Maxed out angular velocity

[tadietz]

In doing some flywheel-related simulations, I seem to have hit a limit on angular velocity. Even though things were proceeding smoothly and I would have likely been able to crank things up higher and retain stability in the system I built with Algodoo, I was unable to get a rotating object's angular velocity higher than +/- 157.080 rad/sec.

Granted, that is 9000 revolutions/sec or 540,000 RPM, which I am certain would be really hard to attain in any real world situation without complete vacuum and magnetic bearings, etc., but I just thought I'd put it out here and see if this is a known limitation.

[electronicboy]

It's a known Limitation of the default solver in use.
There is a way to make the object use the older solver which allowed much higher rotations.

Shamefully I'm currently unable to search for it, but I'm sure kilinich will pass by and post!

[emilk]

Increase the simulation frequency - if you are using the 2.1.0 beta, this can be done from Options

[Kilinich]

In doing some flywheel-related simulations, I seem to have hit a limit on angular velocity. Even though things were proceeding smoothly and I would have likely been able to crank things up higher and retain stability in the system I built with Algodoo, I was unable to get a rotating object's angular velocity higher than +/- 157.080 rad/sec.

Set hinge legacyMode=0 and allowDirectSolve=false shold do the trick. RPM will be unlimited.
Negative side is hinge became stratchable and less stable.

[tadietz]

Increase the simulation frequency - if you are using the 2.1.0 beta, this can be done from Options

That worked. Thanks.

I need to see if this is true of older versions, but the only issue I have now with 2.1.0 beta 8 is that I seem to have created perpetual motion, i.e., if I turn off the motor in my system, although it slows some, it speeds back up, and cycles back and forth forever (well, for as long as I can measure things) with no further power input.

[tadietz]

I don't seem to be able to create the 'perpetual motion' phenomenon with older versions and/or ones where the simulation frequency is left at the default value. Not sure what the implications are w.r.t. the 2.1.0 beta, but I'm pretty sure that, even though the increased simulation frequency is supposed to increase the simulation accuracy, something isn't going quite right...

I would love to think I have stumbled onto a machine design that is getting enough energy from gravity to somehow make what the sim is showing be true, but I still believe in the Laws of Thermodynamics, and am not buying into that interpretation just yet

[jon_joy_1999]

do you have interpenetrating objects in your motor? these will "add" energy to the system in many interesting ways when the solver attempts to de-penetrate them

[tadietz]

do you have interpenetrating objects in your motor? these will "add" energy to the system in many interesting ways when the solver attempts to de-penetrate them

Not sure what you mean by 'interpenetrating objects' but the simulation involves a flywheel that is a thin-walled cylinder whose horizontal axis is suspended on (i.e., collides with) another structure that the outer rim does not collide with.

Kind of hard to describe, but think of a gyroscope spinning rapidly in a horizontal orientation with its center axle resting on two supports. This is not so hard to 'draw' with Algodoo if one plays with intersecting shapes and makes use of collision layers to control what interacts with what in the overall machine.

[jon_joy_1999]

interpenetrating objects are objects that intersect and collide with each other. for example, box1 with collision layer A, and circle1 with collision layer B that intersects box1 would not be interpenetrating, while circle2 with collision layer AB would be interpenetrating box1 and circle1, while box1 and circle 1 would still not be intepenetrating.
if the objects are fixated or glued together this interpenetration is irrelevant, however if they are hinged together a force is applied to the object at the point of greatest interpenetration in attempt to separate the objects


can you upload the scene to algobox and post it here?