Conceptual model
Identify the problem:
Each pair of students have to design and build a truss tower that can hold a required weight and can get a reading during testing.
Generate ideas:
- Tower- big as possible.
- Tower- use a rectangular shape.
- Use crossed support beams.
- Include gussets.
- Include lamination.
- Use a roof.
Constraints:
- The Tower can be a minimum of 2" x 2" x 3".
- Maximum of 4" x 4" x 5".
- Can only be made out of balsa wood and glue.
- Materials: Pins, foam board, balsa wood, glue, sandpaper.
Criteria:
- Stability- we wanted it to be able to hold together to get a reading.
- Strength- we wanted it to be able to support the weight to get a reading.
- Support- we added gussets and lamination to keep it from falling apart.
- Complexity- we wanted it to be complex enough for it to hold weight.
- Ability to recreate- we wanted to be able to recreate it if needed.
- Amount of sanding- we wanted it to have smooth edges so it would fid together properly.
Research:
- I searched "Best way to support a building" and learned to build a good foundation and add supports from there to make the outline stronger.
- I also searched "Balsa wood tower" and saw several ways to stabilize our tower and got a few ideas for a frame.
- I discovered through trial and error that the more gussets and lamination you use the better your tower will hold together and the more weight it will hold.
Possible Solutions:
- Idea #1: Create a small rectangular tower, making it taller than it is wide. The tower should use support beams in the shape of an 'x'. Have two of these 'x' support beams on each side, achieving a total of eight. Use gussets whenever two sticks of balsa wood cross to add extra support. Include a roof that provides some lamination for the top beams.
- Idea #2: Create a taller tower that uses two vertical support beams on either side of the tower. The tower should have a rectangular vertical shape, making it taller than it is wide. Have two vertical support beams on each side running from the top of the tower frame to the bottom. There should be 8 support beams in total.
Idea matrix:
Summary:
We went with idea #1 because it was smaller so it would have a smaller chance of falling apart. In addition to it's small size it used gussets to help secure the corners of the balsa beams. This idea uses a roof to help keep the shape of the tower as a rectangle, but also provides lamination on the top beams. The double 'x' support pattern provides extra support on each side. I believe our tower will hold over 100 pounds because it's very stable due to all the supports we've added to the frame and corners. I hope it gets a reading before it breaks due to it's stability.
Mathematical model
We cleaned up our data by eliminating extreme outliers and repeated entries. We also removed towers that did not have any readings. These graphs show that most towers that did not use gussets held more weight than the towers that did use gussets. Using this data I think it would be smarter to not include gussets in our redesign and just use lamination and good corner support beams.
Working Model
Graphical Model
Redesign
Looking at our mathematical model, we decided it was a good idea to leave out gussets for our redesign because it looks like models without gussets held more weight than models with gussets. We were happy with how the rest of our model performed so we won't have any changes to the base.