Engineering Projects/Engines/Howard Community College/Fall2011/501 BigBlock

Problem Statement

Create a multi-cylinder Stirling Engine out of common house hold materials for little-to-no cost and make it simple in design so it can be replicated by anyone. We want to make something similar to the engine in this video.

Team Members

ARoberts

Cdiffendal

Joon Kim

Summary

The problem that arose in our last attempt at creating a stirling motor was that we tried to work off of an model that wasn't showing much success in use. So we decided to change and create our own working motor. This would better portray our knowledge of how a Stirling Engine actually works. We have decided to base our design from a multi-cycle engine that works in the same way a car engine would work, as portrayed in this video. To the right, you can see model of one of the piston structures that was made in Pro-e Wildfire 5. These pistons will be in a line of four in succession and be attached to a crank shaft at the top. From this, we should be able to receive motion powerful enough turn a wheel and propel itself.

Example of one of the cylinders of our Multi-Cylinder Stirling Engine made in Pro-Engineering Wildfire 5

Poster

Beta stirling animation

stirling engine made from the CAD design

Story

Over the month we worked on this project we all decided that it would be best to build engines separate from one another because it produces more results on techniques that work and techniques that failed. In week one we all gathered building materials and began making our engines. After trying to make engine out of the commons house hold materials seemed to be in effective we started using more commercial building parts like wire conduit and PVC tubing that can be found a any hardware store. After we discussed that the ruffles in the walls of most food cans were making the motion of the styrofoam displacers to hard we made the decision to make the compression cylinder with smooth walls out of the conduit. We also had other failures while working individually that led to good ideas on how to make better parts. For example we one of us tried to make a crank shaft out of welding rod because they thought it would be stronger. In fact the welding rod was tough to bend and both offsets needed for the pistons to function correctly were not bent right. Another group member suggested using a metal coat hanger because it was easy to bend with a pair of pliers and it would be strong enough to keep its shape when the pistons put stress on it. Over the four weeks we worked on this project we weren't able to make an engine that worked on its own, but we were able to find ways to solve problems for future groups attempting to this project that will jump start their work.

Decision List

Our first decision is to have one person create a design on a CAD program and the other two will build the design out of common house hold materials. We decided to make make engines individually instead of as a group. This allowed us to try and fail on our own and come back to class and discuss our problems with each other ultimately producing an engine with the greatest possibility of working.

Material List

Aluminum Can

Welder's rod

PVC piping

Rubber glove/ rubber band

Clothes hanger

Aluminum foil

styrfoam

Software List

Pro-Engineering Wildfire 5.0

Time

Time estimates and actual time consumed measurements helps justify salaries (grades). The only way to gain respect for estimated project time and costs is to practice.

Tutorials

The materials we used can mostly be found around the house. Any kind of aluminum or tin can may be used and other items such as wire hangers, rubber bands and rubber gloves can be found in anyones home. Some other things like the epoxy is found at any hardware store like home depot, or ace. As for putting the materials together it just takes time finding pieces are close in size and finding ways to attach them. One problem we had was finding out how to hold the connecting rods together and attach them to the crank shaft. We found that using ring style crimp on connectors are the best way to attach these pieces because they come in just about any size and are easily found at any hardware store. Most projects consist of making instructions to jump start the next team, shrink the learning of tools and software to the minimum, advice on where to purchase materials, how to assemble, etc. Tutorials modified or created are described here with links.

Next Steps

The next steps to this project will be fine tuning the engine and then reproducing the same engine a few more times and creating a crank shaft the allows the engine to perform a full cycle one after the other.