Sun-powered Stirling engine with automatic tracking

May 2, 2012 By Leave a Comment

Check out this solar-powered Stirling engine (translated). The build is part of a high school class and they packed in some really nice features. The first is the parabolic mirror which focuses the sun’s rays on the chamber of the engine. The heat is what makes it go, and the video after the breaks shows it doing just that.

But the concept behind the mirror makes for an interesting challenge. The light energy is focused at a narrow point. When the sun moves in the sky that point will no longer be at an efficient position to power the engine. This issue is solved by a pair of stepper motors which can reposition the dish. It’s done automatically by an Arduino Uno which makes readings from four LDR (photoresistors) in that cardboard tube mounted at the top of the dish. If the light intensity is the same for all four, then the tube is pointed at the sun. If not, the motors are tweaked to get the best angle possible.

[Read more…]

Filed Under: green hacks Tagged With: , , , , , ,

Incredible home made miniature engines

April 25, 2012 By Leave a Comment

On the heels of a small stirling engine we featured, an astute Hackaday reader sent in a few awesome builds from HMEM, the home model engine machinist forum.

First up is a fantastic looking stirling engine made entirely from scratch. The build is modeled on a Moriya Hot Air Fan, but instead of making a fan spin around, [IronHorse] put a flywheel on the engine. It also uses propane instead of an alcohol or other liquid fuel lamp for the heat source.

Next up is a pee-wee sized V8 engine by [stevehuckss396]. Unlike the model engines we’re used to, this one runs on gasoline. The engine started out as a 3 x 3 x 5 inch block of aluminum. This thread goes on an amazing 85 (!) pages and makes for great afternoon reading, but here’s a video of the engine in action.

Last is [keith5700]’s amazing 1/4 scale V8. Not only is this [keith]’s first project, he also completed this entire project on manual mills and lathes. There’s an electric starter thrown in there, and the pictures are simply incredible.

Thanks to [Norberto] for sending this one in, and if you’ve got an example of amazing machining skill, send it on it to the tip line.

Filed Under: cnc hacks, Engine Hacks Tagged With: , , ,

Pong, an engine, and Bond theme (oh my!)

April 24, 2012 By Leave a Comment

Hopefully you’re not on a network that blocks YouTube, because we’re sharing videos that show off three different projects. Alas, they don’t give any details about the development process, but we think you’ll like seeing the end results just the same.

First up is a Stirling engine. This one is pretty serious business, with machined parts making up the alcohol-lamp powered engine [Thanks Pete]. This is much more elegant than the tuna can version from last month.

Bust out your Arduino and give theoriginal video game a go. This game of Pong is played on an oscilloscope using two micro-trimpots. To make it happen a pair of MCP4901 DAC chips are feeding the probes.

While you’ve got that friendly blue breakout board out, might as well grab a set of old foppy drives. Here is an eight-channel version of the James Bond theme [via Technabob]. Unlike the sampler from the other week, this one uses the stepper motor noise to create sweet music.

Filed Under: misc hacks Tagged With: , ,