Engineering Design Process

In STEM Skills today, we practiced implementing the engineering design process by designing and building a vehicle for carrying an object. This exercise was intended to cultivate familiarity with the 8-step process, which we will follow when designing a 3D printed object.

Engineering design process:

1. Design problem: design a mode of transportation to move something across a table
1. We misinterpreted the problem by assuming that the object would be chosen by the teachers, so we focused on designing a car that could carry items of any size.
2. Research problem:

1. How to use K-nex: spiky pieces are joints, bars are connectors, put rubber tire around circular piece
2. Limiting factors: time, materials, # of wheels
3. Specifications: use only materials in kit, must carry object

3. Imagine:

1. Car-like: 4 wheels, central bar, possibly 2 side bars to provide strength for the car and a carrying mechanism for the object
2. Carrying object:

1. rubber band drag object
2. support structures on car
3. Rubber band strap object

4. Plan (diagram):
   
   
   
   
   
   

   
   
   

   
   
   

   
   
   
   
   
5. Build prototype (before rubber band added): 




6. Test:
1. rolled well with phone and water bottle
2. at first, frame too hollow: needed more support for object
7. Improve: 
1. added horizontal bars to prop up object
2. added a pair of yellow joints on lengthwise bars to serve as a platform
3. added 3 pairs of joints standing vertically on the bars to serve as props. We discovered that this arrangement allowed us to slide the three joints along the bars, expanding the ability of the car to carry differently sized objects
4. while adding joints, we had to replace the 2 lengthwise bars with smaller segments connected by orange connectors
5. tied the rubber band to each of the red prop joints, creating a "safety belt" for the object
8. Redesign
1. After the success with the phone, we tried to stand the water bottle vertically on the car, but the bottle inevitably tipped over when the car stopped. To remedy this, we laid the bottle on its side and strapped it onto the car using the rubber band.