This article explains how to digitize a surface using a CNC mill, effectively turning it into a 3D scanner.
AndyG writes:
This lesson progresses through the basic steps required for digitizing a part on the Tormach PCNC 770. CNC Digitizing is a process using a tool probe and a CNC mill to reverse engineer physical parts into 3D CAD software models. There are two discrete steps to the process:
Point Cloud Generation. Here, the touch probe is used to record a data set of discrete XYZ points. The number of points collect (density of the point cloud) ultimately determines the fidelity of the model. Mach3, the CNC control software for the PCNC 770, has a digitizing wizard to easily gather coordinate data from the desired part and makes this step relatively straightforward.
Surface Creation. Using CAD software tools, the collected points in the data set are turned into a solid surface. This is sometimes called “skinning”. This can be done with a number of CAD tools available in the market today. In this demo, we use a popular open-source software suite called Blender.
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18 Comments
Definitely an interesting technique... Although the resulting point cloud doesn't seem to be as accurate as a laser scan, I imagine this could be used for reflective objects, while laser-scanned objects cannot be reflective. I wonder if the models represented are limited to heightmaps, or if it can digitize 'caves' in geometry.
What exactly does that mean: *my* PCNC Mill?
Btw: those guys who developed a DYI linelaser scanner a couple of years ago, are still in business, and the free software version (free as in beer) is available as well.
http://www.david-laserscanner.com
Just for the few who haven't got a storeroom full of expensive hitec toys ;)
these things are getting cheaper, although I wouldn't buy one just to do digitization. A cnc conversion of a manual mill like the x3 only costs about 3k or so and can do light production work
or you could use the 3D scanner designed by TBuser on thingiverse. Totally open source (hardware and software) check it out here: http://www.thingiverse.com/thing:9972
An alternative laser-scanner is available here: http://www.intricad.com
These guys also offer an affordable turntable solution.
I saw a demo a few years ago and it's quite impressive.
(and a lot cheaper than buying a CNC machine...)
The Tormach PCNC 770 alone costs $6850. If you do CNC work with it then tooling, fixtures and other miscellaneous items will bring it to around $10k. Still cheaper than a laser scanner, but you can pick up a Microscribe digitizer for a similar price.
Using 2 kinnect cameras would be an awesome way to cheaply scan objects. It´ll set you back about 150$ + some coding skills.
As far as I know that wouldn't be detailed enough. A Kinect generates a IR point pattern for analyzing movements of objects and isn't really intended for high-res object scanning. A controlled (by armature, not arm) laser scan like the one I mentioned can be fairly precise.
you don't even need the coding skills, just visit reconstructme.net for a pretty solid piece of free software for using Kinect for 3d scanning. I'm currently looking into how to get it to scan smallish objects (on the order of inches not feet)
I like how the title says "using YOUR PCNC mill", suggesting that everybody has that. :D
Wait, are you saying you DON'T have one? ;)
I have a CNC but I don't thing soo is the best and fastest way to scan something. And a never thrust this machine enough to put my face or any part of my body under this machine ;-)
Couple months ago I test Photofly ( now know on the name of 123D ) for making 3D model with simple photo from your camera : http://www.123dapp.com/catch#catchApps
The technics dvelopped by Lee Perry-Smith is nice too (with camera too): http://www.ir-ltd.net/infinite-3d-head-scan-released
The point is not to buy a CNC mill to scan something, but that if you already have the hardware (at work) you can use it to scan objects. This method is very precise and supplies accurate measurements (eg. mm). Actually such point cloud generation is used in the industry when highly precise XYZ coordinates are required.
As well as the precision just mentioned, with reflective objects some form of direct contact mapping is mandatory. While not for a lot of the Blender community, for those with the need and resources this is a very useful technique.
Just don't try it for mapping the surface of a jelly.
Well, usually precision matters according to the budget at hand. ;)
Concerning reflective objects: in some cases you may get away with chalk spray to coat the object temporarily with a matte surface... as long as you don't run into trouble with the cleaning afterwards.
Anyway, there showed up quite a few funny and interisting alternatives in the comments. So no matter if we can afford a personal CNC mill or not, the post had its value.
And sometimes I'm watching documentaries about astronauts without having my own space ship.
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iModela is a cheap 3D desktop milling machine.
http://technabob.com/blog/2011/10/10/imodela-3d-milling-machine/
I wonder how hard would be to adapt a probe to it and make it work as a 3D digitizer.
There are others, I particularly fancy the DIY ones.
I realized something, since the only thing it needs is a probe and a CNC the makerbot could do the job too.