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Topic: CNC Macine w/ built in 3D Scanner (Read 1 time) previous topic - next topic

melka

I think that by using a pump or a syringue driven by a stepper motor, you can achieve a good filling resolution ^^

vertigoepidemic

Arduino could easily control the stepper motor and the "shots" taken by a camera.

My only qualm is that you would have to flip the item over in order to get a rendering of the bottom side, no?
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vertigoepidemic

Hmm, couple cool ideas at http://en.wikipedia.org/wiki/3d_scanner

A few that I think are interesting are "stereopsis" and "photometric"

With "stereopsis," essentially you get two cameras and take pictures. With image processing, you can determine the distance away a point in the picture is.

http://www.cogs.susx.ac.uk/users/davidy/teachvision/vision5.html

"Photometric" is a  technique in which you take two pictures of an object in different lighting scenarios.

This is turning out to be very interesting! :)
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drone

#8
Sep 02, 2008, 11:39 pm Last Edit: Sep 02, 2008, 11:42 pm by drone Reason: 1
As I understand it, the Roland scanners use a piezo sensor for "acoustic" scanning of a 3d object.  You might be able to replicate this sort of functionality, I found a paper that seems to be related here: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THG-41248CH-B&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=368f0db326418f3a4602a9d1f00218fb

Edit: it appears the Roland scanners use a touch-probe to achieve this.  Considering the low-cost of their units, this might be a viable method for a do-it-yourself-er  (The laser-based units all seem to cost a lot of money =)

!c

vertigoepidemic

I tell ya... Google, Wikipedia and YouTube are the greatest tools ever invented!

Found some cool stuff for 3D scanning. "DAVID-Laserscanner" is a free 3D scanning system.

Couple URLs of interest:
DAVID in action: http://www.youtube.com/watch?v=xK5eYhpBtQc&feature=related
DAVID's website: http://www.david-laserscanner.com/
Paper published about DAVID: http://www.rob.cs.tu-bs.de/content/03-research/03-publications/download/swi_2006_09_konferenz_dagm.pdf (Haven't read it yet)

Basically, you hold print out a calibrating sheet and point a webcam at the scene. Place something in front of the calibrator and shine a laser line over the object then rotate it every 15 degrees or so.

As far as I have seen this process is all hand done, but I don't see why this can not be automated.
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