Moderator: scott
Sorry about that... your right.Fletcher wrote:That's because you have gone over it a thousand times in your head in every detail & it is very familiar to you.
I didnt say the outer weights were "lighter" just... "out-er"...etjoe wrote:My doubts about this are similar to my doubts about Aldo's wheel (the 5 story high wheel in France). IMHO, the wedges that shift the lighter wedges to the outside will not keep the wheel in motion. I also think that when the wheel turns, the inertial forces will move the wedges to the wrong positions. I'm still gonna try it on the sim so I'll let you know if I get anywhere. In my wheel, I use a ratio to get an advantage, I'll try to incorporate some of that wisdom into deciding what the weights should be.
-e
So you animated it... with a gif generator?ovyyus wrote:Hi Oxygon,
I've animated your easyaspie diagram. All weights are assumed equal which means transition point is at 45deg rotation (equal weight falling and rising). Coupling of inner and outer weight pairs by whatever efficient means.
Unfortunately, no million bucks - it obviously balances out over a full cycle.
Bottom heavy? Yes, true... but it also makes it "side heavy"... all it has to do is turn it less than a quarter to cause the other sets to shift... I have done some math regarding this bottom heavyness... and it only comes "close to stall"... and this problem of "near stall" can be further alleviated by a series-connected design...Jonathan wrote: The inner weights that do not move radially are at all times making the wheel bottom heavy, and the energy used to shift the outer weights comes from having lifted those inner weights against the bottom heaviness, and letting them fall again as they pass the zenith (and nadir). But the energy to lift them against the bottom heaviness comes from the energy (radially) stored in the outer weights.
Sorry mate, I thought an animation might help make it a little clearer for everyone. Apparently I was wrong.Great so you animated it... What, with a gif generator? Thanx, but that can't be your evidence? How does it obviously balance out?
Oxygon wrote:Great so you animated it... What, with a gif generator? Thanx, but that can't be your evidence? How does it obviously balance out?
I am sorry for the "impetuousness" of the statement, I did alter it before you responded...ovyyus wrote:Sorry mate, I thought an animation might help make it a little clearer for everyone. Apparently I was wrong.
... Yes I have, but have you?... Perhaps we get different results?ovyyus wrote:The gif anim was taken from a cad layout. In this design you could simply measure the horizontal distance of the various weights from the axle line in order to ascertain relative balance across increments of rotation. I don't see the problem?
Will call this "Plan B"...Jonathan wrote:If you're going to the trouble, might I suggest this design? It seems simpler as it has no 3d motion, and you don't need any special joints. The round things are pulleys, the lines between them are strings, the black squares are weights connected to the strings, and the encompassing rectangle is some arbitrarily shaped frame with an axle through the little central circle.
EDIT
It just occurs to me that you don't even need the pulley on the inside of the curve, then the string will make a triangle shape, but it will work the same.
No mistake,... Slow and large is better... As I am sure these forces would interfere...jim_mich wrote:A Discovery... thanks to Oxygon
Two equal weights, one movable in and out along a spoke, the second movable side to side straight line along a cord (a trig. term, NOT a string). The two weights are interconnected to each other so when one move the other moves, each the same distance. Gravity will shift the weights at about 45 degrees of wheel rotation past top and past bottom.
The discovery... the wheel will be very slightly out of balance! The below calculation comes very close to equaling the OB (Out of Balance torque) found using a computer program that sums the torques at each 1/10 degree full circle.
A bigger angle produces a bigger OB so it is best to have the inner weight close to the center. The distance of the outer weight from the axle makes no difference.
I have NOT looked at inertia, centifugal forces, etc. Maybe they cancel out the effect? And I hope I've not made some type of mistake!
