Mini Thermo Fan

This project was made during a fast prototyping course. It consists of a fan that turns on, when an associated thermal sensor reaches a threshold temperature fixed by the user on an arduino code. The goal is to cool down the space. The higher the temperature gets the faster the fan rotates and It slows down when the temperature decreases.

Supplies

Arduino Uno
Arduino Motor Shield (Link)
DHT22 Temperature-Humidity Sensor (Link)
DC Motor
ON/OFF Switch
9V Battery

3D Printing

There are three components 3d printed:

-The fan it self: a fan with a diameter around 6cm, and a hole that match the gear of the dc motor.

-The 2 seperated supports of the dc motor: their goal is to mainting the motor due to small vibrations and to increase the height of the fan so it doen't touch the primar box.

Downloads

Fan.stl

support_bottom.stl

support_top.stl

Components Testing & Wiring

Use the DHT library to test the DHT22 sensor.

Use the AFMotor library to test the motor operation.

Wire up the electronics components following the diagram.

Arduino Code

The code works as follow: The arduino continuously reads the temperature, and verify whether the threshold temperature "temp0" is reached. Once "temp0" is exceeded the motor starts, and its rotation speed is all the more important the greater the difference between the ambient temperature and "temp0".

Full Code:

Downloads

projet_proty.ino

Casing

We first measured the size of our components, then we deduced the necessary volume for the casing. We chose a basic box as a casing, because it is simple to craft. The box is made of wood and was crafted using a Trotec laser cutting machine.

We dimensioned the box on a website named makercase.com and we generated a dxf file of that box. Moreover, we used Catia V5 to place the holes on our box (connections, on/off switch, access to the thermal sensor...). To do so, we opened the dxf file on the Drawing section of catia, then we copied and paste the sketch on a CatPart file, where we could sketch.

The final substep was to set up laser cutting parameters .

Assembling

We finally assembled the parts forming our box and we stuck the supports of our motor. If the cutting is done correctly, the box's faces will fit together (if it's not the case, you will have to use glue to fix them together...). The result was satisfying. You can see the test we made on the video above.