What else can a cell phone do
oregon ? Interesting.
Sometimes recording and analyzing vibration data is more complicated than physically building prototype units.
A diving board at a swimming pool is a great basic vibration model.
The simple modification I did to the Vibrasonic could easily be compared to a diving board with man bouncing on it at steady rate.
So I used the diving board analogy because it is slow and understandable.
I lowered the center of gravity of the new hopper closer to the vibration pivot point and made the hopper heavier.
So the new hopper was bottom heavier and the stones sat lower/closer to the vibration generator.
--OR-- comparing to diving board:
Moving the bouncing man back to the center of the diving board where the travel is shorter and the(acceleration) reversals much gentler.
Oddly, most vibrating systems have a natural frequency as does a diving board.
If you bounce on the end of the diving board or at the center, it will be the same amount of bounces per minute.
But the travel is much further, the velocity faster and the acceleration higher at the end of the diving board.
Instability = biggest fear in modification:
So no measurements were really necessary. It was a given that moving the hopper center-of-mass closer to to the vibe source will have this guaranteed outcome **** if no instability occurs.
Motor driven systems with springs can be way more unstable than a diving board.
If weight was added further from the vibe source you stood a chance of skipping vibrations because the vibe source may not be able to handle the extra load due to springs in system.
Or too close and you may have fallen into a higher frequency situation which would likely cause higher reversal accelerations and damage soft material. Again, springs are tricky.
Failures due to instability was my biggest fear in modifying the Vibrasonic.
Two different modified hoppers and neither became unstable(judging from polishes on glass) telling that a stable sweet spot has been arrived at. Luck and more luck.
Keep in mind the Vibrasonic is a flexible vibration machine as it can be run with 8-12-14 and 35 pound hoppers.
No other vibe on the market has this stability bandwidth. So it was chosen for this project.
When it comes to cell phone apps I am about helpless. I am seriously challenged by them. (old school background).
But they did shove vibration theory(or mechanics) down our throats in engineering school.
And our rock vibes are rather simple as far as vibrating systems are concerned.
Particularly the Vibrasonic because it operates on 2 dimensional vibration as opposed to donut shaped hoppers that are full 3 dimensional vibration devices.