As a 16-year-old high school student in the International Baccalaureate program, I was required to complete a ‘personal project’ on a non-academic topic that is of interest to me. I have always enjoyed woodworking and design, so I decided to build a functional wooden bicycle. There was to be no metal used in its construction, only wood and glue. I wanted a project that would be a challenge.
This project came to mind as I was reflecting on many stories my opa, Case Vandersluis, told me about his adventures in Holland during World War II. Opa was roughly the age I am now when he had to build wooden wheels for his bicycle, as rubber was scarce during the war.
I wasn’t sure my wooden bicycle would actually work. I quickly realized the first pieces of the puzzle I needed to figure out were the chain and the sprockets (gears), since the design of all the other components depended on these.
Designing and building a wooden chain that would actually work without breaking proved the greatest challenge. I was mostly concerned that the wooden chain would break. I researched the strength of different types of wood and built jigs to test the stresses that each of the chain’s components would undergo during use. First, I used my weight (150 lbs) to see if the wood could endure this amount of force. Then, my father would stand on the jig.
I calculated that my dad’s weight would be twice the force each chain component would need to withstand. I made the specs high to ensure the chain and sprockets would work even if the wood had imperfections. During testing, I made adjustments to the chain’s components, and once I had it figured out, I realized that completing the project was within my grasp.
When I look back at the completed project, I realize that building the chain caused the most problems and also took the most time (nearly 40%). One of the biggest difficulties was drilling a hole in the spacers—the hollowed-out, cylindrical pieces of wood that keep the two plates apart.
I attached a drill bit to our Shopsmith, which was in the lathe position, and used a chuck to hold the dowel. The job was difficult because the hole had to be drilled exactly in the center of the dowel.
If it was even slightly off-center,the dowel would explode. However, it was only after I had successfully drilled some ten spacers that they began to explode. At first I thought something had loosened and the piece was no longer centered. I readjusted everything, but even after doing so, the pieces continued to explode. I then suspected that the drill bit might be getting dull. I was correct—as soon as I sharpened it, it drilled through nicely again.
Drilling the spacers alone took me pretty much an entire day. It was a labor-intensive job, since each hole had to be drilled separately and there were close to 100 pieces. It didn’t help that I made a small miscalculation and drilled nearly 1.5 times as many pieces as I needed!
Another challenge was drilling the holes into the blocks of rock maple that held the dowels in place for the frame. The difficult part was making sure all the holes were drilled in exactly the right position at the perfect angle to receive the dowels. This became even more difficult because some of the holes had to be drilled with compound angles. I used our Shopsmith and tilted the table to drill the angles accurately. To make sure the angles were correct, I placed a straight metal rod in the chuck and measured them using a simple school protractor. Read more…>>