Bessler's secret (probably)

[broli]

Forget it-------------------Sam

Thank you for your contribution. But please be more constructive in your contributions next time. Thank you.

[Robinhood46]

Something aint right in the simulation, i think.
The diameter of the wheel on my screen is 20 mm which gives 62.8 mm circumference. The Yellow circle rotates a bit over half a turn, so i think we can say 33 mm without exaggerating.
The blue rectangle only moves 24 mm.

The YouTube video Fletcher shows, doesn't show any slipping going on, and we can see because the plank has lines on it.
Why are we not seeing the same thing?

[broli]

Something aint right in the simulation, i think.
The diameter of the wheel on my screen is 20 mm which gives 62.8 mm circumference. The Yellow circle rotates a bit over half a turn, so i think we can say 33 mm without exaggerating.
The blue rectangle only moves 24 mm.

The YouTube video Fletcher shows, doesn't show any slipping going on, and we can see because the plank has lines on it.
Why are we not seeing the same thing?

The beam being pushed demonstrates how the cart rolls faster on the beam than it does on ground. This is only to demonstrate that there MUST be a velocity delta between the ground wheel and the "air" wheel.

As I said earlier, IF the upper beam now was ALSO fixed rigidly to the ground, the upper "air" wheel MUST slip against the upper beam for it to move forward, due to this inherit velocity difference we saw in the video. This slipping force then goes through the rigid body structure by following 3 simple rules and becomes a force/torque that propels the cart forward faster and faster rather than backward.

Gears, work on the operation of slip. Using a rack (for the ground and air board) and pinion gears for both ground wheels and air wheel. should be enough.

[Robinhood46]

I don't think we are seeing the same thing Broli.
The trolley rolls faster than the beam, because the upper wheel rotates with it's perimeter moving at exactly the same speed as the moving beam, no slipping, and the trolley moves at the speed of the perimeter of the little wheels, which is faster because the upper wheel is turning a smaller diameter shaft than the little wheels perimeter.

The moving of the beam moves the trolley, and the rotating of the wheels causes the trolley to move at a greater speed than the beam, as Sam said the little wheels are driving the big wheel. The driving of the big wheel by the little wheels is what causes the trolley to move a greater distance than the beam.

[Sam Peppiatt]

If the little wheels were on top of the cart and the big wheels were on the bottom, it would move the other way. If the wheels were all the same size the cart wouldn't, move in either direction----------Sam

[Robinhood46]

If the little wheels were on top of the cart and the big wheels were on the bottom, it would move the other way.Sam

Sam, would it not move in the same direction, but at a slower speed than the beam?

[johannesbender]

An Inversion..

[Sam Peppiatt]

Hi Robinhood!!
Have I got it wrong? The beam moves the trolley. You are right about that, which is the key to it. What I'm thinking is; now the little wheels would be turning really fast and would drive the big wheel the other way, at the same speed as before.

I think he, broli, is right; it is amazing----------------Sam

ETA Did I guess right?? I guess it's the little wheels that decide.

[Robinhood46]

It looks like I'm the one who got wrong Sam.
I did have my doubts, which is why asked, and I'm still trying to grasp what's going on even with the simulation showing what's happening.
It would have been better if veritasium had turned it over to show it going backwards.

[Sam Peppiatt]

Hi Robin, Yea, it will warp your gourd---------------Sam

[johannesbender]

Imagine i take this spool and thread example and i attach a rod only to the end of the thread and push the rod to the right instead of pulling the thread to the right .

https://youtu.be/qebMrMt4240

[broli]

As I asked earlier. Does wm2d support sliding friction? If not then all you will see is that there indeed is a velocity difference between the ground and air beam. You must fix both to the immovable earth but if the air wheel cannot slip on the air beam, then it will lock up and nothing will happen.

Fix both ground and air beam. the wheels on the ground must not slip only role on the ground but the air wheel must SLIP SLIP SLIP.

If wm2d cant do slip then all you have left is to apply a fixed force at the top of the wheel imitate friction. Sorry that I am a bad "teacher". Just follow the 3 rigid body rules and you should be able to follow any force and its torque on the system. Same goes for the above Rope/Spool example. Very easy to analyze. I am going on severe sleep deprivation as well so I might slip up myself here and there so I apologize in advance and might return to amend mistakes when my head is more clear.

[Fletcher]

As per my original sim if we use friction drive-trains there are problems with the cart gaining velocity in forward direction n.b. the video was a friction drive .. if we use gears from the large friction-contact wheel to just a minimum of ONE axle of a smaller wheel undercarriage it accelerates away as per the video ( see jb's sims ) .. gears in WM are frictionless as far as I can tell ..

n.b. as much as I'd like to be able to build a rack and pinion system for force transfer I just don't know how to do that in WM so it is unfortunately not an opinion for me to sim ..

The explanation imo seems to be as per jb's "spool effect" video where, like water runs downhill the large wheel takes the path of least resistance ( i.e. spins backwards CCW while wheels go CW ) - because the axle of the undercarriage has a smaller radius than the actual wheel it is attached to this modifies the applied forces by a type of MA ratio ..

However, when all said and done .. in the video re. hand-held beam substituting for air pressure and wind speed, and the large wheel substituting for the swept propeller blade area, connected via a gear train transmission to the undercarriage wheel sets of the Black-Bird, then we have a Classical Physics approximation for analogy purposes .. BUT - iinm, and as I simmed, the Work Done by the wind speed and force analogue is always greater than the KE gain of the DWFTTW cart n.b. the cart is not in "PM Mode" with a greater KE than the wind force x distance ( Work Done ) done on it ..

Outside of sim world there are all sorts of frictions to be overcome, including head-on air drag etc limiting down-wind speed to about 2.8 times wind speed ( average ) and about 1.8 times wind speed heading into wind, iirc .. this can be tweaked ( speed, not Total KE ) by a lighter cart setup and experimenting with the undercarriage axle diameter to wheel transmission diameter ratio to optimise cart speed compared to wind speed .. but its KE is not, as far as I'm aware, greater than the Work Done on the cart by the volume of air in contact with it, afaik ..

Usual caveats Broli - good luck and I hope your 3D model effectively proves your arguments, and my analysis is patently wrong - best -f

Sim attached ..

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[broli]

Hi Fletcher thanks for doing the Sim work. But as I said before multiple times. The top beam must remain FIXED or else there indeed is no extra energy.

When it's fixed and the cart is given a small initial push by "gods hand" the top wheel MUST slip on it and the slip frictional force from that STATIONARY beam now acts to propel and accelerate the cart forward. So for the beam, force over distance is 0 because it remains stationary (from Earth's perspective) yet it "pushes" the cart forward continuously. This happens because of the unique nature of slip frictional force and the fact the earth which the beam is fixed to is massive and "immovable".

Slip guys how often should I shout this out. Please get it you need It to slip.

Again thank you for using your precious time validating this in wm2d.

[Fletcher]

The YouTube video Fletcher shows, doesn't show any slipping going on, and we can see because the plank has lines on it.

The beam being pushed demonstrates how the cart rolls faster on the beam than it does on ground. This is only to demonstrate that there MUST be a velocity delta between the ground wheel and the "air" wheel.

As I said earlier, IF the upper beam now was ALSO fixed rigidly to the ground, the upper "air" wheel MUST slip against the upper beam for it to move forward, due to this inherit velocity difference we saw in the video. This slipping force then goes through the rigid body structure by following 3 simple rules and becomes a force/torque that propels the cart forward faster and faster rather than backward.

Gears, work on the operation of slip. Using a rack (for the ground and air board) and pinion gears for both ground wheels and air wheel. should be enough.

Umm .. actually I was fixated on why the friction sims weren't working the same or similar to the geared versions of the carts - then, why anybody would think a "Mr Hand" moving a beam would be a suitable analogy for Bernoulli's Low Pressure Theorem of Lift and Drag forces in combination with momentum transfer from Angle of Attack propelling an aircraft upwards and the DWFTTW carts forward ..

Shame I can't make a sim rack and pinion arrangement - I think I've tried before and got nowhere - maybe someone else knows how to do this and can make a sim model for you to test your theory further ..

Otherwise good luck with the 3D printed model Broli .. something like this ( free/extra-energy ) is always going to need a real-world POP one way or another I feel ..