For our midterm projects, we were assigned use all of the skills learned in ENGI 210 so far to create a high fidelity mechanical model from a guidebook that has moving parts. I chose to create the Wonderful Wilmhurst Machine from Building Wooden Machines by Alan & Gill Bridgewater.

The purpose of a Wilmhurst machine is to demonstrate and produce static electricity but, unfortunately, the model in the book is unable to generate static electricity.

The first step I took was to plan how I wanted to create the machine. First, I created a low fidelity prototype to understand ow the machine worked.

Front, side, and top view of the prototype

I used straws to represent the stands, styrofoam balls to represent the half-balls on the base and on the tops of the dowels as well as on the ends of the stanchions, blue cardstock and k’nex wheels for the pulleys, blue foam for the stanchions,  blue and red foam to represent the crank, red and blue foam blocks to represent the base, blue pipe cleaners wrapped around k’nex to represent the center wheel, and white k’nex in the styrofoam balls to represent where the push pins will be located.

Next, to decide on what materials I needed to use, I did a few sketches of each part of the model. I determined what would be laser cut, what would use a dowel, and what could be substituted.

 

The half balls were substituted for a stair stepped pyramid, for which I later decided to use stair stepped gears instead, dowels were used for the stand, the crank handle was done in layers of circles instead of hollowing out a dowel, I decided to make the base thicker by using 4 layers instead of one, and everything else was laser cut as instructed in the book.

I wanted the model be aesthetically pleasing so I decided to add designs to all my pieces with a technology theme so I edited my AI. files from the 2D drawing assignment. I added a gear design to the base but ultimately decided on making it look like a circuit board as well as the center wheel and crank, I made the half ball into several gears the top of the stand into gears, and gave the stanchions a geometric pattern. To make the patterns I installed swatches from vectordiary.com and to make the gears I used a template from opengraphicdesign.com.

   

First two designs vs. the final base design

When I began laser cutting, the first issue I ran into was that the base was cut in sections.

Using the pathfinder tool in Illustrator to merge the shapes together solved this issue.

The gears and crank came out perfectly the first time, except for the smallest gear which was so small that the details did not print.

  

 The first two gears were used and the last was discarded

However, I had issues with the stanchions. The first time, the stanchion completely fell apart after being laser cut, the second attempt broke into a few pieces, the third attempt had holes in it and looked fragile, and the fourth attempt had dark lines across it. I was finally able to cut it correctly on the fifth attempt.

When assembling the pieces I ran into several issues: the base was uneven, the gears and stanchions were too small, the dowels did not fit, and the pieces looked a bit burnt.

  

To make the base even, I printed all of the base layers from the same ai. file instead of having 3 from a blank file and 1 from the patterned file. I also increased the size of the holes in the base to fit the dowels. I first tried 0.50 in holes but they were too big, then 0.45in, 0.49in, 0.47in, and 0.46in. 0.48in was the perfect fit and I didn’t need glue to hold the base together.  I used this size to resize the gears but I decided to use a different gear pattern. I measured the size of the cuts on the sides of the base to redo the stanchions. To solve the burning issue, I changed my cut settings from speed 5 and power 70 to speed 35 and power 50. This also made it much quicker to cut. 

Next I printed the pulleys and began assembling the machine.  To make the pulleys I used two circles with a smaller one in the middle where the string would go. The pulleys were glued using elmer’s glue and super glue was used on the stanchions since they kept falling off during assembly. The pulleys were placed on a dowel on the lower hole of the stanchions. I added the gears to the bottom of the dowels on the base by hammering them down.

Next, The center wheel and upper pulleys were added. These were placed on a dowel. The gears that went on the top of the base dowels were added next by hammering them down.

   

To assemble the crank, I cut out a series of small circles and super glued it to the crank with a dowel to make the handle, and then I put the crank on the front of the machine.

Instead of using string on the pulleys to make the machine moveable, I used rubber bands because they allowed for more movement. At first the machine did not move but I figured out this was because I made the lower pulleys too large. I resized them to make them as small as the top pulleys and now it runs much smoother.

I decided to not use a stain because I did not want to alter the effect achieved by the designs and I also like the natural color of the wood.

Being able to complete this project feels like an accomplishment. Prior to taking this class, I would have never been able to build this machine. Though it was difficult and time intensive, it was worth it for the final result.