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[Mark]

Love the clockish one, thanks!

I bought a cheapy 10 dollar swinger from AliExpress to fiddle with. The little spars are too thin to hold heat but I could wire a fat bar or some methodology to it to make something swinging work with heat. Glad you liked the clockish.
Energizing an Aluminum Rocking Toy Base
https://www.youtube.com/watch?v=eF-F32l_Ncs

$160 But it does rock for a half hour. I've had three or four heat driven rockers last over a half too!
https://kyleskinetics.com/shop/p/swinging-kid

[Mike Everman]

Maybe put a AA battery in a rocker, shorted with a high value resistor, so it heats until it dies?
Or there are chem based hand warmers that might work. Sounds like it needs very little differential temp.
Do you have an infrared thermometer to get a feel for the differential right before it stops working? You'd have to calibrate if pointing at reflective surfaces, so it may not work as well as a contact probe of some sort.

If I'm not careful, I may have to add this to experimental back burner #7! Heat engines are so great, but useful ones will hover around some phase change.

This one reminds me a little of the Minto Wheel. I also had a crazy uncle that was trying to patent a wheel that expanded sequentially behind the road contact to push you along. He did not succeed in getting one to work, but much like me, had so much fun with the dream that success ultimately did not matter.

[Mark]

Maybe put a AA battery in a rocker, shorted with a high value resistor, so it heats until it dies?
Or there are chem based hand warmers that might work. Sounds like it needs very little differential temp.
Do you have an infrared thermometer to get a feel for the differential right before it stops working? You'd have to calibrate if pointing at reflective surfaces, so it may not work as well as a contact probe of some sort.

If I'm not careful, I may have to add this to experimental back burner #7! Heat engines are so great, but useful ones will hover around some phase change.

This one reminds me a little of the Minto Wheel. I also had a crazy uncle that was trying to patent a wheel that expanded sequentially behind the road contact to push you along. He did not succeed in getting one to work, but much like me, had so much fun with the dream that success ultimately did not matter.

That's an interesting though your uncle had. The other day I had a ~ 3.5 inch diameter aluminum washer that was hot so I set in on a tri clover reducer, it just sort of rested on the top nearly fitting/sleeving the rim. Later it had cooled and locked itself to the flange of the tri clover reducer rock tight. If there was some way to quickly harness the squeeze force of aluminum in some way that would be fun.
Seems like a fun marketable toy could easily be made using some sort of something.

[Mark]

Maybe put a AA battery in a rocker, shorted with a high value resistor, so it heats until it dies?
Or there are chem based hand warmers that might work. Sounds like it needs very little differential temp.
Do you have an infrared thermometer to get a feel for the differential right before it stops working? You'd have to calibrate if pointing at reflective surfaces, so it may not work as well as a contact probe of some sort.

If I'm not careful, I may have to add this to experimental back burner #7! Heat engines are so great, but useful ones will hover around some phase change.

This one reminds me a little of the Minto Wheel. I also had a crazy uncle that was trying to patent a wheel that expanded sequentially behind the road contact to push you along. He did not succeed in getting one to work, but much like me, had so much fun with the dream that success ultimately did not matter.

That's an interesting thought your uncle had. The other day I had a ~ 3.5 inch diameter aluminum washer that was hot so I set in on a tri clover reducer, it just sort of rested on the top nearly fitting/sleeving the rim. Later it had cooled and locked itself to the flange of the tri clover reducer rock tight. If there was some way to quickly harness the squeeze force of aluminum in some way that would be fun.
Seems like a marketable toy could easily be made using some sort of something.
Something like this or a track of some sort but more gentle an incline roller coaster or a short drop off precipice for the return, or building up steam to finally roll uphill to a drop off return path.

You can't hide the batteries when it's transparent!
https://www.youtube.com/watch?v=r_LG8FDt51U
The one is kind of heavy for motion but movement is interesting if it would have stayed on track. I put one in a large mixing bowl and it ran for a half hour at least speeding up from a slow start.
Wheel Motor Alternating Direction
https://www.youtube.com/watch?v=0e7xBHU7h1c

[Mark]

Interesting ending to the story
Why It Was Almost Impossible to Make the Blue LED
https://www.youtube.com/watch?v=AF8d72mA41M

[Mark]

Just a funny design
Shape Memory Motor Prototype Test
https://www.youtube.com/watch?v=JAbjJY- ... y_VDfgAy7W

A faster one
Very strong Nitinol Engine running on warm water and ice
https://www.youtube.com/watch?v=sscoMtJ ... 7W&index=3

Interesting property of metals hot vs cold
The Metal That Remembers - Nitinol
https://www.youtube.com/watch?v=0xT2du855mQ&t=79s

Tim's Amazing Yi Bell
https://www.youtube.com/watch?v=id-u9ro50TM

"The Yi bell is used to demonstrate the relationship between temperature and oscillation damping."
https://www.a3bs.com/product-manual/U30002_EN.pdf

Tibetan Tingsha Cymbals Versus Temperature
https://www.youtube.com/watch?v=4SOyVX4r3MA

[Mark]

Quite a bit of spring energy as it jumps out of the beaker
Thick nitinol wire tossed in hot water, breaks glass beaker.
https://www.youtube.com/watch?v=MuhwiPzlcCw

[Mark]

"Oh, that's really weird ... Can you hear that?"

How NASA Reinvented the Wheel
https://www.youtube.com/watch?v=vSNtifE0Z2Q&t=900s

[Mark]

"Oh, that's really weird ... Can you hear that?"

How NASA Reinvented the Wheel
https://www.youtube.com/watch?v=vSNtifE0Z2Q&t=900s

[Mark]

Quite a bit of spring energy as it jumps out of the beaker
Thick nitinol wire tossed in hot water, breaks glass beaker.
https://www.youtube.com/watch?v=MuhwiPzlcCw

I just tried the above demo with 1mm thick nitinol wire,1 meter long wound into a ~3/4 inch diameter spring about 2 inches long and dropped into a 250ml beaker of hot water. I must say it was an impressive spring action, like a bomb and suddenly it became a nearly perfectly straight piece of wire some distance away and water all about.
"Unlike most metals, Nitinol contracts in length when heated but will maintain the same absolute volume. Also, its thermal movement is 100 times greater than other metals. A bone staple is one example of nitinol thermal size contraction."

[Mark]

Airborne 03.13.24: We Fly Deltahawk!, Kite Magnetics eTrainer, Pulsejet!
https://www.youtube.com/watch?v=Aoj61D06MGU&t=567s

https://wave-engine.com/

[Mark]

I liked the reversing egg effect, first a vacuum and then pressure which made the egg to change directions.
Egg in the Bottle, Several Variations to Try
https://www.youtube.com/watch?v=dkPRx2Qmjsg

[Mark]

I wonder if a circular tube with intermediately spaced holes could work/sustain?
Bizarre traveling flame discovery
https://www.youtube.com/watch?v=SqhXQUzVMlQ

Viewer comments ..
"You just figured out a phenomenon, that I think is being developed right now in rocket engines. I got a friend in engineering that told me they are working on an engine design with a flame spinning around, gets 30% more efficiency as of now"

"Somehow i accidentally did this a few days ago when i unintentionally lit a jar filled with rubbing alcohol, the flame just went around and around on the lip of the jar and i was super confused by it. Now i stumbled on this video and i have my answer, cool."