Our task was to create a vehicle to hold 2 eggs safely, and transport them in a 28m long tube using an EDF (fan).
We had a radio controller and receiver to initiate the fan and to also stop it so i=the vehicle stopped before the end of the PVC pipe.
Step 1: Main Body
We used a clear acrylic tube which had an internal diameter 76mm. Length is unimportant.
We measured out 8 holes evenly spaced around the tube. These will be used later to secure the internal fins in place.
We used a slightly damp drill bit to slowly drill the acrylic. (Be careful as it is difficult to drill into acrylic tubes).
After this we drilled another 4 smaller holes at the rear of the acrylic. 2 of these were then threaded for later assembly, The other 2 are for the flaps axle to sit in the middle of the tube to allow the flaps to open.
Step 2: Laser Cutting & 3D Printing
This next step can be difficult without the correct facilities.
Fortunately we had access to laser cutting and 3D printing.
we cut 4 ridges out of wood these were for the internal structure of holding the nose and providing airflow.
The ridges had 2 notches cut into them measured to lineup with the holes in the acrylic tube.
We then cut 2 pieces of wood to create a turntable like piece (shown in the pictures). This would be attached to a servo motor to open the air brake.
2 wooden rings were then cut to fit around the fan, these will hold the fan in the back of the vehicle
The 2 flaps were then 3D printed and placed to pivot around an axle. This resembled a mouth opening and closing. The outlined steps for braking can be excluded if desired. Brakes are not necessary, vehicle can be slowed by cutting power.
Step 3: Electronics Housing
For this step we used a cardboard tube cut in half and hinged at one edge.
We layed a Velcro strip along the inside.
we applied Velcro to the components also; the micro controller,battery and receiver.
The laser cut turntable part was then slid into on end of the closed tube (as shown).
For testing, connect the EDF to the battery and micro controller as well as the throttle port of the receiver.
Step 4: Nose Cone & Eggs
To create the nose cone we used Foam.
The foam was carved into a bullet shape for aerodynamics.
Then we cut the cone in half and hollowed out a compartment big enough for two eggs. This would be filled with cereal to protect the eggs in transit.
This was simply secured with tape when running the vehicle.
Step 5: Assembly
Assembly is easy.
First take the acrylic tube and insert the 4 wooden ridges using the holes and notches to secure them.
Next, insert the electronics housing in the centre of the ridges, this should be secured and held in place by the ridges.
The nose cone is inserted in the same way.
Now at the rear of the tube, insert the fan which should be encased in the wooden rings. To keep the fan in place insert two grub screws in the threaded holes behind the fan (this stops the fan moving backwards).
Attached is an exposed view of the assembly.
Step 6: Testing and Running Your Vehicle
Insert vehicle into the testing tube.
Simply power on your remote controller and turn up the throttle until vehicle accelerates inside pipes.