Ideas on How This Exhibit was Designed?

In summary, the ball bearings in this video bounce really well off of steel glockenspiel bars, but that wasn't the case when I tested this myself with a stainless steel ball bearing and a steel glockenspiel bar.
  • #1
WorldWiz
19
0
TL;DR Summary
How do the ball bearings in this video bounce so well off of steel glockenspiel bars?
Watching this exhibit from years ago () led me to think that ball bearings will bounce really well from steel glockenspiel bars, but that wasn't the case when I tested this myself with a stainless steel ball bearing and a steel glockenspiel bar. Granted, I was just propping up the bare glockenspiel bar with two finger spaced out at the two nodal points (ie holes) of the bar, but I still got <5% bounce height, so I think there's probably another factor that I'm not considering that's making the exhibition work.

My best guess is that the ball bearings in the video are made out of a lighter material (hence I chose this subforum) like titanium, maybe, but does anyone else have any ideas on this? Perhaps the type of material of the glockenspiel bars is also important, if it's a stiffer material that won't absorb/dampen the energy carried in the ball bearing? Thanks.
 
Engineering news on Phys.org
  • #2
WorldWiz said:
Granted, I was just propping up the bare glockenspiel bar with two finger spaced out at the two nodal points (ie holes) of the bar, but I still got <5% bounce height
You were supporting the metal bars with your fingers? That damping is probably where the energy got dissipated. Still, a 5% rebound is remarkably low...
 
  • Like
Likes WorldWiz, Hornbein and russ_watters
  • #3
WorldWiz said:
TL;DR Summary: How do the ball bearings in this video bounce so well off of steel glockenspiel bars?

...Granted, I was just propping up the bare glockenspiel bar with two finger spaced out at the two nodal points (ie holes) of the bar, but I still got <5% bounce height,...
The bars will need to be held down onto a hard knife edge, at their exact nodal points, to prevent loss of energy at each fulcrum.
WorldWiz said:
...Perhaps the type of material of the glockenspiel bars is also important,...
Yes. Select a material that will ring like a bell, test any small sample you find.

Some materials contain big crystals, of differing structural chemistry, with significantly different acoustic impedance. Those materials sound dull and do not ring. Metal alloys are like rocks. Most rocks sound dull when you hit them, but some will ring efficiently if they are not fractured.
https://en.wikipedia.org/wiki/Phonolite

Avoid some stainless steels, aluminium, zinc or lead alloys that have been allowed to cool slowly. Select instead hard alloys that are close to eutectic composition, and that have been cooled rapidly.
https://en.wikipedia.org/wiki/Eutectic_system

When bouncing a ball, surface finish will be important. You might chrome plate the bars, or fine polish the surface of a material that will not oxidise. You don't want to go dropping a ball onto a surface of soft oxide or powder.
 
  • Informative
  • Like
Likes WorldWiz and berkeman
  • #4
Baluncore said:
The bars will need to be held down onto a hard knife edge, at their exact nodal points, to prevent loss of energy at each fulcrum.

Yes. Select a material that will ring like a bell, test any small sample you find.

Some materials contain big crystals, of differing structural chemistry, with significantly different acoustic impedance. Those materials sound dull and do not ring. Metal alloys are like rocks. Most rocks sound dull when you hit them, but some will ring efficiently if they are not fractured.
https://en.wikipedia.org/wiki/Phonolite

Avoid some stainless steels, aluminium, zinc or lead alloys that have been allowed to cool slowly. Select instead hard alloys that are close to eutectic composition, and that have been cooled rapidly.
https://en.wikipedia.org/wiki/Eutectic_system

When bouncing a ball, surface finish will be important. You might chrome plate the bars, or fine polish the surface of a material that will not oxidise. You don't want to go dropping a ball onto a surface of soft oxide or powder.
Thanks for such a detailed guide. This gives me more confidence that my project can still work.
 

FAQ: Ideas on How This Exhibit was Designed?

1. How did you come up with the concept for this exhibit?

The concept for this exhibit was developed through brainstorming sessions and collaboration with a team of designers and experts in the field. We also conducted research on similar exhibits and gathered feedback from potential visitors to ensure the concept would be engaging and informative.

2. What was the inspiration behind the design of this exhibit?

The inspiration for the design of this exhibit came from a variety of sources, including the subject matter, the target audience, and the overall theme of the museum. We also drew inspiration from nature, art, and other exhibits that have successfully engaged and educated audiences.

3. How did you decide on the layout of the exhibit?

The layout of the exhibit was carefully planned to ensure a logical flow of information and an engaging experience for visitors. We considered factors such as the size and shape of the space, the number and type of exhibits, and the desired path for visitors to follow. We also conducted multiple mock-ups and made adjustments based on feedback from our team and test groups.

4. What materials and technologies were used in the design of this exhibit?

The design of this exhibit incorporates a variety of materials and technologies, including interactive displays, multimedia presentations, and physical models. We also used eco-friendly materials and incorporated sustainable design principles into the exhibit.

5. How did you ensure accessibility and inclusivity in the design of this exhibit?

Accessibility and inclusivity were important considerations in the design of this exhibit. We made sure that all interactive displays and information were accessible to visitors with disabilities. We also incorporated diverse perspectives and cultural representations to ensure that the exhibit would be inclusive and relatable to a wide range of audiences.

Back
Top