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I'm new to Algodoo.

I'm trying to demo a horizontal mass spring system for SHM, but no matter what I do, the system continues to lose energy. [Edit 2: Solved this too. It was air resistance. Toggled that off, and I'm good now. Thanks, I think ]

Here's the design.
1. Infinite vertical plane and horizontal plane
2. Box dropped onto the horizontal plane
3. Spring connecting box to vertical plane.

I've set spring damping to 0 and friction to 0 for the box and the horizontal plane. I've also set restitution to 1 for the box and the horizontal plane.

But, when I graph KE of the box, the graph over time shows a loss of energy. What do I need to change?

Also, can I graph the sum of the spring potential energy plus the KE of the box on a graph? If so, how? [Edit: Nevermind, figured out how to group the items. Still don't understand why I'm losing energy. Air resistance?]

Thanks.

I am facing the same problem with bouncing bodies.
Simple bodies bouncing in a square room don't loose energy but when adding bearings or hinges we see a loss of energy.
There is no air resistance, all materials are set to friction = 0 and restitution = 1

Is this due to limitations of calculation accuracy?

It has mostly to do with the fact that hinges don't "fixate" an object, instead acting like an elastic pivot, and that elasticity is not 100% energy conserving.