Moctezuma's Challenge - Aztec Calendar

Ok, I had to put MINI to the test… and went to a local artisan shop and got this Aztec Calendar, it was the best I could find in small size, it’s 12.8 cm in diameter.

As some of you may already know about this, it’s difficult to scan a coin, a medal or I guess anything flat. The preview may look amazing but the scan can’t track a thing… so it’s all red.

I managed to track/scan the calendar if the mini was able to see all the piece, but that means the scanner had to be too far away, and that means not much detail.

Finally I tried and repeated the hack that I used to scan the “Saint Benedic” medal. Y put a lot of rubber bands below and all over the calendar.

Why is this a discussion? because I need to understand how to get rid of noise appearing as dots in some parts, mostly where it’s too deep.

That are overlapped points and lose point , you need to clean it …
I suggest you use Advanced mode and fuse the scan at 0.08mm to get rid of the junk data that overscanned some areas and need to be removed.
It happens with round objects .

You going to have better results with Advanced mode fusing …


I scanned with MINI this weekend a $1 liberty coin , the details was only 7-10 microns ( a human hair) and MINI still picked up despite it it’s maximum accuracy is only 20 microns

I scanned it at 45 degree angle

Fused in Advanced mode at 0.08mm point distance … Standard fusing did not delivered any details .

I used my own 3D scanning liquid with a layer of 3 microns


Yes, I did that, I always use Advanced mode and 0.08, it does a good job, but in this case was not enough. I remembered you told me that overscanned areas may result in noise, but thing is that I had to reduce the speed of the table so RS5 could keep tracking the object. It has much detail.
Also I noticed that reflections can cause reflected geometry, so my guess was that fresnel was giving me some here… and sprayed with zinc oxide. I also increased the speed a bit until the lost-track was minimum. I made a few more discoveries on hard edges and detail if you turn the table CCW and move the scanner to the other side.

MINI don’t perform well if the turntable is too slow ( below 30 sec per one 360 rotation ) objects like that are difficult to scan be mouse the middle part get overscanned too much while flat on the turntable .
Put the medalion on slightly elevated position (1cm) and under it crumbled paper or wrinkled cloth , move the scanner to the left or right side of the medalion and capture full rotation , it will not overscan the middle part . Keep the scanner at 45 degrees to avoid vertical lines in the final scan .

Metal and reflections creates micro noises by scattering the blue laser , so matting it will help …
Zinc oxide will works as well mixed with rubbing alcohol and sprayed with regular spray bottle.

very nice scan! the scanning liquid you mention, is it a commercial one (attblime?) or your own recipe - one you can maybe even share?:sweat_smile:

Yes, I did all that. I think zinc oxide did an amazing job.
I think table speed depends on the model, sometimes it lost track if it’s too fast as well.
Also my rubber bands are doing a good job but I will try crumbled paper or cloth.
Tks for your time, I think zinc oxide will help a LOT and it’s very cheap, I sprayed a shiny metal with it and the scan had no problems to scan it. So I assume it made most of the noise to dissapear.
My scan had ~2.5 million points at the end. And many details in the final print. I will post the pictures tomorrow.

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I was involved of finalizing MINI product so I know most everything about it , thanks to my hard work you have 0.02mm resolution today , and trust me slower rotations below 30 sec per 360 degrees rotation will affect the quality of the scans .
Unless your connection is so slow or your phone or computer that you get less than 10FPS.
Remember you shooting over 10 frame per second. If you losing any tracking , you need to set proper your scanning scenario.

I scanned my last coin on top of a plastic cup … without anything else in the scene and not lost any tracking .

It is like making a face picture , front picture give you one flat 2D face photo , now turn it 3/4 and you get full face dimension as you can see more . The same apply to the Scanner , it will see more tracking features at an angle to an object .

Just tips for you to try out , you doing very nice job already .

Looking forward to see your print .

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Thanks Ivan , it is my pre production 3D scanning liquid for precise scanning of a very small elements including very fine electronics , dental and precision scans . Not conducting liquid at around 3 microns special for MINI . But about that later …:wink:

I know who you are!, lol, and I did take my time to read all I could about the scanner and everything you told other people first. That’s how I stumble upon zinc oxide, that thing is very cheap and does a very good job.

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Yes it is :grin: just stay away from electronics, zinc oxide is conductive , for anything else the best alternative.
I have my big back of it for a very long time , easy to clean with a brush after it dry out not even need water to clean .
Skin friendly as well as it is used as sunscreen.

If you sparkle a quart of a teaspoon into your gym or walking shoes , it will keep them fresh for over 6 months like fresh from the store even an old shoes … it have anti bacterial proportions used already by ancient Egyptians …

I did long time ago a research on zinc oxide and found a lot of great usages beside 3D scanning … :wink:

Yes I can see in your work , you did very well prepared yourself , your results showing that !
We all learning on a daily basis as there is always something new to try out .

Each scanned object requires individual attention and good planning , and if you know well 3D modeling as you do , it will be much easier to handle , as you understand the nature of 3D objects .

Keep up the good work ! Looking forward to see more of your work .

Yes Zinc Oxide it’s incredible!. Did you tried titanium bioxide?

Can someone point me in the right direction for the zinc oxide folks are using here? Is it a spray or powered? I’m finding tons of zinc oxide compounds on Amazon, but not sure which would work best so any advice would be MUCH appreciated!

No , in a form of a spray it is not safe for your lungs and all 3D sprays companies stopped using it , the particles are too small .
Exposure to powder particles can irritate the eyes, nose and throat. since it has been shown to cause lung cancer in animals. a carcinogen may also have the potential for causing reproductive damage in humans.

Don’t Use Zinc oxide in nano form, only cosmetic grade . The nano form powder can penetrate even your skin …

If you really need to use , wear proper mask and glasses while handling the titanium dioxide powder , especially while spraying .

never mind lol, tks for the advice!

You need s non nano zinc oxide , I use this one for years

1 Pound Bag - NON NANO Uncoated - 100% Pure Pharmaceutical Grade

Mix it with rubbing alcohol or any alcohol 75-95%

Until you get slightly milky consistency, something like 2% milk , less is more , you don’t need to make your objects white , just slightly matte , kinds frosting effect what you need.

You can use a simple spray bottle you find at home , or airbrush .
For very big objects you can use even a old Lysol spray bottle for example … shake each time before spraying .

Use a painter brush to clean the object after use , it will works better than water …

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I mixed a very small part of it with denatured alcohol, but you will notice it’s not soluble but it takes some time for the powder to sink, so you have to make the mix in some small container and shake it. I used my airbrush to spray the part.

Thank you VERY MUCH!!! That is quite helpful!

You are a wonderful source!!!


Also now wondering if anyone has tried applying a thin coat of the zinc oxide power using a powder “duster” to dust the object.

Not me… but I guess you will end up with a snow effect.