I wish someone would design ... (my suggested design & other suggestions)

My mother was hard of hearing. She spent $200 each ear for hearing aids. Then she spent $600 each ear for better model hearing aids. 1985 dollars. I suggested using ordinary plastic kitchen funnels as ear trumpets. No batteries to replace. No squealing when the volume control was set too high. Good frequency response over speech frequencies. My mother was too self-conscious to use funnels. Many people in the world live on $2 per day. They cannot afford hearing aids or the luxury of being self-conscious. There is need for an ear trumpet that is self-supporting on the ear, so the wearer does not have to dedicate a hand to holding the trumpet in place.

Prince Rupert's drops have the shape of raindrops. These days they are made by heating the end of a soft glass rod with a Bunsen burner. When the glass melts, it is allowed to drop into a bucket of cold water from a height of about 4.5 feet. Usually the glass drop shatters when it hits the water. But occasionally the glass hardens, forming a Prince Rupert's drop. Surface tension makes the glass very hard. The head of the drop can withstand being hit with a hammer; a really strong blow will just dent the hammer. But the tail of the drop shatters easily, causing the entire drop to shatter.

So far (about 350 years), the drops have been just a novelty. Each drop has a unique shape. There has been no way to protect the sensitive tail from shattering the entire drop. Digitizing each drop and 3D printing a customized holder that protects the tail, could enable exploitation of the extreme hardness of the head of the drop.

http://en.wikipedia.org/wiki/Prince_Rupert%27s_Drop

Quote:

---

Originally Posted by Daniel Ross

Prince Rupert's drops have the shape of raindrops. These days they are made by heating the end of a soft glass rod with a Bunsen burner. When the glass melts, it is allowed to drop into a bucket of cold water from a height of about 4.5 feet. Usually the glass drop shatters when it hits the water. But occasionally the glass hardens, forming a Prince Rupert's drop. Surface tension makes the glass very hard. The head of the drop can withstand being hit with a hammer; a really strong blow will just dent the hammer. But the tail of the drop shatters easily, causing the entire drop to shatter.

So far (about 350 years), the drops have been just a novelty. Each drop has a unique shape. There has been no way to protect the sensitive tail from shattering the entire drop. Digitizing each drop and 3D printing a customized holder that protects the tail, could enable exploitation of the extreme hardness of the head of the drop.

http://en.wikipedia.org/wiki/Prince_Rupert%27s_Drop

---

Sorry Dan, you have lost me now... :confused:

Quote:

---

Originally Posted by Geoff

Sorry Dan, you have lost me now... :confused:

---

I assume you mean lost sympathy, not lost intellectually. Any further posts will have clear immediate application.

Quote:

---

Originally Posted by Daniel Ross

I assume you mean lost sympathy, not lost intellectually. Any further posts will have clear immediate application.

---

Hi Daniel, I am going to leave the thread. I think now I feel like the one who is copping abuse.

I was simply saying you lost me now, not for poking fun, not for being 'sympathetic' nor intellectually lost. To clear it up, I was just wondering how we got from the hearing aids to the prince ruperts drops. The hearing aid was on track with the theme of the thread in 3D printing advancements and how we can use this technology to better the world..

... . then the ruperts drops, as fascinating as they are, did not connect the dots for me for any of the other topics we have discussed so far in this thread. Is that a bit clearer? if I missed something I apologize.

Anyway, Good luck with your myriad of ideas, hopefully one of them will come to fruition.

Pilot relief valve for vehicles stuck in traffic. Adapt aspects of Air Force design. Wikipedia article does not convey nuance.

Quote:

---

Originally Posted by Daniel Ross

funnels as ear trumpets

---

Design improvement. Around the large end of the funnel, provide screw threads for an optional add-on attachment. The attachment is a hollow cylindrical tube with slots cut around the side, vaguely similar to a gun silencer. The principle is the same as for a shotgun microphone, causing extreme directivity at the cost of some of the funnel's acoustic gain. Compromise directivity vs. loss.

http://en.wikipedia.org/wiki/Microph...ic_microphones

In most of my clothes and luggage that have zippers, the zipper is the first component to fail. There is need for zipper design improvement. The zipper is a mature product. Design improvement may be impossible.

There are 2 sources of zipper failure, one in the slider and one in the teeth.

Slider failure occurs when the crosspiece between the inside and outside parts of the slider, bends. The inside and outside parts of the slider separate slightly. The teeth are not forced together sufficiently to make them interlock completely. A sturdy U-shaped cover over the slider, attached after the rest of the zipper is assembled, and glued to both the inside and outside parts of the slider, would prevent bending and separation of the slider.

Tooth failure occurs when meshed teeth separate spontaneously. Look carefully at the Wikipedia diagram of the teeth. It appears that the teeth do not mesh smoothly. That may be fact, or it may be a deficiency of the diagram. In the mid-20th century there was mathematical derivation of the optimal curve for meshing of gear teeth. I think the derivation also would apply to meshing of zipper teeth. Investigation needed.

http://en.wikipedia.org/wiki/Zipper

3D printer would be used for experimentation and prototyping, maybe on a scaled-up model.

This thread has been moved to off topic as it does not relate to the Makerbot forum.

Quote:

---

Originally Posted by Daniel Ross

In most of my clothes and luggage that have zippers, the zipper is the first component to fail. There is need for zipper design improvement. The zipper is a mature product. Design improvement may be impossible.

There are 2 sources of zipper failure, one in the slider and one in the teeth.

Slider failure occurs when the crosspiece between the inside and outside parts of the slider, bends. The inside and outside parts of the slider separate slightly. The teeth are not forced together sufficiently to make them interlock completely. A sturdy U-shaped cover over the slider, attached after the rest of the zipper is assembled, and glued to both the inside and outside parts of the slider, would prevent bending and separation of the slider.

Tooth failure occurs when meshed teeth separate spontaneously. Look carefully at the Wikipedia diagram of the teeth. It appears that the teeth do not mesh smoothly. That may be fact, or it may be a deficiency of the diagram. In the mid-20th century there was mathematical derivation of the optimal curve for meshing of gear teeth. I think the derivation also would apply to meshing of zipper teeth. Investigation needed.

http://en.wikipedia.org/wiki/Zipper

3D printer would be used for experimentation and prototyping, maybe on a scaled-up model.

---

Or buy items with YKK produced zippers. Lifetime warranty.