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accuracy problem

Posted: 27 Aug 2018, 21:15
by erol
Hello friends.

Scans have dimensional accuracy problems (0.2mm-0.4mm).
Part length 55mm

My setup
calibration panel: 60mm (original hp panel)
dual cameras (david sls3)
hp 5.5.0
turntable

calibration values,

camera1 angle: 17.93 ˚ ===> Rms: 0.115
camera2 angle: 17.85 ˚ ===> Rms: 0.178
total: 36 scans

Why the dimensional accuracy is bad and what should I do to fix it.

Re: accuracy problem

Posted: 27 Aug 2018, 23:34
by Micr0
How are you deriving those error numbers/ How are you measuring the accuracy?

Also what is the scan subject? what is it made of?

µ

Re: accuracy problem

Posted: 28 Aug 2018, 21:49
by erol
Thank you Micro for your fast replay.

I made measurements again with my digital calipers tonight and yesterday I was wrong. The part material is silicone. When measuring, the part caused the wrong measurement because it stretched.

I froze the piece deep freeze before the measurement this evening (5 hours).
as a result the accuracy is 0.02mm :)

Re: accuracy problem

Posted: 28 Aug 2018, 22:08
by Micr0
erol wrote: 28 Aug 2018, 21:49 Thank you Micro for your fast replay.

I made measurements again with my digital calipers tonight and yesterday I was wrong. The part material is silicone. When measuring, the part caused the wrong measurement because it stretched.

I froze the piece deep freeze before the measurement this evening (5 hours).
as a result the accuracy is 0.02mm :)
Squishy (very technical term) parts are difficult to get accurate measurements from. I had suspected thus. Glad you solved you problem. :D

Re: accuracy problem

Posted: 29 Aug 2018, 07:07
by mading
Dear Eol,
Do you use the david Acer K132+?

Re: accuracy problem

Posted: 29 Aug 2018, 08:17
by martan
Nice scan!

:)

Re: accuracy problem

Posted: 29 Aug 2018, 19:31
by erol
Thank you.

I have a david sls3 scanner (dual camera and v5.5) and original acer k132 +.

Another scan but I did not check accuracy :D

Re: accuracy problem

Posted: 30 Aug 2018, 14:21
by Micr0
Very nice. You seem to be getting excellent results. Are the surfaces of your scan matching in smoothness to that of your subject?

Re: accuracy problem

Posted: 30 Aug 2018, 15:17
by erol
Thank you Micr0,

The surface smoothness in the scans is generally good and matches the object.