Rotating Platform for 3D Scanning

A 3D scanner is a device that allows you to generate the STL file of a part in real life. This system consists of a pivoting base where the part is positioned, then a camera assembled to the system (cellular) takes photos at each angle of rotation, finally these photos are uploaded to a photometry software that generates the STL file. In this instructable, we'll show you step-by-step how we created a rotating plate for 3D scanning purposes.

The plate rotates automatically when an object is placed on it. This is given by a force sensor positioned below the system. This project has been built in the context of a rapid prototyping class, in which 3D printing, laser cutting and Arduino coding techniques were implemented.

The following project inspired our idea: https://hackaday.io/project/168301-arduino-controlled-photogrammetry-3d-scanner

Let's begin!

Tools

• Tape
• Scotch tape

Electronics

• Arduino Uno card (Example Here)
• Force sensor (Example Here)
• Stepper motor 28BYJ-48 (Example Here)
• Motor driver
• 10k Ohm resistance

We used CATIA V5 Software to design the system. The model is composed of a plate, an internal gear with a stator, a pinion and the structure (casing). We took into consideration the space required by the electronics and we added some features to have an easier assembly.

The Arduino code is divided into three parts.

• The first part is used to define all the constants and PIN behaviors in the system.
• The second part is used to initialize the motor, using the library "Stepper.h". We have also included two complete rotations, to ensure the functionality of the system.
• The third part is used to read the value of the sensor, comparing this value with the calibration value "poids minimum". If the analog value read by the sensor is greater than the calibration value, the system turns.

The code file can be found here below, feel free to improve it!!

3D printing

The structure, the internal gear, the pinion and the presionador were 3D printed on a Creality Ender 3. It is important to note that the internal gear is inside a stator, this is the reason why both parts are printed together.

We recommend using the following printer parameters:

• 30% infill (Except for the pinion, we printed it at 100% infill since it is very small)
• PLA (200°C extruder and 60°C bed)
• 4 wall lines
• -0.05m horizontal expansion for the internal gear and the pinion
• 0.28mm Quality

The total filament usage for all parts is about 190g. It took a cumulative 16.5 hours to print all of the parts.

Laser cutting

The plate (plateau) was made of MDF (3mm thickness) by laser cutting. Here below you can find the draft and dxf files.

To do the assembly, the electronic connections are represented in the different schemas in this step. The Force sensor was glued close to the center of the lower face of the structure so that the terminals could be inserted into the lower casing hole. We used tape to put the Arduino in the box, and scotch tape to fix the presionador in the external face under the structure touching in this way the force sensor.

To start the system you only need to connect the Arduino to a 5V source, for example, your PC !!!