Showing posts with label Stirling engines. Show all posts
Showing posts with label Stirling engines. Show all posts

Wednesday, May 2, 2018

Air Engines

Air  Engines (Stirling Engines) have been around a very long time. Robert Stirling built his famous engine way back in 1816. Since then many people have built many different variations on the initial idea.

Air engines require a heat source and a method of giving up the heat in the medium (cooling). No explosive gas mixtures are required such as in the IC engine. Because of this the concept has always had great appeal.

The low power outputs have always held back the idea of the air engine especially in the face of the tremendous power achieved with the oil guzzling IC engines. However in the last 50 years or so, there has been a resurgence of interest in this technology. The ability to run clean is a draw no doubt, in this carbon adverse age. As early as the turn of the 19th century, hot air engines were built that ran on the concentrated rays of the sun. And of course most model builders are familiar with the model that runs on the heat from a cup of coffee.

If you have always wanted to build one or are just interested in the tech., here is a great book written by T. Finkelstein and A.J. Organ in 2001. The subject is well covered from Stirling's development, through the 18 and 1900's, to the modern post-revival. If your interested this is good stuff.

To download "Air Engines" go to my Books - Free Downloads page. # 55 - 4 MB - pdf

So a little update on our delayed spring. I can't remember the last time we still had winter snow on the ground on May 2, it's been a while. Before I did the aggressive landscaping, about half of the lane way had land sitting higher than the surface of the lane way, on both sides. This resulted in the lane way remaining soft for a long time, during spring melt, (my old Cavalier sank to the axles one year). After terracing the north side of the lane way, I dug a drainage ditch between the terrace and the lane way, and cut away the south side of the lane way to a good slope. I haven't had a problem since. I was away for a while, but it looks like the lane way drains and dries as quickly as the snow melts.

Saturday, January 13, 2018

1951 Popular Science Annual Part 3

So here is another posting of old Popular Science projects. Before we go there, here is a small primer on hot air engines (Stirling Engines to some). Engines like the Rider engine pictured in cross-section below were popular near the end of the 19th century. They were safe and easy to run, but proved to be very inefficient, being quite large for small power output. With the advent of gas and diesel power they quickly moved to the back shelf becoming a project for hobbyists to reproduce and try to improve upon.

As illustrated in the second image, improvements have come a long way, smaller size and better cooling and regenerating of the gas in a closed system, achieve greater efficiency. The most advanced units are being used for special applications, like NASA's space program. I have pictures of them somewhere.

 So I went there because the first project is a light hot air engine that will do a steady 400 rpm by simply burning a few scraps of wood from the shop. It is made from mostly light tin containers and other metal scraps from around the shop. As the article says tin snips and a soldering iron are your main tools. This is a nice project for the hobbyist and beginning model maker.

For more advanced projects Dave Gingery built and wrote a few books on different engine types. Heres a picture of his Stirling Cycle Engine manual.

The next project is a nice hand grinder (like the Dremel) one-tool shop. This is ideal for the hobbyist with a small shop or an apartment dweller with a small closet or spare room shop who builds models or other small projects. It will perform many operations without the noise, flying dust and expense.

Every drill press should come with the next project pre-installed. A foot feed for a drill press is very handy for many operations, freeing up both hands for the work being done. Mortising on the drill press comes to mind.

Cheers All