Power ball lost power

[The Force]

One thing which pops up in my mind is a possible difference in friction between the upper surface and the lower surface of the inner track in which the axle rolls. For best operation it may be required that both surfaces have a certain friction, but it may still work (but to a less extent) if only one surface satisfies this requirement as long as the axle is pressed against the better surface.

And then I am thinking, maybe it has to be that surface which faces is closest to ground as that one is the one to which the rotor axle is pressed by the gravity force.

But then, I am thinking, the problem should be reversed when you hold the powerball upside down, in the air. And this is an experiment I did not do yet.
Interesting one.

One question which is still open in the above story is WHY a surface of a track suddenly gets slippery.

Gosh...you would almost start to think that I have a scientific background .

Regards,

The Force

[LTLFTC]

One thing which pops up in my mind is a possible difference in friction between the upper surface and the lower surface of the inner track in which the axle rolls. For best operation it may be required that both surfaces have a certain friction, but it may still work (but to a less extent) if only one surface satisfies this requirement as long as the axle is pressed against the better surface.

And then I am thinking, maybe it has to be that surface which faces is closest to ground as that one is the one to which the rotor axle is pressed by the gravity force.

But then, I am thinking, the problem should be reversed when you hold the powerball upside down, in the air. And this is an experiment I did not do yet.
Interesting one.

One question which is still open in the above story is WHY a surface of a track suddenly gets slippery.

Gosh...you would almost start to think that I have a scientific background .

Regards,

The Force

Once it gets going there will be one axle on one surface and one on the other it wouldn't matter where it is orientated in space the force of the spinning will over come any gravitational pull.

[The Force]

Once it gets going there will be one axle on one surface and one on the other it wouldn't matter where it is orientated in space the force of the spinning will over come any gravitational pull.

I know what you mean, but do not know whether your right as far as the forces is concerned. Or saying it differently, maybe gravity does play a role.
After all, whether you like it or not, some powerballs do have a preferred spinning direction, and if gravity would not play a role this could not occur, or did I miss something here?

Anyway, I'll figure out.

Regards,

The Force

[LTLFTC]

After all, whether you like it or not, some powerballs do have a preferred spinning direction, and if gravity would not play a role this could not occur, or did I miss something here?

Anyway, I'll figure out.

Regards,

The Force

I definitely agree with that. I read a thread where Akis only used a ball in one direction only then tried to spin it the other way and it was way slower. Whether or not it is faster in it's preferred direction than a ball that has been spun both ways??? I still think that gravity has no say in the matter over 5 or 6k. The spinning forces are just to great.
I had a new ball where I only held it in one position and spun it in one direction. It got almost an elyptical shape to the track wear but that was due to thae fact that I input the power into the same spot in the system all the time. It was never any faster than any other ball either

[The Force]

I definitely agree with that. I read a thread where Akis only used a ball in one direction only then tried to spin it the other way and it was way slower. Whether or not it is faster in it's preferred direction than a ball that has been spun both ways??? I still think that gravity has no say in the matter over 5 or 6k. The spinning forces are just to great.
I had a new ball where I only held it in one position and spun it in one direction. It got almost an elyptical shape to the track wear but that was due to thae fact that I input the power into the same spot in the system all the time. It was never any faster than any other ball either

I think it must be either the gravity playing a role OR (I thought about that just a minute ago) the friction experienced by the axle is rotation direction dependent (brilliant finding ). Btw, gravity surely plays a role at low rotation speeds.

The latter seems possible to me. Just imagine a surface having a sawtooth shape with a very very weak slope. If you role an axle in the direction experiencing the weak slope the friction is much less than in the opposite direction having very very steep edges.

Now some of you will say that it is nonsense that the surface has a saw tooth shape. I may agree with that, but now imagine that there is only one such tooth on the innertrack. The principle still works I think.

And maybe there is an even further effect (going in the opposite direction ).

NOTE: the radius of the axle is much higher than the heigth difference caused by the tooth/bump, otherwise the powerball won't work at all.

1) When the rotor axle hits the steep slope it will be "launched" a bit such that during a fraction of a second there is no contact between the axle and the surface (and thus less friction and less accelleration).

2) When the rotor spins in the opposite direction it will hit the weak slope which will not make the axle get launched too much (more contact), which means higher friction, and higher acceleration

Maybe the latter is still effectively reducing the maximum speed compared to a flat surface, but we were trying to explain preferred directions of the powerball remember ).

Gosh...I seem a bit talkative on the forum lately. Is there a monthly prize for that too ?

Regards,

The Force

[LTLFTC]

I think it must be either the gravity playing a role OR (I thought about that just a minute ago) the friction experienced by the axle is rotation direction dependent (brilliant finding ). Btw, gravity surely plays a role at low rotation speeds.

The latter seems possible to me. Just imagine a surface having a sawtooth shape with a very very weak slope. If you role an axle in the direction experiencing the weak slope the friction is much less than in the opposite direction having very very steep edges.

Now some of you will say that it is nonsense that the surface has a saw tooth shape. I may agree with that, but now imagine that there is only one such tooth on the innertrack. The principle still works I think.

And maybe there is an even further effect (going in the opposite direction ).

NOTE: the radius of the axle is much higher than the heigth difference caused by the tooth/bump, otherwise the powerball won't work at all.

1) When the rotor axle hits the steep slope it will be "launched" a bit such that during a fraction of a second there is no contact between the axle and the surface (and thus less friction and less accelleration).

2) When the rotor spins in the opposite direction it will hit the weak slope which will not make the axle get launched too much (more contact), which means higher friction, and higher acceleration

Maybe the latter is still effectively reducing the maximum speed compared to a flat surface, but we were trying to explain preferred directions of the powerball remember ).

Gosh...I seem a bit talkative on the forum lately. Is there a monthly prize for that too ?

Regards,

The Force

Sound feasible. You'd have to think on a microscopic level it would wear the track kind of like a gravel road with corrugations as you said a gradual slope and a steep drop. If you went both directions it would tend to have gradual slopes both ways. I like your thinking

Like a corrugated road though the steep drop tends to wear more and the bumps become more pronounced, meaning you will hit the steep bit with greater force as the bumps become bigger slowing down the forward momentum. If you spun in both directions it would wear more evenly

[Adrena1in]

In the cases where I've had a Powerball which is fine and easy to spin in one direction, but feels resistent and is slow in the other direction, I don't think it has anything to do with the inner tracks...I think it's down to the support band.

So what I'll do is run some tests to make sure I know definitely which direction on a Powerball is best, and then I'll remove and reverse the support band.

As for Gravity, Dennis once pointed out that the side of the rotor with the counter-weight will be slightly heavier, so to get a Powerball started it would be sensible to make sure that side of the rotor rolls along the lower surface initially.

But at anything over about 3k the gyroscopic torque is going to push the axles so hard into the tracks that gravity won't play a part at all.

[The Force]

In the cases where I've had a Powerball which is fine and easy to spin in one direction, but feels resistent and is slow in the other direction, I don't think it has anything to do with the inner tracks...I think it's down to the support band.

So what I'll do is run some tests to make sure I know definitely which direction on a Powerball is best, and then I'll remove and reverse the support band.

As for Gravity, Dennis once pointed out that the side of the rotor with the counter-weight will be slightly heavier, so to get a Powerball started it would be sensible to make sure that side of the rotor rolls along the lower surface initially.

But at anything over about 3k the gyroscopic torque is going to push the axles so hard into the tracks that gravity won't play a part at all.

True!!! Apart from friction between the axle and the track, there is also the friction of the rotor supportband with the track. However, I can hardly imagine that this plays any role, because the rotor supportband is in lying loosely in the track and its friction with the track should be as small as possible. If your theory is correct then the friction between the support band and the track would need to relatively large in order to influence the accelleration of the rotor.

Regards,

The Force

[amc]

It is the friction between the support band and the track that generates the accelleration. I have done a simple test to demonstrate. At first i thought i would gain more torque if i oiled the support band to the track. BEEERRR guess again ... After that, no way to accelerate anymore. On http://www.powerballs.com/faq.php?id=14 i saw the Faq about oiling a powerball. Worst idea ever. So i cleaned it and grinded some salt on the track, thinking this would increase the resistance of the band to the track. Since then, everything went back to normal. Besides, even if the band lies loosely on the track, while accelerating, one side of the band on each side is pushed against the track and resistance is increased. And i would think the pushing increases with speed of the rotor.

Edited to change link.

[Adrena1in]

It is the friction between the support band and the track that generates the accelleration.

Actually it's the friction between the rotor axle and the track. This is where people go wrong in thinking it needs oiling...so that the support band will slide easily on the track, not realising the rotor axle also then slides rather than gripping.

The support band just keeps the rotor centrally within the casing, and keeps the axles in position on the tracks.