FabScan – how to build a 3D scanner? A DIY tutorial… VOL 5

In the last episode of our tutorial, we prepared the 3D scanner to work. We uploaded the firmware and created aa flash drive with Ubuntu FabScan. Today we will start, configure and calibrate our device. We will also take the first scan.

Since now we have published four episodes: part I – completing of mechanic components, part II – completing of electronics, part III – assembly, part IV – uploading of the firmware to Arduino UNO and preparing of Ubuntu FabScan system.

Connecting of the 3D scanner:

1. Connect a driver (a blue cable) and a camera to USB ports of your computer. You should see a beam of laser,
2. Connect a driver to electricity,
3. Click on „FabScan”.
4. Click on „Camera” menu and choose an option „UVC Camera (046d:0825)” (it can take some time)
   
5. Choose „Serial Port” menu and pick „ttyACM0”. The laser should twinkle quickly, what means, that it is connected correctly.

Control panel and calibration

1. Choose „Control Panel” from the „File” menu.

2. You should see an image from the camera with a visible line of the laser.

3. If necessary, set definition of the camera by moving of a ring placed close to the lens. The easiest way is to place an item in the middle of the rotary table.
4. If necessary, sharpness of the laser line. You should try to find the finest line. Remember, that it should be vertical.
   
5. Set the laser to point the middle of the rotary table. You can use two screws of the table to do it. Move the laser from the left to the right, to achieve a configuration presented in the picture.

6. Choose an option  „Enable” in „Turnable” section.
7. Click on „Detect laser” to check, if the laser is detected by the software.

8. Click on Fetch Frame.
   The yellow vertical line should point the middle of the table. The table should be placed between the blue and yellow horizontal line. Besides, we can verify the laser line one more time. It is also worth to use  small spirit level to level the table.

9. Place your model on the table and close the window „Control Panel”.

Remark 1. The scanned object should be stuck with double side adhesive type, to make it unmovable, when the table moves.

Remark 2. At the beginning, before you will mark Enable, place the item on the table and move it with your hands, to check how to place it on the table. The laser line should be visible in the camera. It concerns mainly items of irregular geometry. Mostly, the highest element of the item should be placed in the axis of the table.

3D scanning

1. Choose quality from the „Resolution” menu. An optimal solution according to your time and quality is an option „Good”. „Best” takes a lot of time and it is destined for very “strong” computers. Each attempt of scanning in the highest resolution ended up with freezing up of the programme.
2. Click on „Start Scan”
3. After finishing of 3D scanning save a cloud of points to file, by clicking on: „File>Save PointCloud” (unfortunately, it is impossible to export it directly to STL).
   
4. Save it in a suggested place. Choose „PLY(*.ply)” and save your file „skan.ply” (adding of .ply is crucial).
   Close FabScan.

5. Find your file.

Click on „Home”, where you can see your file saved as „skan.ply.ply”.

Click on the file and change it into „skan.ply”.

You can copy this file on any disc, also in case of Windows. If you want to convert it into STL, save also a copy of this file in this place.

Converting your file from PLY into STL:

1. Open „MeshLab”.
   
2. Choose „File>Import Mesh…” and find your file „skan.ply”.
3. Choose „Filters>Normals, Curvatures and Orientation> Compute normals for point sets”.
4. Enter any value, f.e. 100 into „Numbers of neigbors” (it’s just an example value, you can experiment with it, but in case of 1000, the results are satisfactory). Choose „Surf. Pos” from „Get”. In the end confirm it with clicking on „Apply” and wait till it will be done.

5. Choose “Filters>Point Set>Surface Reconstruction: Poisson”. In an opened window of „Octree Depth” enter a value: 7 and in „Solver Divide” enter 8 (these values let you to achieve good results, but it is worth to experiment with them). Confirm it with „Apply” and wait.
   
6. You can use options from the section „A” to see different types of the surface. „B” can be used for shading. If it doesn’t work, use another combinations from the menu „Render”, f.e. „Color>None i Lighting>Double side lighting”.

7. To export your file choose „File>Export Mesh As…” . In opened window of „Files of type” choose „STL File Format (*.stl)”. Enter a name of file with .stl in „File name” f.e. „skan2.stl” and click on „Save”.

A file prepared like this can be 3D printed.

You can example a trial scan made with FabScan here.

It is the last episode of the tutorial. In the future I will maybe publish an epilogue showing a comparison of 3D scans made with FabScan with 3D scans made with commercial 3D scanner Sense from 3D Systems.