User:Jeffreycarllloyd/enes100/engine

Link to team page qjb-eng

Problem statement
Construct a Sterling Engine with common materials.

Week0 Activities
-Researched the fundamentals of the Sterling Engine -Confirmed which type of Sterling Engine to concentrate on

-Construction materials list:


 * 2-gallon sized paint cans
 * 1-quart sized paint can
 * 1-1/2" thick piece of UHMW(reduces friction)
 * 2-1/16" x 3" Music wire (connector rods)
 * 1-Coat hanger (crankshaft)
 * 1-Vinyl glove (vacuum seal)
 * 1-Film canister (drive cylinder)
 * 1-7/16" Threaded short pipe nipple w/ nut (hollow anchor for drive cylinder, allows for air flow)
 * 1-3/16" Foam poster board (displacer)
 * RTV Silicone
 * Epoxy glue

-Specialized tool list:


 * Heat gun (for vacuum forming vinyl for drive cylinder)
 * Sheet metal nibbler (cleanly cuts sheet metal without distorting edge)

Assign Task1
-Create a computer model of the design structure of the engine

-Begin layout and construction

Task 1 Assessment

 * Began construction of a paint bucket version.
 * Started Computer Model

Week 1 Activities
I went with a design that utilizes two gallon size paint cans as the displacer cylinder and the support structure. It is a low output version (low rpm, but gives a good idea of the design of a basic Sterling engine.



1st Draft Computer Model (to view must click download in the upper right)

I began construction of the Sterling Engine. I have finished the displacer cylinder, the displacer, and the the drive cylinder. The displacer was constructed with a 3/16 piece of poster board, cut with a 1/8 inch clearance for the radius.

Sterling Engine Week 1 photos

In order to construct the drive cylinder I had to thermal-vacuum the valve (vinyl glove). I used a vacuum attached to a base.It took several attempts due to overheating the vinyl, thus distorting the valve beyond what was acceptable.

| Thermal-vacuum form

I was able to make a solid valve after several attempts.



I used this tutorial and it was very helpful thus far. Paint Can Sterling engine.

Materials list

Task 2 Assignment

 * Complete drive shaft assembly
 * Attempt a test run

Task 2 Assessment

 * Drive shaft was completed
 * Tested system for proper vacuum

Week 2 Activities
Link to Week 2 Photos

Updated Materials list

Started with the Drive Cylinder. Mounted it to the Displacer Cylinder lid by way of a threaded lamb bolt. I used this because of it is hollow and the bottom retaining nut was a low profile that would not interfere with the operation cycle. Before mounting I measured the travel of the Drive diaphragm to ensure there was no interference. As it turned out it was to long, therefore I had shorten it. I used a hacksaw and cut of from the bottom (end with the narrow nut). This in theory will lock the narrow nut in place by the way the cut disfigures the threads.



After mounting the Drive cylinder i tested to ensure that there was sufficient vacuum, or the system would not function properly.

Displacer Cylinder Testing

It performed well without the heat differential, but I did a heat test and it provided vacuum but the displacer did not cycle. Further evaluation will have to be performed as a complete system before I dissection will be rendered.

With the vacuum tested I concentrated on the linkage and crankshaft. My measurement were derived from the formula of displacement stroke is the displacement minus 1/8 dived by two, and the Drive was the displacent dived by 2 then again by 2.



On the crankshaft lobes I installed nylon sleeves to minimized friction. The idea behind this to "crimp" the followers/ linkage as a means to prevent lateral travel of the rods while it maintains the the connecting rods free travel during the cycle.

I started the construction of the crankshaft frame. Again I used the nylon sleeves a bushing/ guide bearing.



To reduce friction I devised a linkage system with re-purposed electric connectors.



Task 3 Assignment

 * Redo the crank shaft ( was not satisfied with the first one)
 * Mount Crankshaft frame
 * Construct and mount the flywheel

Task 3 Assessment

 * Concerns with the crankshaft led me to return to research.

Week 3
revisited research the design of crankshaft. Most tutorials offer little insight. Through discussion it was determine that the stroke of the displacer should 1/8" less the then the displacement dived by two. The question is the stroke of the drive cylinder.

The original tutorial stated that the stroke of the of the drive cylinder should be set at a 1/4" of travel(1/8" offset) and after a mock up it appeared to be insufficient. the total travel of the drive is 1". During discussion in class the it was determined that the 1/4" was insufficient.

During the mock ups the material set aside for the project was deemed to short so I need to acquire more material suitable for the crankshaft.

[http://www.youtube.com/watch?v=O3U4ShL5hkk&feature=player_embedded#! Original Design]

Task 4 Assignment

 * Work out problems with crankshaft

Task 4 Assessment

 * Developed ratio for crankshaft

Week 4
Worked on the team page created the spreadsheet for hours worked

Teams Spreadsheet