Odds and ends

[Mark]

If I had some of these or metal bars instead of the wire commonly sold, it might be interesting to see what response they would have as or in a ball bearing motor.
https://www.dvidshub.net/image/856856/n ... ring-balls

[Mark]

Another thought comes to mind pertaining to the electrically driven ball bearing motor. It touches on this Trevelyan Rocker article, how the two have some things in common you might say. Imagine a rocking/clocking motor with a make and break electrical contact that repeatedly adds heat to the rocker. Maybe have a bimetal thermometer contact for good measure.

"A bimetallic strip is a strip that consists of two strips of different metals which expand at different rates as they are heated. They are used to convert a temperature change into mechanical displacement. The different expansions force the flat strip to bend one way if heated, and in the opposite direction if cooled below its initial temperature. The metal with the higher coefficient of thermal expansion is on the outer side of the curve when the strip is heated and on the inner side when cooled."

(Clockish)
"The invention of the bimetallic strip is generally credited to John Harrison, an eighteenth-century clockmaker who made it for his third marine chronometer (H3) of 1759 to compensate for temperature-induced changes in the balance spring.[1] Harrison's invention is recognized in the memorial to him in Westminster Abbey, England."
"The earliest surviving bimetallic strip was made by the eighteenth-century clockmaker John Harrison who is generally credited with its invention. He made it for his third marine chronometer (H3) of 1759 to compensate for temperature-induced changes in the balance spring.[5] It should not be confused with the bimetallic mechanism for correcting for thermal expansion in his gridiron pendulum. His earliest examples had two individual metal strips joined by rivets but he also invented the later technique of directly fusing molten brass onto a steel substrate. A strip of this type was fitted to his last timekeeper, H5. Harrison's invention is recognized in the memorial to him in Westminster Abbey, England."
https://en.wikipedia.org/wiki/Bimetallic_strip
https://en.wikipedia.org/wiki/Gridiron_pendulum

Ball Bearing Motor - How to Make/How it Works - He has a link for alternate explanations
https://www.youtube.com/watch?v=DjKhggNJGls

Note on an Electrical Trevelyan Rocker
https://iopscience.iop.org/article/10.1 ... /1/319/pdf

Electric Trevelyan Rocker A Trevelyan Rocker is a heat driven oscillator. The edges of the slot cause the lead to expand each time the pipe tips to the side. The expanding lead pushes the side of the slot away causing the pipe to tip to the other side. This process repeats itself. from The Engineering Magazine DEVOTED TO INDUSTRIAL PROGRESS Volume XI October 1896 NEW YORK The Engineering Magazine Co
Captions are provided by our contributors.
https://www.alamy.com/electric-trevelya ... 47194.html

[Mark]

Some fancy Trevelyan Rocker Apparel
https://collection-lhst.epfl.ch/?action ... ect&id=177

[Mike Everman]

Literally two days ago I did this setup with a bimetallic strip from a thermostat. I did not have the dial to know how much it moves with temperature, so I had to measure it.

[Mark]

I wonder if you could make a track composed of bimetal material and as a hot wheel motor rolled over it, the speed would be amplified instead of just an ordinary metal surface?

Double Jumping Bimetallic Disc from Appliance Thermostat
https://www.youtube.com/watch?v=_gWTheIHwbU
Thermal Bimetal Window System
https://www.youtube.com/watch?v=jpMUiEnrchk
Tidbit
https://www.youtube.com/watch?v=JMADcDS25lU

if you missed this,there're some fun facts where it starts and around the 6 or 7 minute mark too if you can hang in there with yet a second demo and thoughts.
https://www.youtube.com/watch?v=s6Ucek7OqBg&t=180s

[Mark]

Just another device
Bimetallmotor,Bimetal Engine
https://www.youtube.com/watch?v=D0R6lDalwlw

[Mark]

On the Rotation of Hollow Spheres of Metal by Heat (Article from 1858)
https://www.tandfonline.com/doi/abs/10. ... 5908642729

Rotation of Metallic Tubes and Spheres by Electricity
https://www.tandfonline.com/doi/pdf/10. ... 5808642519

Ball Bearing Motor
http://kirkmcd.princeton.edu/examples/motor.pdf

[Mike Everman]

Hmm, I have some hollow 1” bearing balls…

[metiz]

Hmm, I have some hollow 1” bearing balls…

That comes with age

[Mark]

I ordered a few solid aluminum and brass ball bearings to try but they haven't arrived yet. It's you pay your nickel and take your chances. It's been a lot of trial and error finding what metals work with another. There's thermal conductivity, heat capacity, thermal expansion, and things like surface contact area, weight, how the metal was formed, surface texture, and other properties/voodoo beyond my understanding. Materials science 101.

https://www.engineeringtoolbox.com/ther ... d_859.html
https://www.engineeringtoolbox.com/spec ... d_152.html

Of note way back in the 1800's Tyndall remarked Rock Salt performed better than anything if I recall. Compare it's number listed in this chart to any metal.
https://www.engineeringtoolbox.com/line ... -d_95.html

[Mark]

Last night I tried a glossy 3/8 inch drive 3/4 inch long reach 12 point chrome vanadium steel socket which rolled back and forth inside a tri clover piece of three inch diameter sanitary pipe for about 13 minutes or so before stopping. Just another odd thing tried, roller bearing style. ha

https://www.amazon.com/940050-Dr-12Pt-d ... B009W9Z0TQ

[Mark]

Hmm, I have some hollow 1” bearing balls…

What sorts of things are the hollow bearing balls used for or what do you use them for? They sound like something nice to have for special projects.

[Mark]

Hey Mike, I bought this bag of tiny needle bearings and parts of some sort, a ring shaped bearing pictured sleeves over each end. Anyway shopping today from the Amazon overstock thrift store, the whole bag was 25 cents. One side of the center hole is wider, like for the head of a bolt instead of a pin that would fit through the center.

[Mark]

The brass and aluminum spheres arrived today so I gave it a shot not knowing if they would work. Several metal trays didn't sustain so I thought the experiment was going nowhere but this pet bowl finally did. It's just strange how particular each metal is. So far my 30 mm 38 gram aluminum sphere hasn't worked.
A Single Brass Ball Bearing Motor
https://www.youtube.com/watch?v=Se1hlK7twzc

[Mark]

Some experiments but not much else. I guess it's a lot of weight to move unless perfected.

Test of a Two Inch Single Ball Bearing Motor
https://www.youtube.com/watch?v=Fxxp-VkKqsY
Large Ball Bearing Motion from Heat
https://www.youtube.com/watch?v=79Jl0g4Gz5Q