Turntable and object position
I have been struggling with 'bottomless' scanresults ever since I made my first scan.
Re-adjusted and checked things quite a few times, even 3d-printed a stand that nicely fits the fabscan-supplied base-stand so that now my checkerboard is at a 90 degrees angle from the turntable etc. Painted the inside of the fabscan-case black, .... Nothing helped... All scanned objects appeared to be floating above the turntable...
Just to get things working like expected I moved my turntable to the highest possible spot on the steppermotor shaft. Bad scans were the results.
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 soon and let you know in case something comes up.
Note that this is more or less a duplicate of my posts inside the 'Camera position' topic but I wanted to make sure the info would be easier to find by people that are looking for doubts about the position of their turntables and objects. I cannot guarantee this is THE solution, just wanted to let you know that this worked for me!