Then I moved it all the way down until the wooden part of the turntable rests on top of the shaft. Also made sure that the laserbeam reaches the front of the turntable and goes right over its center. In order to get the vertical green crosshair to hit the center of the turntable too I added 2 very thin washers to the frontmost standoffs of the ledring-pcb and gave it another try: Almost great results! In any case the best results I ever had! Will go play with the scanner again tomorrow and let you know in case something comes up.

I wonder if maybe my turntable has been fitted to the steppermotor on a too high or too low position(?)...

Would it be OK to use a few washers between the wall of the fabscancase and the ledring printed circuitboard?

Sure.

By the way: My scans already look very nice. I am just missing the bottom 1 or 2 cm's. All of my scanned objects appear to be floating above the turntable.

Have you checked the origin point in the config file, it's described in the documentation.

No matter how much I do my best to have my settings for calibration as perfect as can be (like position of the checkerboard paper and more) the vertical green line never gets positioned over the center of the turntable. Would it be OK to use a few washers between the wall of the fabscancase and the ledring printed circuitboard?

By the way: My scans already look very nice. I am just missing the bottom 1 or 2 cm's. All of my scanned objects appear to be floating above the turntable.

sorry but i think the crosshair is misunderstood. The important part is that the vertical line hits the center of the turntable. The horizontal line does not matter at all. I think i have to remove it in the next release. It only marks the horizontal center of the image. For the horizontal alignment it is more important to measure the origin point from the table to the top of the first square line on the calibration sheet (like it is described in the docs).

The camera should be aligned in a way that you can see the table at the bottom of the image and as much of the object as possible. And of course vertical center alignment as described above.

In the following video you can see how my cam is aligned. ( This video is older. The UI can differ from the current one.)

https://www.youtube.com/watch?v=OFSEnqRDmIE

- Mario

Can't do any better than this: see attached pic (unless I completely misunderstand?)

A picture of the actual calibration crosshair would tell more than words, I guess. Looking forward to it

the holes in the case are aligned in a way that the cam should exactly match the center of the table. One thing i realised in the last two years is that not all lenses are glued perfectly onto the pcb, this is generally regarded to the v2 module. Have a closer look to your camera module. Sometimes it helps to press the "lens module" gently into the right direction. I will try to add this as soon as possible to the documentation.

- Mario

The calibration log file looks Ok and so does the default.config.json file with the calibration values. I include them here !

{
"folders": {
"www": "/usr/share/fabscanpi/",
"scans": "/home/pi/scans/"
},
"laser": {
"numbers": 1
},
"scanner_type": "laserscanner",
"calibration": {
"weight_matrix": [],
"dist_camera_matrix": [],
"pattern": {
"square_size": 11,
"rows": 6,
"columns": 8,
"origin_distance": 37.2
},
"camera_matrix": [
,
,

],
"distortion_vector": ,
"laser_planes": [
{
"deviation": 0.05261286110996645,
"distance": 88.15394578052423,
"normal":
}
],
"platform_translation": ,
"platform_rotation": [
,
,

]
},
"keep_raw_images": "True",
"meshlab": {
"path": "/usr/bin/"
},
"process_numbers": 4,
"turntable": {
"steps": 6400,
"radius": 70
},
"camera": {
"rotate": "True",
"type": "PICAM",
"vflip": "False",
"preview_resolution": {
"width": 800,
"height": 600
},
"hflip": "True",
"resolution": {
"width": 1640,
"height": 1232
}
},
"discoverable": "True",
"serial": {
"plattform_type": "fabscanpi",
"baudrate": 57600,
"autoflash": "True",
"port": "/dev/ttyAMA0"
},
"texture_illumination": 40
}

I only get uncoherent scan results.

See pics of  vertical aligned laser going through center of turntable, spring-adjustable cam-module from standard predrilled holes position so that vertical green crosshair line is cutting laser line in center of turntable, horizontal green line projected towards back plate, calibration using 3d printed calibration stand and the cal-board and waited until I got the message 'calibration finished'.

I also tried to point the camera more downward, to make the crosshair cover the line where the bottom plate is touching the back plate, but then only 2.5 lines of calibration squares are visible and the lower half of the cam image shows the empty bottom zone in front of the turntable: no positive result either.

I even tried a 3rd camera positioning so that the crosshair is in the middle of the white center square on the cal board and recalibrated.

Still lousy scan result afterwards.