User:Cdiffendal7527/enes100/BigBlock

Link to project BigBlock team page.

The Problem
We want to create a multi-cylinder Stirling Engine for little to no money at all with the help of a CAD design using free software off the internet. We want the design to be simple but effective and easy for anyone to replicate.

Task1
The goal for week one is to start with a CAD design and then determine the materials needed to create the Stiriling Engine we want.

Compare actual work done to Task1
We have a computer design that isn't complete so I went ahead and built an engine that was close to what the design looks like.

Week1 Narrative
During week one I began building my stirling engine out of the easily found materials we discuss on the team page. I used a tin food can for a compression cylinder and a 90 degree PVC elbow for the power piston's cylinder. I used a piece of styrofoam cut into a circle with aluminum foil wrapped around it to help make a seal. For the power piston I used a part of a rubber glove with cardboard glued on either side to help prevent rips in the rubber when it is flexed. I used welding rod for the crank shaft and connecting rods. I tried to put the crank shaft together I realized that the two connecting rods were located on the same point of the crank. This is when I found out I didn't off set the PVC fitting so the rods could connect to the correct spot on the crank. My next step is to pull the PVC off and relocate it at the correct angle.

Assign Task2
The new task for week two will be to re-position the PVC fitting and once all of that is corrected I will make the crank shaft to fit the modified engine.

Compare actual work done to Task2
This week I decided to start over form scratch and make a new engine since the ruffles in the side of food cans allow air to pass by too easily.

Week2 Narrative
This week I began to make a new stirling engine because the old one didn't work right. I deviated from the original plan of make the engine out of common house hold items because the ones I used were not very effective. I started off with three inch electrical conduit and cut it down to 3 and 3/4 inches tall. then I made my own end cap for one side out of 1/16 inch sheet metal and welded it onto the conduit. After that I used styrofoam and aluminum foil to create a new displacer. Also I used new PVC fittings to make the power piston. Once both pistons were made I used metal rod to make the connecting rods that go to the piston. they are all attached by ring style crimp on wire connectors. to make the top of the compression cylinder I used a tuna can that fit perfectly into the conduit and I epoxied it in place. To make everything for this engine it took about four hours,mainly because I had wait for glue to dry. I put my engine on the stove with the heat on low and did my first test run to see if the engine would work on its own. Unfortunately it didn't work but it began to move a little bit, all i need to do now is to figure out why the action isn' smooth. First attempt of my engine.

Assign Task3
For week three I am going to find out what is holding up the movement on my engine and figure out a way to smooth things out.

Compare actual work done to Task3
Over the last week I pulled the engine apart and found why I believed the engine didn't run smoothly.

Week3 Narrative
I had to deal with the problem of the action in all the moving parts being sticky. Both of the pistons were no moving properly and I had to figure out why. After looking over the engine and spinning the crank shaft with my hands I determined that it (the crank) was the problem. So I disassembled the engine and made a new crank shaft. I started by using a wire hanger because its easy to bend. I made the offset for the displacer about a quarter the height of its full stroke which was about 1.5 inches so i made the offset on the crank about 3/8 of an inch tall. Then I started making the offset for the power piston which has a stroke of only a half inch. I was told by Mr. Foerster that the offset for the power piston should be half of its full stroke so the cranks offset is .25 inches. I then reassembled the engine and spun the crank by hand and the action of all the parts was much smoother than it had ever been.



Week3 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Assign Task4
I plan to make add a some kind of sleeve over the compression cylinder to keep it from having water enter the chamber from ice cubes.

Compare actual work done to Task4
I added a water tight sleeve on to the compression cylinder

Week4 Narrative
I searched for options on how to add a water tight sleeve on my engine and found that hobby shops had small diameter metal tubing that could work just fine. I got a piece of the metal tubing that had a inner diameter of 5/32 inches which would allow a very tight fit around my 3/32 inch thick connecting rod. In order to install it I once again had to disassemble my engine. Then I cut the metal tube down to 2 inches tall which was about a quarter inch taller than the tuna can I had on top of my compression cylinder. I slid the tube over top of my connecting rod and then epoxied it in place and after the epoxy dried it was water tight and it gave enough protection over the cylinder to hold up to 1.5 inches of water from melted ice cubes. Then I found that the supports I made for the crank shaft were not sturdy enough to hold the crank in place while it is spinning. To fix that problem I came up with the idea to have styrofoam cushions to help keep the supports in place. I started by cutting out 4 small cubes of styrofoam about .5x.5x.25 inch cubes. Then using electrical tape I very tightly fastened the cubes on to the supports. I made multiple passes with the tape to make sure the supports weren't going to move.

Week4 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Start Next Project Week0 activities
During this week you will perform the week0 activities of the next project.