Besslers prime mover and its enabler.

[SHADOW]

Bonjour Graham,
C'est ce que tout utilisateur d'Algodoo a pu constater, si le mouvement n'est pas flagrant c'est qu'il y a un beug.

Hi Graham,
This is what any Algodoo user has seen, if the movement is not obvious is that there is a beug.

[Roxaway59]

Hi Shadow, yes I've noticed odd jerking movements coming from both ropes and springs. It improves if you take the accuracy up and I mine was on 4800 but it was still doing it. The jerking movements end up putting energy into the system. I don't understand why the makers don't sort such an obvious flaw out.
Graham

[phj]

Hi Shadow and Roxaway,

Algodoo is originally developed by Emil Ernerfeldt, a Swedish software developer. The program was launched under the name "Phun" in 2008 but was later rebranded as Algodoo.
The latest version I'm aware of is version 2.1.0, released back in 2013. While the program still functions well for most purposes, there haven't been official updates since then, leading to speculation that development may have stalled.

PHJ

[Roxaway59]

Fletcher I have another overbalancing mechanism for you to check out if you will. Once again its a very close thing but I'm hoping this is something real and not just giving the impression of working. I wont show it yet till I've had a chance to replicate it in WM2D to see how it behaves. If all is well I will post it tomorrow for you to check.
Graham

[Fletcher]

no worries ..

[Roxaway59]

I spent time today simulating in Algodoo and WM2D. Basically the simulations did completely different things. Algodoo was suggesting that I had found some mechanical advantage and WM2D was saying I hadn't.

To cut a long story short I've done a basic simulation in Algodoo to highlight what must be another bug. Basically if you run the simulation you will see the two mechanisms do different things when actually they should overbalance in the same way.

in all honesty Algodoo is not a simulator its a joke and I think I will be only using it for pictures from now on I'm really disappointed.
Graham

[Fletcher]

Hi Graham .. I took a quick peek at your Algodoo sim above ..

I haven't reproduced it in WM as yet ..

My initial thoughts about why they behave differently is this ..

Firstly the parallelogram setup has 2 centers of rotation ( CoR ) - these functionally combine into 1 system CoR which is half way between the 2 - so it is the horizontal distance from this functional CoR that matters when calculating Leverage factors ..

Secondly ( an this is a common misconception that is often not understood ) Leverage distances itself does NOT matter in creating Torque ( force in a curve ) .. ALL that matters is which mass can lose the most GPE ? - this is the VETO - the system will then rotate in the direction that 1 mass loses more GPE than the other gains in the same time period .. PERIOD ..

Try it in WM and see if you get a similar result - meter the y coordinate of GPE for each mass etc, and compare ..

[Roxaway59]

To be honest Fletcher I don't know some of your terminology. When I tried the same mechanism in my WM2D it needed the blue weight to be heavier and it seemed to behave as though the twin pivots didn't matter. If there's any chance I read it wrong I need to know of course. Give me a minute and I will post what I was seeing in Algodoo then later I will get what I did in WM2D and post that for you to check.
Graham

[Fletcher]

"Veto" - a constitutional right to reject a decision or proposal made by a lawmaking body (not a democratic decision) - aka - overriding rule ..

"Period" - full stop - aka - without further discussion ..

[Roxaway59]

Here is the version in Algodoo. The blue weights are able to overbalance the yellow ones and the mechanisms can fall into the positions shown.

Run the motor so it turns a little then turn the motor off.

Graham

[Roxaway59]

I did this to increase torque.
Graham

[Fletcher]

I can see it is frustrating you - as you have said Algodoo is ok for planning a build but not for predicting behaviour reliably - build the simple version in WM and post it up - I will add the metrics on GPE changes etc so you can see what is happening at a glance .. then you can save the file and add your own metrics (copy & paste) on future run tests of devices you are investigating ..

[Roxaway59]

Here is the one I did in WM2D when I discovered the problem. If you can check it in your more modern one that would be great. It does act a bit odd in my version because it doesn't like these mechanisms that cross over. Air is on low and accuracy fairly high.
Graham

[Roxaway59]

I think what got me about it Fletcher is that I had gained some confidence in Algodoo doing somethings accurately and I was expecting WM2D to behave the same way.

It kind of remains me of that Monty Python sketch. What has Algodoo ever done for us?

Well you can make good drawings.

Ok but apart from drawings what has it ever done for us?

You can resize things easily.

Alright but apart from resizing things and making good drawings what has Algodoo ever done for us?

Its free!

Ah shut up!

I'll be ok I just need to stop relying on that program too much.
Graham

[Tarsier79]

This image seems to me like you understand what should happen. The left and right are equivalent, and this demonstrates what often happens with multiple pivots. It also demonstrates in a way how to simulate a 3d object in a 2d space...

If you look at the right image, you can imagine it is a 3d image of the one on the left with your viewpoint looking through the center with both axis lined up.

Also, I second Fletcher's statement, whichever weight will lose more PE (mass x height) will move downwards.