As I studied to be a technology teacher, one
thing that really impressed me during school visits to exemplary programs was
the way they presented the physical environment. I can recall seeing trains
traversing labs, an airplane used as a flight simulator, a pneumatic tube
transportation system transporting items across a room, and a traffic light used
as a color organ connected to a stereo system. I believe students are attracted
to and stimulated by a lab that features operational models or displays that re
present
the foundations of Technology Education - research, design, creativity,
engineering, and the ability to apply these to create a working system. Programs
that exhibit such displays make a visual, and educational, impact on all
visitors. These models have most likely enabled the teacher to more easily
implement curriculum and motivate students resulting in increased classroom
productivity.
The next best thing to having a nice working system to enhance the physical environment is to design and build one with the students and involve community support. This is exactly what a select group of students did at Parkland High School during the 2001-2002 school year. Three seniors approached me at the beginning of the school year wishing to pursue an independent study in transportation technology. We began searching for a challenging project that would help them utilize their strong math and science skills and foster greater engineering abilities. We finally settled on the concept of a roller coaster. This was partly due to the fact that two small coaster models built by students fulfilling transportation course requirements generated tremendous student interest. The first major roadblock was space. The transportation lab was filled to capacity. However, the fifteen-foot high ceiling was relatively barren. A traditional coaster would not make a good project for mounting to a ceiling. But thanks to the relatively new suspended/inverted coaster designs, this concept was now feasible.
Research
The students began in September with the first phase of the technological method; research. They studied coaster designs, searched for existing models, contacted businesses willing to provide support, and discussed design ideas. By the end of September it was decided that we would model an existing coaster; the “Talon” at nearby Dorney Park. We predicted that producing a coaster located in our own community would help with local business support and become more meaningful for observers that visit the technology lab. Our first goal was to obtain the working blueprints of the actual Talon in order to build the replica to scale. Dorney Park was very helpful in providing us with the resources we requested. We were then able to establish our scale and begin the second phase of the technological method; design.
Design
The first design project was a mounting platform. Although the form of the track would match the actual coaster allowing the train to traverse the course identical to the real ride, the support columns would have to all be reversed. Instead of rising from the ground up, they would drop from the ceiling down. The longest columns on the real coaster would become the shortest columns on the model coaster. The mounting platform would also require an open cavity to allow the lift hill to extend beyond the ceiling height another two feet stopping just before the roof. This was necessary so that the lowest part of the track would remain approximately 8 feet off the ground. The extensive design work indicated that the model would be built to a 1/24 scale. All the materials for the mounting platform were donated by two local lumber yards.
Production
The third step in the technological process is production. A major production challenge was how to fabricate track. Weeks of experimentation with many types of materials resulted in the decision to use PVC plastic joined by a cyanoacrylate adhesive. A coaster track has four main structural parts. The backbone/spine gives the coaster its form. Attached to the spine are hundreds of cross ties which support the two rails that the wheels ride on. And finally the support columns suspend the track into its desired form. We used one-inch extruded square PVC tube to match the spine of the real Talon. Approximately 1,200 cross ties were machined out of .09 PVC sheet using a CNC mill. The rails were formed using 5/16-inch extruded PVC rod. The support columns are constructed using 3/4 -inch PVC pipe. And over 300 column mounts were designed and mass-produced using square and round PVC rod. The production of these two piece swivel mounts required several table saw and drilling operations incorporating many jigs. A local plastic manufacturer donated all PVC plastic.
We began building the model coaster track in sections of approximately 10 linear feet in a small portion of the classroom. Each section was built on the ground upside down from its final mounting orientation on the ceiling. Therefore, the students had to think in reverse during all track layout and construction. A grid was used to plot points from an aerial blueprint. These points were transferred to another grid on a construction platform. Adjustable dowel rod jigs were placed on these points and adjusted to proportional heights as indicated by elevation blueprints. Flexible copper tubing was then used to shape the contour of the backbone and 90-degree copper sheet angles were soldered on to the tube to indicate appropriate bank angles. This resulted in a three-dimensional jig of the track before track sections were formed to shape. Students had to convert metric measurements of the 1/100-scale blueprints to customary measurements fitting our 1/24 scale model.
Several other jigs were used to form 30” sections of track with spine and cross ties attached only. These sections were filled with sand and plugged at each end before being placed in a plastic oven for softening the PVC. Out of the oven the track sections could be formed to the track jig and cooled to retain their shape. The sand prevented distortion of the square tube during bending and twisting. All sand was removed after final curing. With the spine formed, the rails and columns could be constructed. Before removing the completed section and breaking down the jig, points were plotted so that each section would fit together like a puzzle when mounted on the ceiling. The completed track section was painted to match the real Talon and put in storage as the process began again for the next section. A local paint supplier donated all paint.
By March the team
had developed good track construction skills and was well on its way. It was now
time to begin focusing on the engineering of the train. T
his challenge required
the adoption of four new team members. One with advance CAD skills, one with
advanced CNC machining skills, and two with advanced production skills. The four
students were in an engineering course with me and expressed an enthusiastic
interest in our coaster project. The chassis and bogies (a wheel assembly) were
machined from aluminum using the CNC mill. The seats and shoulder harnesses were
cast using a plastic resin. And the bogie covers were vacuum formed from
polycarbonate sheet. The bogies have three degrees of movement and each coach
(one car of the train) incorporates 14 bearings. Each coach was painted to match
the actual Talon. All the aluminum and bearings were donated by local companies.
Testing and Evaluation
As components of our train were coming out of the production process, we could then begin the fourth and fifth steps of the technological method; testing and evaluation. We used our section of test track to evaluate and improve our bearing tolerances, coefficient of friction, structural rigidity, linkages, freedom of movement, etc. By the end of April we were in full-scale production of the train in hopes of finishing before the end of the school year. At the same time we were able to begin erecting the eleven sections of track on the ceiling and begin the design process for the lift hill drive mechanism. All eight coaches of the train, the track, and the lift chain were completed a week before the end of school. After hundreds of hours of work and more than $3000 of donations from local businesses, our model talon roller coaster traversed the track around the room as beautiful as the real thing.
Impact
Parkland High School’s Technology Education department does not have an enrollment problem for its many courses, but it may in the future. The problem will most likely be too many students wanting to take our courses. As the upcoming freshman students toured the high school the last week of school, I lost track of how many amazed students watching the coaster stated “Wow, I’m taking this class next year!” Presentations to the school board and community sponsors resulted in newspaper articles and television coverage for the students and the final product. The seven students who worked on this coaster are extremely proud of the final product. As their teacher, I’m proud of the process these students experienced to achieve the final product. Using the technological method to create a working model to enhance the technology education facility can be rewarding in many ways. I encourage all technology educators to use their talents and the talent of their students to make the learning environment a fun and exciting place. Five members of the student team are graduating seniors. Four will be attending engineering schools this fall. The fifth student, not knowing what career path to choose, has decided to become a technology education teacher as a result of his experiences with this project.