NEWS FLASH!! Fcdriver has a working wheel!!!!

[Grimer]

Grimer.
So, another "Now I see" moment. You can't mathematically prove your theory.

I have proved it to my satisfaction.

... I suspect when you revert to 3rd derivative mumbo jumbo it is to try to give the impression of not being stupid.

LOL. Well, one of us is being stupid. ;-)

I have publications which have been accepted by my peers to show that I'm not stupid. What have you got?

[Grimer]

A lookup table would be very useful.

How about length to centre of spherical bob = 20 inches

Diameter of bob = 2 inches

I fail to see of what value this is or what is to be gained in this discussion.
...

I'll try to explain.

Below is a diagram which is meant to illustrate the position of a pendulum bob at successive equal time intervals. The positions are pure guess work on my part. They show the fact that a pendulum moves faster near 6 and slower near 12 but they are not accurate. They are merely what you might call an artist impression.



I am trying to get a more realistic diagram.

You're a clever chap, Ralph. I'm sure you could provide one for me in no time. ;-)

[ME]

hmm, ok here's some new. Angle per time.
It lacks some data near 12-o'.
For all your manual labor I've precalculated the [x,y] in inches.

[ME]

I just mapped the angle somewhat onto a sigmoid-like function (I think 1 decimal accurate in degrees) - also works for negative t

Angle:=180*(1/(1+EXP(0.86862*t^2-5.6078*t))*2-1)
(perhaps unnecessary: for radians replace 180-->pi )

add:
duh....This one is symmetrical:
Angle:=180*(1/(1+EXP(-1.238116*t^5+1.670198*t^3-5,509243*t))*2-1)

[Grimer]

Well, I can't download your download for some stupid reason but that equation looks promising.

Later this afternoon I'll put it into my "graph it" program. That should do the trick.

Thanks very much for all your efforts. I'd click your greenie but when I look I find I already have. :-)

[ME]

These are the some lines in case of curiosity.
Formulas are better, but those above are curve fits - (added another one there).

Code: Select all

Time[sec]  Angle[deg]        x["]      y["]
0.8           173.183       2.374    19.859
0.78          172.558       2.59     19.832
0.76          171.875       2.827    19.799
...
0.04          20.036        6.852   -18.79
0.02          10.056        3.492   -19.693
0             0             0       -20

Thanx for your virtual extra greenie then :-)

[Fcdriver]

In changing the harmonic motion of lift to stroke, what do you get? Separating the two, and turning it 90 degrees. The rate of lift being a force against rotation, will equal 32 newtons, while the power stroke will equal 947 newtons.

[ME]

...what do you get?

Let me guess: a hidden easter egg?

[Trevor Lyn Whatford]

Hi FcDriver,

are you sure? that is a 29.59 to 1 ratio so with levers or gears or both, that is very large height differential between the power stroke and the lift stroke.

Edit, are you pumping fluid up and using fluid weights?
That's it tea break over back to the garage.

[Grimer]

I just mapped the angle somewhat onto a sigmoid-like function (I think 1 decimal accurate in degrees) - also works for negative t

Angle:=180*(1/(1+EXP(0.86862*t^2-5.6078*t))*2-1)
(perhaps unnecessary: for radians replace 180-->pi )

add:
duh....This one is symmetrical:
Angle:=180*(1/(1+EXP(-1.238116*t^5+1.670198*t^3-5,509243*t))*2-1)

The first equation worked well as you can see from the attachment. I didn't realize it started from the bottom until I was some way up.

I'll be able to get the values to the nearest degree which will be fine for my purposes. If I merely used an artist's impression some pedant would be bound to object. :-)

[Grimer]

.................................

LOL!

I've discovered the principle on which gravity mills work - but you're never going to believe me. :-)


"Big whirls have little whirls that feed on their velocity,

and little whirls have lesser whirls and so on to viscosity."

[ME]

Fractals are good !
Care to elaborate?

Who's Lewis Fry Richardson?

[Fletcher]

"The coastline paradox" re Franks whirls and twirls etc etc etc etc.

[rlortie]

For those fortunate to have access to Netflix: I suggest they watch the first four episodes of the series called "The Physics of Light"



http://www.netflix.com/watch/80068008?t ... d=80068005

[Grimer]

Fractals are good !
Care to elaborate?

Who's Lewis Fry Richardson?

If you click on your own link to wiki then you'll know as much as I do. :-)