Odds and ends

[Mark]

Here's another one just recently made, I was wondering how many Hz it's cycling at, or if the sound would somehow reveal it? It was weird how when I thought to try using a magnet to hold the jumper down, how unexpectedly fast it seemed to run, how peculiarly it suddenly catches the rhythm when I go to start it.
https://youtu.be/KfbRd5LtIxc

And this one just very simple.
https://youtu.be/ZiBcnxdmY7Q

Here's the video that kind of got me interested in jumpers, it's a good video on how to make one and a fair amount of interesting data in French and English.
https://youtu.be/QYZje3YfuO8

[Mark]

Another jumper that was minimalistic.

Easy Balloon Three Piece Stirling Hot Air Jumper
https://youtu.be/B547cKwERzI

[Mark]

A fast one. At the 1:14 mark it appears stretched and frozen for a few seconds.
Speed Test of a Stirling Engine Hot Air Jumper
https://youtu.be/ciHfynKzFE0

[Mark]

A silicone condiment container jumper or making things with odd things.
https://youtu.be/b1KA3NQcQYg
https://youtu.be/WnteuWwNKAw

[Mark]

Another odd thing to use to make a jumper.
Stirling Hot Air Jumper with Sippy Cup Lid
https://youtu.be/SbBvBssQw8M

[Mark]

This is a toothbrush holder I bought long ago thinking it might be useful for a jam jar jet or something but instead this simple three piece engine made by adding a silicone jar lid and some steel wool.
https://youtu.be/qn9DUPrqUVw

[Mark]

Martini Glass Stirling Hot Air Jumper
https://youtu.be/7UkkXHwxR9Q

And a bit faster.
https://youtu.be/PA0hhiqEhFg

[Mark]

It seemed like there was an outside chance I might have been heating this a little too much. It's a lot of mass slinging up and down being held with two magnets and a stretch press-fit wobbly drill dust catcher bellows. Living on the edge. ha

Pressure Loss on a Stirling Hot Air Jumper
https://youtu.be/WXUVMTi8cZU

Film Developing Tank Engine Parts
https://youtu.be/rBeaZNxOQYc

[Mark]

I saw this engine which is just a can with a glass tube and some steel wool wrapped around the bottom of the tube and the tube attached to a diaphragm. Also a little pan of cold water jackets the top region for cooling. For some reason it brought to mind my snorkelers, for it breathes in and out even though it's an external combustion engine. It's kind of interesting how expansion and contraction here have some commonalities with a jam jar jet snorkeler even though evolutionarily on a different branch. Perhaps it might be possible to make a jam jar jet snorkeler with a flexing up and down snorkel.
Free Piston Hot Air Engine - Torque adjusting
https://youtu.be/-3E8TldOFcU

What I found interesting when experimenting with a steel wool displacer or very loose-fitting piston in a sense, is that in a large quartz test tube over a liter in volume is that if you heat the bottom and have a diaphragm at the opposite end, if you tilt the steel wool so that it slides to the hot end the diaphragm pulls in and likewise when the steel wool is tilted so it slides to the cold end the diaphragm puffs out. It's just kind of interesting to think about.

Rolling-down diaphragm piston vs. Hot Air Engine (Metronome)
https://youtu.be/l572pE3bA4I

The Hot Air Engine that You Never Did Before - tutorial with tin cans and spider
https://youtu.be/A6IB1wwA0_A