Weekly Updates

Week 1

Figure 1. Rough design of the roller coaster

     The first design sketch for the project. This probably won't be the final design, it was just a rough sketch drawn in 3D Line Rider style.

     The motivation behind this project is roller coasters. What goes into designing one and what would happen if two cars raced each other? The main goal of the project is to build a roller coaster out of Lego blocks and K’Nex pieces. It will be built to have two separate tracks with two separate cars, and the two cars race against each other. The project will be programmed to have a different car win in a random order. 

     The major tasks of the project will be designing the outline of the roller coaster tracks, building the support for the track and programming the Lego Mindstorms to control where the car will go.

     A possible design for the two roller coasters is to have the cars start on the bottom and have the two cars go backwards up very high and let go so the speed of the drop can help it complete the loops and corkscrews. We are still discussing on how we can get the cars to go backwards and how high we should make it. The beginning of this video would gives a better description.

Each team member has a specific task that they must complete. Most task will be completed together. For more information, go to the about us page.

Week 2

Figure 2. The second design of the roller coaster

     The second design for the roller coaster. The first hill will have 2 chains controlled by two different motors so that one of the cars will go faster than the other. The cars will then go down two more hills and then go through the loop. Then a single motor controlling 2 chains at the same speed will pull the cars up another hill, then they will go down, go through the corkscrew, then turn through a cylinder setup, then return to the start to repeat the process. A stopping mechanism still has to be designed for when the cars come back to the start.

Figure 3. Possible car design

     The first design for the roller coaster car (made out of LEGOs). The wheels are inside & underneath the car like on a real roller coaster so that the car won't fall off the track.
     This week we all worked on the design of the roller coaster. We have a 3D model we made on Roller Coaster Tycoon and made what the cars will look like on Lego Design Builder. We also have the 4' by 5' foam board to build the roller coaster on. In order to stay on schedule, we need to finish most of the design next week and start building the roller coaster.

Week 3

     This week, we met and decided what the roller coasters will look like. We are going to have both roller coasters start by going up a hill and drop into a loop. Then they will go their separate ways and go up another hill and they will do their corkscrews. They will both do some helixes and then go back to the beginning. 

Figure 4. Final design for the roller coaster (Top down)

     We also stared building the support for the roller coaster. We have our height for the first hill and the support.

Figure 5. Support for our first drop

Week 4
     We decided to lower the height of the first hills and built the supports for the two lower hills. We were trying to find get the first hill as high as we can so the cars can have enough energy to complete the loops and corkscrews. We decided that the first hill does not need to be that high after we saw our limited supplies, especially the length of the chain that pulls the car up the hill.

Figure 6. The support for the three hills

Week 5

    In lab this week, we started placing tracks on the support and completed the first hill. We still need a longer chain to pull the cars up the first hill, but we decided to continue and start building the rest of the roller coaster.

Figure 7. The first hill for both roller coasters

We placed the chain on one of the hills and we can now get the car up the hill and hopefully down into a loop. We are still building the loop but getting the car up the tallest hill we are building is one of our major task for this project.

Week 6

This week we have the car going into a loop when it goes down the first hill. We also programmed the NXT to start from a cell phone. The phone is a DROID and the app can be installed on there. The app is called NXT Messenger we use that to start our roller coaster. Hopefully by next week we can get the car to go up the second hill and into a series of corkscrews.  

Figure 8. The NXT Messenger App and description

Week 7

     We got more K'Nex roller coaster sets to get more necessary material to finish our project. We met up and connected the chain of the other roller coaster and the second hill of the first one. We now have both cars successfully going up the first hill, completely the loop, and going up the second hill. By next week, we should have made the cork screws for both roller coasters and possibly finish them. Here are two videos showing our roller coaster at two different angles. 

Week 8

     We built the corkscrews and attached them to the end of the roller coasters. We also attached the roller coasters to the board. We tested the roller coasters and the right car can go through the whole thing, but the other car can go through everything except for the last revolution in the corkscrew. We tried switching the cars, and we realized the same thing happened. The car on left roller coaster gets stuck on the last revolution of the corkscrew. We might need to redesign the left corkscrew, but other than that the roller coasters are running great.

Figure 9. Right side of the roller coasters 

Figure 10. Back view of the roller coasters

Figure 11. Front view of the roller coasters

Figure 12. Left side of the roller coasters

Week 9

     Over the weekend, the corkscrew problem is fixed and now both cars can complete the track. We are now doing some minor changes to make both roller coasters run as smooth as possible and have the cars complete the track as smooth as possible. We are trying to build support for the two outer motors because they occasionally shift which causes the car to get stuck up the hill. If we can make the motor stay in place, the roller coaster will run smoother.

Week 10

     This is the final week of our project and it is now time to present it. The roller coaster meets all the requirements and runs with little error. The main challenge is to safely transport it to the lab. The past ten weeks have been stressful, but also fun.

Figure 13. The final product