2018-08-15 UPDATE: There is a new, fully revised version of this Scanner, that uses two Nema17 Stepper Motors and a control module. You can find the neccessary files here: https://www.thingiverse.com/thing:3050437
2018-05-01 UPDATE: There is a video of the full workflow and the parts and freeware used on youtube: https://youtu.be/NzJlzrXzJ7k
You can see some of my scans here: https://www.thingiverse.com/3dTM/collections/3d-scans
I have been fascinated with 3D printing for some years. Even though the number of free models and good modeling software is steadily increasing, I needed a high-quality 3D scanner, that allows me to create my own models based on real things for 3D printing. Current scanning devices are either inaccurate or still quite expensive. Good "consumer" devices start at ca. 2000€.
Using the technique photogrammetry (also called: structure from motion, short: sfm), led me to some amazing 3D Scans. For instance: coins, small figurines, jewelry and even working security keys, ...
The only thing needed is a decent camera and some software. Basically you take pictures of an object from as many different angles as possible. Next a software has to analyze those pictures and identify common features, that are visible from different angles. With those features, the camera positions can be calculated and a dense point cloud of the model can be formed. Depending on the software, this process can take up to several hours (or even days) of computing time.
As the quality of the 3D model highly depends on the number and quality of the photos, I decided to build the following 3D scanning device, which automates taking photos.
Basically it is a modified turntable, that has a second rotational degree of freedom. Instead of moving the camera around the object, it is fixed in position and the object can be turned horizontally and vertically. In principle, the pictures could be taken manually with a mobile phone's camera. But I highly recommend using a photographic camera, which allows manual settings for shutter and exposure time, as these (and other) settings have to be controllable. Furthermore, the use of a remote shutter-release allows the process to be fully automated, which is really helpful, when you need to take 200+ photos of one object. All the 3D models presented here have been created using a 10 year old Fujifilm S100FS (which now costs less than 100€) and a refined RR-80 remote shutter-release, that works with many other camera-models as well. The photos have been processed with Agisoft Photoscan Standard (179$), but there are freeware solutions available, that do a similar job.
This device can be used for models of up to 15cm in all directions, but the principle can easily be aplied to larger models.
I will update this model and details on the electronics and workflow soon.
The Model is optimized for two Stepper motor 28BYJ-48 with Stepper motor driver ULN2003.
See the scan process:
And a closeup:
To be printed without support. I used PLA.
You might add a brim and really take care on bed-leveling to prevent warping.
Optimized for a tight fit with the stepper motors and for printing with a 0.4mm nozzle. First layer with 0.1mm and 30mm/s, the rest with ca. 70mm/s.