When you are a child, do remote control cars in the shop attract you? Do you feel sad when you can’t own a car and play with it? If the answer is “yes”, why not build your own remote control vehicle—a hovercraft now? You can make a hovercraft as long as you follow our manual. This task was initiated from course Vg101: introduction of Engineering at UM-SJTU Joint Institute. 5 freshmen students formed a team called "Angelnearing" to build a wireless control hovercraft. It will take two people 4 hours to finish the hovercraft.
For more information about our Joint Institute, please refer to http://umji.sjtu.edu.cn
Step 1: Preparing materials
· Blower Knife
· Ducted fan Scotch tape
· Servo Pencil
· Electronic speed controller Compass
· Conversion interface Double-sided foam tape
· Arduino and breadboard shield Screwdriver
· Dupont Line
· Plastic bag
· Insulation foam
· Rigid foam
· Cellphone with Bluetooth
· M3 screws and nuts
Step 2: Programming
Download the controlling program to your Arduino
- Download Arduino software into your PC; the website address is http://arduino.cc/en/Main/Software#toc1
- Connect your Arduino Uno singlechip with your computer. If the LED light on the singlechip isn’t lit, reconnect the singlechip.
- Warning：If your PC has never connected with a Aruduino before, install a plug-in.
- Paste the code into your arduino software. Click upload bottom on the interface. The code is in the appendix.
Step 3: Cutting boards to build main structure
Cut two 25cm*30cm baseboards.
- Draw a 5.8cm*3.3cm rectangle 3cm away from one of the shorter sides of the baseboard.
- Draw another 4.3cm*2.0cm rectangle 2.5cm away from the other shorter side of the same baseboard.
- Cut along the edge of these two rectangles by a knife and remove them.
- Dig four holes around the 4.3cm*2.0cm rectangle (two holes on each side).
- Waring: The size of the holes should be smaller than the size of the nuts.
The figure 2 is the size of each part on Baseboard 1.
- Cut two 18cm*3cm bars from the other baseboard. Cut the corners of the board as 4 4cm*4cm triangles
The figure 4 is the size of each part on Baseboard 2.
Step 4: Cutting foams
- Cut four 4cm*4cm*3cm pieces of rigid foam (Figure1).
- Insulating these 4 pieces of foam
- Cut a 10cm*10cm*5cm cuboid insulating foam. Scoop a column with radius of 3.3cm at the center of the cuboid (Figure 2).
- Warning: Make sure at least one side of the insulatig foam is flat for further use.
Step 5: Installing the servo
- Insert the servo into the 4.3cm*2.0cm hole. Fix the servo with four screws.
Step 6: Building up the structure
- Figure 1: Stick four pieces of plastic foam to the back of the baseboard 1.
- Figure 2: Slice a plastic bag as a plane and then put the baseboard 1 onto the bag.
Figure 3,4: Fold the bag upward and wrap edges of of the baseboard 1 upside. Cut the extra part of the bag. Then glue the bag to the baseboard edges with scotch tape.
Warning: The plastic bag on the side of baseboard must be taut.
- Figure 5: Cut a rectangle from the plastic bag on the bottom of the baseboard 1.
- Figure 6: Stick the baseboard 2 to the four pieces of plastic foam and cover the surface of the baseboard 2 with scotch tape (to reduce the friction).
Step 8: Connecting the circuits
- Stick the white breadboard shield to the Arduino shield (Figure 1).
- Connect the 5V socket on the Arduino shield with a socket on the breadboard shield by Dupont wires. Connect the ground socket on the Arduino shield with a socket on the breadboard (Figure 2).
- Warning: the two chosen sockets on the breadboard can’t be on the same line.
- Attach the blower with the conversion interface.
- Warning: If the blower doesn’t have T-plug, weld the interface with the blower by copper wires.
- With Dupont wires, attach the GCC plug to socket on the bread shield (on the same line with the socket connected with 5V socket on the Arduino shield), GRD plug to another socket on the bread shield (on the same line with the socket connected with ground socket on the Arduino shield), RXD plug to TX socket on the Arduino shield, and TXD plug to RX socket on the Arduino shield.
- Attach the red wire to the 5V socket and the black wire to the ground socket on the breadboard, and the yellow wire to the socket 10 on the Arduino shield PWM side
Step 9: Download the operation app to your cellphone
- Download the operation app to you cellphone from the site: http://pan.baidu.com/s/1gdeiwq3
- Warning: The operation app can be only available on Android system.
Step 10: Installing the ducted fan
- Fix the fixation plate to the servo with the screw (Figure 1. What we see on the plate is the remaining of the foam tape).
- Connect the conversion interface with the battery. When the servo stops moving, cut the power.
- Insert the ducted fan into the piece of insulation foam. Stick the insulation foam onto the fixation plate ( Figure 2).
Connect the ducted fan to the electronic speed controller.
Step 11: Balance test
- Attach the conversion interface with the battery. Open Bluetooth on your cellphone. Connect the cellphone with your hovercraft by the downloaded app.
- Click the “60” (maximum speed) bottom on the app and then the “stop” to reset the electronic speed controller.
- Warning: If the ducted fan rotates in opposed direction, switch any two plugs on the fan.
- Put all the components onto the hovercraft. Arrange the positions of the components to balance the attitude of the hovercraft during operation.
Step 12: Run your hovercraft!
- Now you can operate your hovercraft, and get used to the operation system on the cellphone!
- The method of cutting the second baseboard is not unique. You can try different ways of cutting and find the optimal one that gives you the most stable lift force.
- The turning system is difficult to control, you can also program your own operation system by Arduino software and the website http://appinventor.mit.edu/explore/
Step 13: Appendix
The code for Arduino:
//int speedPinA=6;//lifting pump
myservo1.attach(9);//#1 lifting servo
//myservo2.attach(10);//#2 propel servo
myservo.attach(10); // turning servo
if (BluetoothData=='A') //Set the minimum PWM
if (BluetoothData=='B')//Set the maximum PWM
if (BluetoothData=='C')//appropriate initial speed
if (BluetoothData=='D')// increase throttle
if (BluetoothData=='E')// decrease throttle
if(BluetoothData == 'H')//Reset the servo
if(BluetoothData == '0')// turn right then reset
angle += 20;
if(BluetoothData == '1')// turn left then reset
angle -= 20;
if(BluetoothData == 'I')// turn right
if(BluetoothData == 'J')// turn left