Hi! We are AnTiProcrastination, a group of students from University of Michigan -- Shanghai Jiao Tong University Joint Institute (see Logo. in Figure 1) Our campus, (Figure 2; cited from www.ngeschool.org) located in Min Hang District, might be an interesting place to visit if you are in Shanghai.
This instructable is created as a part of our project in the course Introduction to Engineering. We were invited to make a hovercraft and take part in a competition in the course. The competition includes two parts: time trail and tournament. In time trail, time of finishing the lap will be measured so that the top 4 team will be divided into different branches in tournament. In the tournament, teams will compete two by two until we have a champion. Top teams in the time trial and tournament will have bonus in their grade.
We also have a few regulations for the competition:
Lifting Height: <2cm (To avoid mechanism like a helicopter.)
Maximum Mass: 800g
Maximum Size: 30cm*30cm*30cm
Voltage: Maximum two batteries (each Voltage≤12V)
Motor specifications: <12V
Remote Control: Mandatory
Step 1: Design the Hovercraft
The first thing to do when making something is to design. For a hovercraft, you need to design both the physical part and the electronic part.
Figure 1 shows the electronic diagram of our hovercraft. The battery to provide power to the whole system; the Arduino board, which is the brain of the circuit, control the system with a programmed code; the electronic receiver receives infrared from the PS2 game handle.
Figure 2 shows the concept diagram for physical part of the hovercraft. Figure 3 shows the specific size of the largest board in the hovercraft. The hovercraft is designed via CAD so that we could view 3D pictures before we actually make them.
Step 2: Prepare Materials and Tools
When choosing the materials, we chose ones that are as light as possible to eliminate the weight of the hovercraft. Here is a list of what we used for the hovercraft for your reference. We tried as much as we can to provide a price list but some of these are found in the tool box, so we do not know exactly how much they cost.
(1 RMB = 0.16118 USD) (Ref: http://www.exchange-rates.org)
Thing we used for the body:
10 RMB Polyfoam
12 RMB Wooden Board
9.8 RMB PVC Board (Actually what needed was light yet strong board, so any kind would be fine. )
2.95 RMB Tent Cloth
53.1 RMB Screws and Pillers
8 RMB L-shaped bracket
1.3 RMB Wire
Things we used for the electronic part:
42 RMB Arduino Uno
40 RMB Fan (for lifting)
30*2=60 RMB Brush Motor(370) *2 (for propulsion)
55*2=110RMB Electronic Speed Controller (for Brush Motor)
270 RMB Battery (11.1V 2200mAh) & Charger
46.8 RMB PS2 Game Handle & Receiver
20 RMB Dupont Wire
Silicon Wire (for higher current)
Insulated Rubber Tape
19.5 RMB Glue Gun (This would be handy when assembling)
1.8 RMB Matte Paper
Multimeter (for debugging the circuit)
Swiss Army Knife (We strongly recommend you to use strong knives, because we ruined a few scissors)
Total 700 RMB
Step 3: Basic Construction
First, cut the poly-foam, the PVC board and the wooden board into the shape designed. (See first four figures). They forms the basic construction of the hovercraft.
Next, cover the poly-foam with tent cloth so that it can reduce kinetic friction between the ground and the hovercraft. (See Figure 4 and 5) We used glue gun to stick them together
Then, assemble them using screws and pillars (See Figure 6 and 7. Figure 6 is taken from below the hovercraft).
* Note: The black square you see on the PVC board is actually Velcro tape for fixing the battery. In this way, we can take the battery down easily when we charge it.
Step 4: The Electronic Part
First, decide how you will arrange your electronic components. Make sure that mass is evenly distributed on the hovercraft. Measure the distance so that you can calculate the length of wires.
Next, connect the circuit according the circuit diagram. Remember to measure the current with multiplier, so that you use silicon wire for higher current.
Then, fix the electronic component onto the hovercraft. Fix the fan onto the PVC board using screws (See Figure 1 and 2). Fix two brush motors on the wooden board (See Figure 1 and 5. We used poly-foam to help fixing the brush motors.) Fix speed controller of each motor below the wooden board (See Figure 5) Fix the receiver on the wooden board and the battery in front of the fan(See Figure 6)
Step 5: Programming and Testing
Now you have to hovercraft with a PS2 game handle to control.
Program an Arduino code for you to remote-control the hovercraft. Test it and modify your program accordingly.
Here is what we did:
Circle: Go forward
Square: Get ready
Triangle: Speed up
Left: Turn left
Right: Turn right
*Note: For tuning left, make the right brush motor rotate faster than the left one. Analogously, for turning right, make the left one run faster.
**Note: You might want to have different lifting height (speed at which the fan runs) for different surface on which the hovercraft is running.
Step 6: Done. Have Fun!
Have a look at our racing video! It moves fluently.
Our result in the time trail was 27sec, which was fairly fast compared to other group. Unfortunately, we were eliminated in the first round in the tournament because our hovercraft stuck on to the obstacles. Nevertheless, we had great fun and learned a lot when making this hovercraft. We Hope that you gain something through reading this instructable, as well. If you have problem, feel free to contact us.