Automata Mzmacky 9
In Honors Physical Science grade 9 this year Mrs. McGuire has taught us about automatons. For my project, “The Far Away Spy”, I have two moving parts. One consists of a globe spinning in a circle. The other part has an ufo on a follower moving up and down. As you read, I will explain the process and corrections needed to make to complete my project. The potential energy of the system is the greatest when the handle and axel are not moving. The kinetic happens when we put work into the system; the work comes from turning the handle. When the vertical follower travels upwards the potential energy is increasing, while the kinetic energy is decreasing (conservation of energy). At the final moment when the vertical follower drops down the kinetic energy in that gear is the greatest while the potential is the least. The spinning of the globe is constant, meaning the potential and kinetic energy is constant.
Supplies
-wood planks that vary in thickness
-1/2 inch wooden dowel
-3/8 inch wooden dowels
-model magic clay
-power tools
-wood glue
-hot glue
-rubber band
Original Plan
We were required to have an outline of what our project was going to be about before we started building. This gave a plan and some room to make changes throughout the project build.
Building the Handle
I attached a 4 inch, thin piece of wood to my axel. The wood had to be drilled two times with both 1/2 inch drill bits. This is because my axel and the handle of the gears were 1/2 inch pieces of wood. As a change from my original plan, I added a rubber band. The rubber band was a quick way to prevent the handle from moving while it turned.
Building the Box
The box was made up of cut pieces of lumber. The base was 12 inches long while the sides were 8 inches high. They were attached with wood glue and left to set. The holes are each side are 1/2 inches because of the axel. The top of the box was not glued on until later in the project.
The Rack and Pinion
The assembly of this gear took the most time in the project. The first thing that is needed are two symmetrical circles. One of my circles was drilled with a 1/2 inch bit, while the other was drilled with a 3/8 bit. This is because the axel and follower dowels are different in size. I used hot glue to attach my teeth the the circles, but I recommend using wood glue. To keep the follower dowel from moving everywhere, I glued a piece of wood on top to the follower. While on the bottom of the lid, I glued a piece of wood to the lid itself. After some test runs I found it easier if the teeth were flat to the circle. The teeth also need to be evenly placed, or the gear will get stuck.
The Cam and Follower
With a power saw, I cut the cam out. The uneven cut creates the effect of the ufo moving up then directly back down. The hole is 3/8 of an inch because of the follower dowel being the same measurement. I attached a cut circle onto the bottom the the dowel. Then I hot glued a block of wood on top to the board to keep the dowel in place. The cam was kept in place and secured with hot glue also.
Final Touches
Once the gears were finalized, I wood-glued the lid of the box onto the sides. I left it to dry while making the clay models of an ufo and globe. Once they were warped into their shapes, I decorated them with markers. The blue circle was colored with green to make it look like the earth. The ufo was spotted with little grey creatures on top. The title was added with blue painters tape.