3D Scanner : Scanning small objects and recreating them visually as a mesh in a computer

Abstract: The purpose of this project was to construct a 3D scanner capable of scanning smaller objects and visualize them in a computer with satisfying accuracy. The goal was then to generate an STL file able to be 3D printed in an attempt at reverse engineering. Components, materials and tools were provided by KTH to the best of their ability and abudget of 1000 SEK was given to purchase components not available at KTH. The scanner was designed using Solid Edge and utilizes two stepper motors to scan objects. One motor is used to rotate a platform that the object is placed upon and the second stepper motor is used to move an elevator on which a distance sensor is mounted. By keeping track of the elevator’s height in conjunction with the rotation of the object, the distance measured by the sensor can be converted into a point in a Cartesian coordinate system. Several different methods were tested in order to see how results varied. Firstly, the density of scanned points was increased, meaning that the sensor returned values more often as the stepper motor was rotating. Secondly, multiple measurements were made for a single point to determine an average distance and in that way reduce noise and uncertainty. Placing a single laser sensor perpendicular to the object rotating plate proved to be the optimal arrangement in terms of accuracy with the limited budget provided for this project. The scans are very time consuming which makes it important to decide whether to prioritize speed or accuracy.