Scanned size is 1.33 times larger with the Mini

I scanned a small object which is 12mm in thickness, but all the scanned results are about 16mm.
16/12=1.33333
I tried to scan another 50x50mm box several times, the results are 67x67mm.
67/50=1.34


(These are measured in blender and fusion 360, in obj and stl format)

It seems all the scans are scaled up.
Will the calibration program fix this issue? I’ve not tried it yet.

Hi! That’s weird. Which software (version) do you scan with?

It’s is impossible , calibration do not fix any issues like that .
Please check well your program that. you use and the proper scale at import , as that is the issues here.

One was scanned with previous version, others are version 4.2.0.20021209b
I also update the firmware for the last scan.
image

I checked blender and Fusion 360, they don’t have scale setting while importing. And in blender I use the default unit, Fusion 360 is in mm.
Opened the model with meshmixer, it still showed 67mm for my 50mm box.

Just checked the ‘fuse’ file in Blender.
Still the same result.

If you will export to .OBJ or .STL file, I will load it into my mechanical CAD software to see how it is interpreted, but I am only expecting confirmation.

Thanks for your help, here is the OBJ file.

I have no better idea for this, so I’ll still try to calibration the device first once I got back home.

Edit : @Dabinn
Indeed one side is 66.4mm and other 67mm
I find this scan is poor in quality , the surface is so grainy it will give you false number .

You should have a smooth scan with MINI not like that , please reduce the fusion pitch point to 0.05mm
increase the denoiser to 4 , mesh level 5.9

and you can re calibrate if you still get grainy surface like that , and if you scan please put it on something higher and not direct on the flat plate as it can change dimensions and for precision do not close the holes .

If the surface is plastic and reflective plastic use 3D spray , reflection from plastic will cause noises

Before Calibration make 3 tests first, the lowest are your best score .
Add some light to the calibration board for faster calibration and better results . Don’t calibrate in darkness

@Dabinn
I find the differences too great to be a scanner error , unless it is something going on with the hardware.
Please re-calibrate the MINI and rescan the object again to confirm .

I checked the last software and firmware , the scanned objects has the proper size after scanning .

Update:
I ran the accuracy test, and got the result of 8.6771 !


After fighting with the calibration program, the result is 0.0591.

Run a quick test, did not scan well, but the size is more accurate.

@PUTV Thanks for your infomation, I’ll keep testing to see if I could improve the grainy surface.

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Hi @Dabinn , wow that is insane , I don’t recall I ever saw this test value before to the level that it affect object size … that’s abnormal.

Please make more tests with other objects or with the bust to make sure it is operating proper and the surface is smoother …you should not have grain effect at this scale at all with MINI .
And definitely not with calibration results of 0.0591

If you do have grain effect on the scanned bust , I would be concerned about the quality of the hardware in your unit .

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I let Revo Scan contorl the auto turntable, it seems the feature lost track a little bit in each of the 3 turn.
Now I use manual contorl and scan the box by only 1 turn, the surface is more smooth. But I am not sure if this kind smooth was enough or not.

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It is already better , make sure the object distance is between 100 to 200 mm from the scanner for best accuracy , having object beyond that distance will result in noisy surfaces and the accuracy will be off.

Maybe you just make a scan test with the bust and show the result in the Revo Scan after meshing . For best evaluation , keep the object at 100mm/10cm from the scanner . One 360 rotation scan is enough not need to capture the whole figure .

Got it!
I have to go to bed, I’ll try more scan tomorrow.
Thank you !

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Ok take your time !
Good night !

@Dabinn here for reference how the surface should look like

@PUTV Here is the scan. Is it OK? It seems smooth but is not much detail.
Scan: 1 360 rotation.
Fuse: Point Pitch:0.05mm
Mesh: Quality: 5.9, Denoise:4, Fill Holes: No

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Yes it looks the way it should look at that settings .
If you fuse it at 0.02mm you get just sharper edges, the bust in general don’t have too much details .
The detail level of the bust is around 0.1mm .

My bust is not the same as yours , since I used my first beta bust when testing the prototype so they looks kinder different.

I just want to make sure that nothing distorting the surface.

Remember when using MINI the best accuracy is at 10 to 20 cm distance anything after the distance can create noises while scanning especially if the surface is slightly reflective like plastic .
MINI after all is for scanning mini objects .

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