Calling on Fletcher and Ovyyus

[broli]

If you keep on banging your head hard enough one of these days something interesting might fall out of it...that's a no brainer.

[nicbordeaux]

Yo Broli, thought you'd been abducted by them aliens, good to see you here ;-)

Problem with all you guys, lovable as you are, is that regarding proof, you're worst than overeducated school teachers : you want Father Christmas trussed and handcuffed with his pants down delivered to your doorstep. Even then you won't believe he's real.

[Tarsier79]

The heavy mass is the one moving vertically?

I disagree with Fletcher on the point he made about the point of rest, or the keel point. If there is a gain in PE at any point in time, you are a winner, if you can take advantage of that particular moment(providing there is no preload against springs etc). Also, angles etc are of no consequence if there is actually a gain in PE in the whole system. What you are attempting, is to raise PE on a near stationary wheel, then that PE is transformed to KE via rotaion of the wheel, till 6:00 when you again lift PE. If you can vary the speed at which this occurs then all the better.

What you have to conclusively prove, is that there is actually a gain in PE, from a fixed position. It sort of looks like there is, but it is difficult to be sure.

[ruggerodk]

Dear Nick,
I follow your experiment with greatest interest. Keep the video flowing ;-)

Found something (not at all similar) that are a bit in the same area: a double pulley pendulum
It might have youre interest...

http://paer.rutgers.edu/PT3/experiment. ... &exptid=60

regards
ruggero ;-)

[nicbordeaux]

The heavy mass is the one moving vertically?

I disagree with Fletcher on the point he made about the point of rest, or the keel point. If there is a gain in PE at any point in time, you are a winner, if you can take advantage of that particular moment(providing there is no preload against springs etc). Also, angles etc are of no consequence if there is actually a gain in PE in the whole system. What you are attempting, is to raise PE on a near stationary wheel, then that PE is transformed to KE via rotaion of the wheel, till 6:00 when you again lift PE. If you can vary the speed at which this occurs then all the better.

What you have to conclusively prove, is that there is actually a gain in PE, from a fixed position. It sort of looks like there is, but it is difficult to be sure.

I think Fletcher's point ref the possible hand held moment before release where rotation of the keeled OB to 3 or 9 might be restraining or pulling on the pendulum arm (a pretty big mass in it's own right), therefore adding or subtracting ke from the system... is perfectly valid. Which is why I have two other setups now, one is a "Newton's ball" type launch where a mass imacts the OB weight to set the whel going; the other one is a retractable (sliding) arm from the back of the stand, which holds the pendulum arm stationnary, and at the same time is a platform on which the OB weight rests at "3" position. Withdrawing this very lubricated "lease" means the setup is released without interference. In both cases the results are consistent with the first vids, eg there is gain. Gain at the end of energy expenditure, eg the heavy mass moving vertically gains height, which compared to the height lost by the OB weight in drivr weight is around 1.7 X. That's theoretically enough to relaunch the system. Regarding preload other than gravity, eg springs or else, there is nothing. The gain is captured by a spooling system, simply shortening the suspension line of the big mass.

Just spent the afternoon welding a big stable setup with back board to put graduations on, must have that silly lcd mask set wrong because splitting headache and sore eye...

Modifying speed ? Sure, one magnet on wheel, one on the pendulum arm, N/S opposition. When the two mags start interacting, there is a disting speedup, slowdown, then a speedy eject. Which means more oomph because of the jerky movement is transmitted to the pendulum arm.

BTW, all this stuff goes back to early days mucking around with bike wheels and oscillators, like http://www.youtube.com/watch?v=182feHKEB7U .

Anyway, thx for the encouragement :-)

[nicbordeaux]

Dear Nick,
I follow your experiment with greatest interest. Keep the video flowing ;-)

Found something (not at all similar) that are a bit in the same area: a double pulley pendulum
It might have youre interest...

http://paer.rutgers.edu/PT3/experiment. ... &exptid=60

regards
ruggero ;-)

Thx ruggero. That is an interesting vid. The variation in string tension shows why you can spool-shorten line and get overall com raise in more systems than one. The spooling can be system driven, or gravity driven if a counterweight is attached to the pulley wheel(s).
The system we are discussing is very elementary and wasn't my aim really, it already existed in more complex forms. Still, it's probably going to be easier to show clear results than by using mechanical advantage to bung a supersonic bouncy ball from a driven wheel ;-) Or to swing a golf club with enough velocity to get a decent drive.

Nick

[Bill_Mothershead]

Dear Nick,
I follow your experiment with greatest interest. Keep the video flowing ;-)

Found something (not at all similar) that are a bit in the same area: a double pulley pendulum
It might have youre interest...

http://paer.rutgers.edu/PT3/experiment. ... &exptid=60

regards
ruggero ;-)

Thank you for the video.

Here are two that are related:

http://www.youtube.com/watch?v=QFTnVdWqevc

http://www.youtube.com/watch?v=bCBGhjJ-7eU

[ruggerodk]

Dear Nick,
Just for the fun of it, it seems like your March Pendulum get its extra force, by combining the g-force when both pendulum and weight are at 6 (or thereabout): At that point you have the most tension.

A racket on the lifting side could have merit, as in this simple gearing of a double pulley pendulum. (Actually it's a kind of reverse clock-arrangement)

Best
ruggero ;-)

[nicbordeaux]

Well ruggero, there's a whole world of stuck-in-a-rut crackpots out there calling improbable devices (my name/device), guess I deserve to name one after myself too :-)

The force at 6 or vertical... you are right. Except I don't think I'm tapping into it seriously right now. This is the force which acts on the whole device, stand included, at rest. Set that on a spring/slider and you have an additional amount of movement to use. Or there is a variant (tested) where you have your 10 kg stand on a piece of round steel tube so that it can rock back and forth. This I've tried, it's OK. If the stand is line-linked over pulley to a balanced (10+ kg) weight , it also acts like the main device with the big weight over pulley to 665 gram weight. So with your 100 grams you're setting an enormous amount of weight in motion (10 kg+device and attached weights, and additional 10+ kgs). Better load the scatter guns and uncover the well, the MIB should be calling shortly if the mythology is correct...

I'll give your geared ratchet wheel a try, a small bike wheel is already ready: it has a freewheel on the hub, and fitted to freewheel a 52 tooth chainring.

The simple description of the way this device works, and why ? Easy, it's a person on a swing. The OB wheel is the swing seat with the person on it, the pendulum arm is the swing ropes. The masses over pulley wheels don't change the fundamental mechanics.

Still haven't quite figured out why it only works when the OB weight is below three and 9, any higher and the force isn't manifest as big movement of the arm.

Edit : wasn't that character bessler worried about people not giving his device too fast a start impetus ? That fits. And the swing on the toy page. Maybe he was using some similar mechanical behaviour ?

[nicbordeaux]

I have now discovered that a standard farm implement will lift 100 kgs over 1 mm with an input of 150 grams over 5 cms.

Now, eyeballing those figures says 100 000 grams over 1 mm compares pretty favourably to 150 grams over 500 mm.

Two to one ? If it's only that much, it's not worth pursuing. Vid later this week probably. But for sure, using a billiard ball and cue 1000 X whilst sitting on a platform should get a rise of 2 meters ?

[ruggerodk]

Nick, whatever you're smoking my banker should take a puff or two before I withdraw money ....5 cm is not 500 mm but 50 mm
8-)

[nicbordeaux]

Not smoking anything particular ruggero, just trying to manage many things at the same time, and still have fun with this gravity stuff :-)

That makes the ratio utterly ridiculous . In this case, there is no explaining it away as experimentor error, which is a right pain 'cause now I have to do the vid and ask you lot what the heck is going on... I sit on a platform weighing 10 kgs, I weigh 75 kgs and I'm carrying a canon ball weighing 15 kgs. Swinging a 100 gram mass just once , attached by tether to the most sensitive part of the contraption makes the 15 kg plate and the remaining junk rise one mm, measured by a digital caliper gauge being pushed up.

Is it conceivable that on a atwoods 100 grams could make 100 kgs budge even a mm ? Count inertia and friction.

Maybe you are right, somebody has been lacing my weed ...

Edit : lest anybody get any wrong ideas ref "attaching 100 gram to most sensitive part of the contraption" , neither I nor the canon ball count as contraption.

[nicbordeaux]

Edited: Information posted by mistake.

[Tarsier79]

If the farm implement is using a spring or hydraulics to maintain a certain height of the tool...

Think about a single flipping weight in the centre of a wheel. You need to lift it against gravity twice per rotation for maximum torque. So will your farm implement work exactly the same, and not lose vertical height if you flip it upside down?

[nicbordeaux]

It's a pair of farm scales Tarisier, used for weighing pigs I'd guess. The plate of wood you stand the pig on (or a person) will sink a couple of mm whilst the arm with sliding weight travels 5 cm total either side of balance point. Loads of leverage. There is a simple explanation, just haven't found it yet. Amusing, not anything about to revolutionize physics. Still, the figures given are correct, so there is a interpretation mistake somewhere...