I've not read much on this, but I just found Naudin's page. 13% output gain, but 34% losses regardless.
So, how do we:
A- reduce losses to below 13%?
B- if possible, increase the gain some?
Some observations, and facts:
- steel ball used is very small, just 16g.
- air friction increases exponentially with speed, rolling resistance proportionately with speed and weight
- air friction is relatively strong on smaller objects, due to lower mass/frontal surface ratio.
Ideas to reduce losses:
- first and foremost : upscaling! Mass/surface ratio will impove (3rd power of 3D body divided by 2nd power of width*height).
- steel is not very high density : gain might gave been better with Tungsten (unless that's magnetic? would need to check). This would further reduce Mass/surface ratio.
- golf ball dimples
- Embrace or fight gyro effect? A heavy core could sit inside a lightweight wheel, to have low rolling friction to gyro ratio. It would move more air though.
- Once there is a good setup : vacume chamber. To do only when calcs say it will make a runner.
- steeper ramp going up (where Naudin measured output distance). A steeper ramp is shorter, ball spends less time on it, less time being exposed to the average (middle between zero and max speed) speed. Helps even better for the air resistance, by converting top speed (top friction) into height.
- Of course, the steeper and shorter up-ramp should not cause an unwanted negative magnetic effect.
- Setup should be mounted firmly on a no-flex-what-so-ever base. Like a concrete pole used in building fundation. No spacers at all, base directly place inside.
- Very hard surfaces. Special pollish and hard coating on the ball to fight rolling friction.
- Speed variances in the ball when in contact with the surface, together with grip friction somewhere between zero and infinite, will result in unwanted losses. Angular momentum makes the ball slide. When it's ultimately slippery, no spin is lost or gained, ever. When it's high enough, little or no spin or urge to spin up will be transferred into heat.
- 2 same height SMOTs in series. No point in trying otherwise, right? The attraction of the first magnet of the SMOT may help overcome the last bit of vert. The ramp could then be curved.
- A simple see-saw could prove that placing the ball on the SMOT entry takes no more energy than is put into it in potential energy (the height.).
- In a vacume setup, I would use a greater drop behind the smot. Much greater. This way, the horizontal distance to be travelled from the first SMOT to the second, or even back directly to the entry of the first, can be done at high-speed. The exponential air drag won't be there at all. Time travelled rolling (friction) would be minimized (high speed, same distance). Then, with the great height, the gain would of course be a smaller percentage, something to not forget.
- This favors a really big ball, rolling up and down just 20mm each time for instance. Low speeds, low air friction.
- Lest not forget, the interface shape of the ramp with the rolling/falling ball is never perfect, can always be optimized.
Any ideas welcome, as well as your experiences or links to setups better than Naudin's.
Thanks,
J
I think it CAN be done. It's just not supposed to be easy.
Has anyone ever seen a similar SMOT that offered greater gain?