So this week's random simulation came to me during a dream. Well, the dream was still much cooler but basically it involved exploring a booby trapped dungeon or tomb. Out of nowhere comes the iconic swinging blades.

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This is just a simple dynamic bone constraint attached to an axe model.

First start out with the Axe model and only assign a signle bone.

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Place the Axe Pendulum in the choreography and rotate it so that it is parallel to the ground.

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Now, select the Sekeltal Mode icon from the tool bar. Click on the axe model and select the bone. Right click and add new Dynamic Constraint.

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In the Project workspace under the choreography, edit the Dynamic constraint settings.
Change the Stiffness setting under Target to 0%
Change the Drag property to 0%

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We are almost done at this point. What we have to do now is give the choreography plenty of time to run the simulation. I set my for 6 seconds.

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Change back to the Choreography mode by clicking on the Megaphone Icon in the toolbar.
Back in the Choreography window, right-click an open area and select "Simulate Spring Systems.
There it is!

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For multiple Axes, what I have done is to offset the Dynamic constraint for the different axes by a few frames. Set the first frame to 0% Enforcement of the constraint. After a few frames change it to 100%. Make sure that you have a strictly ON/OFF animation Curve in the time line. Just experiment with this and enjoy!

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He he I can play with this for hours ,thank's

Outstanding Mark.

Its rather odd... I was thinking just yesterday on how best to put together a tutorial demonstrating a pendulum swing. Nothing to do with a dream mind you but to demonstrate the basics of animation. I would probably have stuck to the manual method but thought expressions might be an option. I didn't even think to use dynamic simulation.

Your example here not only answers the basic need but presses it to the next level. Now I can just link to this tutorial!

Thanks!
Keep on dreaming.

An expression may be the best solution if you want the pendulums to swing contiuously. Even with Drag set to 0. There is still something that slows the pendulums down. I tried performing teh simulations with forces set to off as well (assuming chor forces also had air drag) but it didn't change the result.