Simple Devices & Experiments In WM2D

[Gregory]

I can't post an animation, because Wm2d crash when I try to make one.
But here is some pictures show the process step by step.
Hope I helped.

Greg

[inroades]

   Hello Greg,
  What a great job you did, thank you very much. I ran the clips in a slide show and that produced pretty good animation. I downloaded a sample version of the program and played with dropping a ball at different rpm and you are correct that rpm, ramp angles, weight release timing will be hard to manage. I had a thought to include on the top side a magnet to help overcome some of the lower ramp friction, just as the weight is released from the inside position it could slide past an opposing magnet to gain a little push in addition to the power ramp. 
     Please feel free to add any advice/counsel to the project as it is much needed and welcome.
     Thanks again
     Dale

[Tinhead]

I can't test it at higher Rpms because the WM2D has problems with collision at higher rpms, usually simply ignores the collision. I can be very angry in these situations.
But weight return with greater force at higher rpms, sure.

You have to change the simulation settings. Go to menu "World" -> "Accuracy". There turn off the automatic option for animation step and integration error and use your own settings. Normally I run my sims with an animation step of 0.01 seconds, if crucial even less. THe integration error depends on the average size of your parts. My test wheels are on avarage 1 meter in diameter, there I use a value of 0.1mm to run it. Calculation will be slow, but the result will be better.

Cheers,
Rainer

EDIT
Me again, Hi Greg & Gregory 

just a question in regard to the simulation pictures you posted. Is the collision turned on between the green ramp and the green weight?
If so your settings might be too rough, on the pictures I can see how the weight overlaps the 'cage' that surrounds it and how it moves into the ramp before it gets swung up.

If that is the case you can't trust the simulation results at all. The interference seen will result in a much larger repelling force than you could expect in real life. Even so it is a simulation, the participating objects should not overlap. If they do, as mentioned above, you have to change the settings.

Cheers,
Rainer

[Gregory]

Hi Tinhead,

Thanks for the advice, it was helpful.
Me stupid... Now I see how can I set the options to get a correct result for the collision, and everything.
Unfortunately, I don't like to wait much for such a simulation, but now I learnd sometimes patience is crucial... Maybe for my best designs... 

Yes, only the green weight allowed to collide with the green ramp, nothing other.

Anyway, the thing works almost the same with much higher accuracy, I tested.
I quickly tested it again at 30 rpm. The velocity dropped a little bit more, but gained back.
I think it is not easy to replicate something like this in reality.


Dale,

I had to change the spring force at 30 rpm.
The spring force must be designed for Rpm (and weight mass), because at higher Rpms, the centrifugal force is also higher, which mean you need a stronger spring to return the weight to the inner position.
Things must be match correctly. I think it can be problematic to build something similar in reality, even more if you operate with higher Rpms. Please be very careful if you build such a "crazy" thing (), it can be really dangerous when you drive it at high Rpms.

Greg

[inroades]

    Hello Greg
I will be very careful, high rpm could give new meaning to a free weight room.
   Thanks again
    Dale