Darth Vader: "[The Emperor] is most displeased with your apparent lack of progress."
Moff Jerjerrod: "We shall double our efforts!"
Darth Vader: "I hope so, Commander, for your sake. The Emperor is not as forgiving as I am. "
Stirling Engine Project 2010 
Most recent update January 10, 2010 4:17 PM
Your task is to build a working heat engine from a set of provided plans within a specified time frame. The heat engine should run on candle power. You are encouraged to work with family members or friends -- this can be a family project. Students and families are responsible for acquiring some of the materials necessary to complete the project. If this is a hardship, please talk to your instructor and we can loan tools (tin snips, for instance) or give you materials (candles, aluminum cans, rubber bands, epoxy). We will also have 'work parties' at school with materials available.
This project is aimed at teaching students in a practical, engaging way about the laws of thermodynamics, the workings of a heat engine, and some fundamentals of engineering. Students also gain valuable experience in planning and executing a long-term project with a deadline.
The take-home point, one we can't teach in a lecture or worksheet, is that physics works. If the engine isn't working, there's a physical reason.
Important Links
- Stirling Engine Plans (this is the most important site -- look through it carefully and print it out; note that some folks have had trouble with the .pdf pages not printing to proper scale -- check the scale with a ruler)
- St. Ignatius College Prep YouTube Group for Stirling Engines
- Some helpful hints and tips from your instructors [.pdf, .doc]
- A FAQ addressing the educational merits of this project and student stress [.pdf, .doc]
- Animation of a single-cylinder Stirling engine (with physics explanation!) -- this is similar in principle to what we'll be building
- HowStuffWorks article on Stirling Engines // another Stirling Engine site we found useful
- Biography of Robert Stirling (1790 - 1878) // note the unusual spelling of his name
- More engine designs can be found at QuirkyEngines.com // here's a video of a Stirling engine that runs off the heat generated by a piece of computer equipment!
Safety Precautions
- If you work within the parameters we've defined, this project is no more dangerous than cooking dinner. Still, you must be careful -- just as you can cut yourself slicing carrots or scald yourself heating a pot of water, you can cut yourself on sharp tin or burn somebody (or something) with a candle.
- Protective eyegear is required when cutting metal -- little shards can fly off.
- You must consult with your parents about this project. They should be aware of what you are doing and what tools you are using. This project can be finished with no power tools; any use of power tools must be in the presence of a parent and with their permission and guidance.
- There is the danger of cutting yourself with the cut tin and aluminum; be sure to have a first aid kit handy. Wearing gloves reduces the risk of danger. If you do cut yourself - and it is not a medical emergency - wash the cut, put on first aid cream, and cover the cut with a bandaid.
- Once you are in the testing phase, you will need to use some tea candles. NEVER leave your engine unattended, even for a brief time, if the candle is burning. Be sure you know where a fire extinguisher is. Also, the metal can get quite hot, so don't touch it until it cools down considerably. The room should be well-ventilated.
- Do not use blowtorches, even small ones. Use a tea candle.
- One of the specifications of the project is that you do not use epoxy other than JB Weld for the lower parts of the engine. The reason is that the other epoxies can catch fire or emit fumes. Please be sparing in your use of non-JB Weld epoxies and do not use any epoxy low on the engine.
Rubric
- Students are tasked with making a working engine from scratch. Proof amounts to a clear video of the working (running) engine, along with a photo-heavy blog of construction and testing. (Good resource: blogger.com)
- Grade of A+ (4.0): Short video of working engine delivered by e-mail before 4 PM on the first deadline date.
- Grade of A-/B+ (3.5): Short video of working engine delivered by e-mail before 4 PM on second deadline date.
- Grade of B (3.0): Short video of working engine delivered by e-mail before 4 PM on the third (final) deadline date.
- Grade of C (2.0): All parts completed and assembled, but engine not continuing to run under its own power, by third (final) deadline date.
- Grade of D (1.0): All parts completed; problems with assembly by third (final) deadline date.
- Grade of F (0.0): Some parts still incomplete on third (final) deadline date; or, evidence that student's work is not his or her own.