
I always have a bit of trouble with English terms because my English isn’t very good, but perhaps there’s a trick somewhere to more easily adjust the 50/50 probability of the movement directions.
The gray parts should fall inwards, and according to the cardboard model, the round bolt at the bottom should then be pulled inwards along the circular path.
In the finished assembly, there must be an aluminum guide there to guide the bolt and fix it in place at the top and bottom.
Unfortunately, the system is rather puzzling and moreover bugged for rotations in ObjectSpace. It cannot serve to fulfill your wish.
As an alternative, I thought of an ‘in between driver’. An IK chain can be initiated not only through its head. The action can also be induced by an object in the second (or subsequent) position by means of keyframes. It’s a advanced technique that I didn’t mention this in the video “Whys of IK in Bongo 2.0”.
A demo model to show what I mean In between drivers.3dm (62.6 KB). I assume you can figure out what’s going on. The head of the chain is made a hinge - hence allowing free rotation. The “driver” has IK properties set to ‘none’ - hence it can be manipulated with keyframes.
Applying the technique in your machinery, the IK solver comes up with a very remarkable solution.
Despite my limited mathematical knowledge, my gut told me that 45°/45° wasn’t the right ratio for dividing the green parts, because the blue part doesn’t have a 90° angle.
Some reflection and experiment led me to this.
The green part should be half the size of the blue part.
. I myself do not have the necessary mathematical knowledge to solve your riddle.
