How can I Optimize for Scanning

[Digibike]

Hi, 

[edit] foreign language text 

and now in "Tante Google English":

Hi,

I try it in German - maybe someone understands that ...
I have to scan a rather complex part. It is a plastic case for
the headlight, horn and ignition of a NSU Quickly from the 1960s.
The part I have prepared so far and just do not come to a clean scan surface.
You can see it, but it does not do that to me as a consistently 3mm thick shell but either
holey or completely filled. Both unhelpful.

Now to my questions:
A) How many degrees Are the individual scans varied to get a good all-around scan? From this I can deduce the number of required recordings ...
I know, there is this electronic turntable, but 1000 euros are currently a bit too violent. I have built a manual turntable with degree scale. He has to get rich first.
B) Is there anything to note / tricks to get a well-integrated shot / recording from the top, so it will be a good all-round scan afterwards - so a finished model that is 3D printable?
C) Can I support the scanner somehow to get better results? Align the scanner assembly and turntable horizontally with a spirit level or paint the part in 2 colors with matt colors. Think of the inside Matt Red and outside Matt Gray z.b.
Black and silver do not go and shiny surfaces create light reflections that disturb as far as I have observed. White does not work really well either (I took spray chalk paint), because it's very bright, but drops quickly in the transition to the shadow - because the optimal balance contrast is difficult ...
D) Currently no option, as even more expensive as the turntable, but perhaps in the future: Does the option of a 2nd Scan optics actually a significant improvement? Then he picks up the current recording from the left and right of the scan rail and creates a 3D image from it.

I hope you can help me! I'm really in a circle ...

Greetings, Digibike

Can no one help with this questions?

Or can someone give tips on how the scanner is best aligned?

Ich gehe mal davon aus, dass die Leiste mit der Kamera und dem Beamer sowie der Drehteller Horizontal im Wasser sein sollten (Fluchten mit Horizont).

Is there an optimal slope of the bar with the projector and the camera to the turntable? For example Tilted 22 degrees down so that the camera looks 22 degrees down on the object on the turntable or similar?

Thanks for helping!

Greetings, Digibike

[drndadoo · Accepted solution]

Hi Digibike,

I will try to help you with your questions.

A) How many degrees Are the individual scans varied to get a good all-around scan? From this I can deduce the number of required recordings ...

Number of scans that you need to make if you want a good scan depends on the object that you are scanning.

If the object is rich with geometry, you will need fewer scans to complete, if geometry is simple, than you will need more scans. There is no exact number.

B) Is there anything to note / tricks to get a well-integrated shot / recording from the top, so it will be a good all-round scan afterwards - so a finished model that is 3D printable?

When you are making additional scans from the top or bottom, you need to take  overlap into concideration. There should be enough points that softwarae can use for the alignment.

C) Can I support the scanner somehow to get better results? 

For the shiney objects you have to use coating spray. Your calibration and camera exposure should be adjusted to the white color of the spray to get good results. You can recalibrate scanner if needed. 

D) Currently no option, as even more expensive as the turntable, but perhaps in the future: Does the option of a 2nd Scan optics actually a significant improvement? 

Second camera will give you 2 options, to scan bigger area at once or to get more precise scan.

There is no exact number how much precision is better with second cam.

Mit freundlichen Grüßen

drndadoo