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DAVID-Laserscanner

Posted by Nil Einne 
DAVID-Laserscanner
January 12, 2009 01:58AM
Just came across this [www.david-laserscanner.com] in a discussion about the Real-View in another forum.

A sorta DIY 3D laser scanner. You do need your own camera and laser but the software is free for personal use albeit only outputting low res models. Unfortunately Windows only (and obviously not open source).

Looking at the scans they do seem rather decent [www.david-laserscanner.com] [www.david-laserscanner.com] [www.david-laserscanner.com] although it sounds like this is with fancish hardware, experienced operators, a lot of manual tweaking and not with the free version.

Also see there are some other stuff although most of them have very expensive software [www.david-laserscanner.com]

Edited 2 time(s). Last edit at 01/12/2009 02:00AM by Nil Einne.
VDX
Re: DAVID-Laserscanner
January 12, 2009 02:42AM
Hi Nil,

i tried 'david' with a line-laser and a video-webcam - it works, but the quality is highly dependant of the webcam and the ambient light.

When i'll get a highres USB-camera then i'll try anew with a green laserpointer and a line-filter or better an old DIA-beamer and the 'inverted' option, where a thin wire in a frame is projekted over the object.

I think the shadow of a string in the beamer is more accurate than the line-laser which has nearly 2mm width and didn't have the same illumination over the length ...

Viktor
sid
Re: DAVID-Laserscanner
January 12, 2009 06:44AM
Well Viktor,
high quality webcam YES, High resolution No winking smiley
The best results so far came from a b/w vga camera unfortunately that one is around 180 Euros afair.

iirc, it's important to have no image enhancer build in, or at least deactivated.

I found that it's quite hard to brush the part manually with the laserline,
also it's quite annoying since most parts I tried are either too glossy or too dark.
so I quit trying.

btw, the linelaser module they pictured on their website is around 10 Euros in almost every hardwarestore.
didn't measured it's line width, but it's not bad I'd say.

'sid
VDX
Re: DAVID-Laserscanner
January 12, 2009 07:13AM
Hi Sid,

a friend has a b/w-camera with a 3 megapixel CMOS-sensor and a highspeed USB-port, so this could maybe be better than my video- or vga-cams.

Another problem for me are the small sizes of my objects - i want to scan parts with only 2cm size and 0,5mm accuracy, here a laserline with 1mm width is much to coarse sad smiley

For your glossy/dark-problem: - paint the object with a diffuse colour - maybe water-soluble, so you can remove it afterwards.

And for waving the laserline: - try with your reprap or a slow motorized oszillator ...

Viktor

Edited 1 time(s). Last edit at 01/12/2009 07:15AM by Viktor.
sid
Re: DAVID-Laserscanner
January 12, 2009 07:49AM
Well, paint my 100Euro mouse and than dip it in water to remove the paint ...
let me think grinning smiley

Most parts I like to have scanned are not paintable for various reasons,
so that is no option in most cases.

I scanned some putto with very ugly results and large holes in the resulting cloud, although I scanned 8 different angles the best I could.
Okay, putti are hard to scan because of numerous undercuts, but that was the only white'ish non glossy object I had laying around (sitting that is winking smiley)

scanning small parts is almost impossible using a shadowline Viktor.

To have a sharp lineshadow you need to have the pointiest lightsource you can find, regarding the aperture of the camera the thread will have to be too far away to draw a line smaller than 1mm I guess.
Even the backlight of some tft (which is in fact a very nice lightsource to use for photography for example) draws diffuse shadows. sharp enough for galanty shows, but not sufficient for this task I guess.
Nevertheless, give it a try, I wish you luck.

Using a beamer sounds like a good idea, but remember they're made to make sharp images on a FLAT surface... winking smiley

'sid
VDX
Re: DAVID-Laserscanner
January 12, 2009 08:03AM
Hi Sid,

... i'm tinkering around with the idea to use fibercoupled lasers as light-source - then i'll have a 'spot-source' of 100 microns in red/5mW or 60 microns in NIR/1000mW (but here i should remove any IR-filters on the camera-chip).

With inserting my green laserpointer in a glas-fibre i'll have a green spot with 125 microns and something like 0,3 mW.

With a selfmade collimator of 40mm diameter i'll have a 'beamer' that could project a 0,3mm wire as a shadow of maybe 0,5mm i hope ...

Viktor
Re: DAVID-Laserscanner
January 12, 2009 09:45AM
Hi RepRaps

browsing 10 min through RepRaps >>>> wow.

It easily should be possible to use DAVID within the RepRap hardware.

Seems I
Re: DAVID-Laserscanner
January 12, 2009 11:47AM
Its possible to use it, but I think there are much better alternatives on the market that are sometimes free, sometimes not...

Try to look at this site: [www.simple3d.com]

I also found this: [www.muellerr.ch] Maybe something for reprap machines?

But if you want to be cheap, then I would recommend doing this: Take lots of pictures from the same angle, on a rotating frame. Maybe even put a cross on the platform. Then you open google Sketchup, and create points on the pictures you took. Its also something you can do.
Re: DAVID-Laserscanner
January 12, 2009 12:27PM
Hi again:
(now registered, but brandnew so please pardon)

Just some notes on DAVID:

- Since version 2.0 the scanning step result of DAVID can be saved only at a camres of 320x240 in the free version (every pixel hitting the object gives one vertex). So to get a higher resoluted mesh you

Edited 3 time(s). Last edit at 01/12/2009 12:56PM by MagWeb.
Re: DAVID-Laserscanner
October 12, 2010 06:39AM
The owner of following blogsite offers FREE 3D laser scanning services with some terms and conditions.
www.free3dscans.blogspot.com
VDX
Re: DAVID-Laserscanner
September 12, 2012 11:31PM
... someone working with David and Structured-Light scanning?

Purchased for cheap an Infocus X2 DLP-beamer (with broken bulb) and am planning using it with a laser as light source and modified optics ...


Viktor
VDX
Re: DAVID-Laserscanner
September 27, 2012 12:05AM
... made some successfull experiments with replacing the lamp in a DLP-beamer by laserdiodes, what's some more work to do, as the optics have to be heavy modified or completely removed ...

But could test with 'normal' SL-scanning with a Acer-DLP-beamer that came with shipping damage, but was still working after removin all the shattered mirror-pieces.

Here the first 'flying' setup with a (too heavy modified) high-res B/W-camera out from a dental scanner:





... and here the result - 4 scans, aligned automatically:





Next will be some practising with David and modifying another DLP-beamer with a UV-laserdiode for UV-3D-printing ...


Viktor
Attachments:
open | download - SL-Aufbau.jpg (44 KB)
open | download - 4x-scan1.jpg (44.3 KB)
Re: DAVID-Laserscanner
September 28, 2012 04:04AM
That last result looks pretty great, actually. I assume it'd be possible to scan from other angles and merge them as well to fill the remaining holes?
VDX
Re: DAVID-Laserscanner
September 28, 2012 04:32AM
... yes, most 'perfect' 3D-scans are fusions of some ten segments - here is a good sample: [www.david-laserscanner.com]

Every colour is a separate scan, that is aligned and fused to an average point-cloud.

I'm testing with some other concepts and optical modifications, so don't await such qualities from me in the next days ... but this should be the quality you can expect with normal/common SL-scanning ...


For better controlling the angular positions I'm using a pan/tilt-disc, as common for macro-stereo-microscopy use ...

Edited 1 time(s). Last edit at 09/28/2012 05:12AM by VDX.

Viktor
VDX
Re: DAVID-Laserscanner
September 28, 2012 01:33PM
... here are some images of my setup for Tilt-Pan-Height-adjusting the parts so I can scan from all angles:

- horizontal:





- tilted:





- PT-table separated:




Viktor
Attachments:
open | download - PanTilt-Gerade.jpg (217.6 KB)
open | download - PanTilt-Gekippt.jpg (220.3 KB)
open | download - PanTilt-Teile.jpg (244.3 KB)
VDX
Re: DAVID-Laserscanner
October 02, 2012 05:21AM
... some other David-laserscanner users here?


Viktor
Re: DAVID-Laserscanner
October 02, 2012 06:37AM
This is very much on my to do list. I'm trying to wait until the holidays to see if they run a promotional price again. On the other hand, I have a couple minor projects I need to model parts for that don't lend themselves to measuring with calipers.

Your results are inspiring. Compared to RepRap, is it more or less difficult to get good results ?
VDX
Re: DAVID-Laserscanner
October 02, 2012 06:54AM
... with a DLP-beamer it's really easy!

Attached are some images of my second scan - made 8 scans from different angles, removed backgroud-points, auto-aligned, fusioned ...

With a laser-line this wasn't so easy or accurate ...

Edited 1 time(s). Last edit at 10/02/2012 06:55AM by VDX.

Viktor
Attachments:
open | download - Maske-Aufbau.jpg (280.9 KB)
open | download - Maske-8xAusgerichtet.jpg (398.8 KB)
open | download - Maske-Fusion.jpg (275.3 KB)
Re: DAVID-Laserscanner
October 03, 2012 11:52AM
Hmmm. I'd better plan for a projector too then. I'll see if I can do without first, of course...
VDX
Re: DAVID-Laserscanner
November 12, 2012 12:40AM
... I've tested with reducing the image size for smaller objects and higher accuracy.

Without a reducing lens the closest distance is 650mm and the smallest image size is 250x190mm:







With different lenses I received different setups - the smallest usefull for normal camera-scanning give a closest distance of 50mm and smallest image size of 20x15mm.

But here I have to reduce the intensity of the light drastically to avoid overpowering the camera:






With my high-DOF microscope cams the smallest image sizes are around 0.8x0.6mm and maybe 1mm DOF - could be really interesting to test, if the beamer image can be reduced to a corresponding ratio and low enough intensity to SL-3D-scan with microscopic parts ...


Viktor
Attachments:
open | download - Normal-D=650mm_B=250x190mm.jpg (24 KB)
open | download - Reduced-D=50mm_B=20x15mm.jpg (21.3 KB)
VDX
Re: DAVID-Laserscanner
November 14, 2012 07:16AM
... made a test for timing/homogenity with the 'only_red'-modified Casio-beamer and a 10cm tall A&O-figure.

- setup:





- result - the figure is 100mm high:




The finish could be better with optimized timing parameters or remeshing the scans, but already usefull for 'normal' parts winking smiley


Viktor
Attachments:
open | download - Miraculix-setup.jpg (202.6 KB)
open | download - Miraculix-fused.jpg (158.9 KB)
VDX
Re: DAVID-Laserscanner
November 28, 2012 07:09AM
... are there others interested in more informations about modifying and using cheap/spare DLP-beamers for 3D-scanning or 3D-printing?

I'm regularly updating the specific threads in other forums - but 'synchronizing' this projects over 4 forums isn't so funny ... so will post this here too only if there's enough interest in this ...


Viktor
Re: DAVID-Laserscanner
November 28, 2012 12:51PM
How about a link to the other forum thread, with a brief summary of the post? It'll probably load faster for us, and it's less work for you.
VDX
Re: DAVID-Laserscanner
November 28, 2012 02:11PM
... you have to register/login in the other forums to view the attached images, and two of the external forums are in German too, so not really helpfull eye rolling smiley

But here's the link to the German RepRap-sub-forum for 3D-scanning with some more or different infos: [forums.reprap.org]


Viktor
VDX
Re: DAVID-Laserscanner
December 05, 2012 03:02AM
... sometimes I'm getting 'orders' to repair broken parts by scanning the remnants and constructing the missing geometries ...

Here a porcelain sea-gull missing one wing while scanning:





... the aligned scans:





... 'recreating' the missing wing by mirroring the mesh:





... and the fused result:





Next step is to mill a replacement for this one and/or some complete rescaled sea-gulls from PU-foam (light-weight) for a mobile ...


Viktor
Re: DAVID-Laserscanner
December 18, 2012 11:40AM
Hi,

I tinkered around with a David-Laserscanner and came up with two nice pojects:


Overview: [youtu.be]

Automatic Turntable: [www.thingiverse.com]

David-Laserscanner: [www.thingiverse.com]

Best,
Bernhard
VDX
Re: DAVID-Laserscanner
December 18, 2012 12:32PM
Hi Bernhard,

I'm thinking to rebuild my old dental-scanner from the Isel-software and drivers to use with David and eventually replace the line-laser by a SL-beamer:




Another possibility is to let this one as is for small (around 20x20x20mm) high-accuracy scans ... and assemble a new one from the spare parts of the second scanner ...


Viktor
Attachments:
open | download - i3DScan.jpg (437.6 KB)
Re: DAVID-Laserscanner
January 03, 2013 11:11AM
Here's our setup, we used David SLS software with a Del M110 DLP Projector and a Point Grey machine vision camera.

[www.flickr.com]

The funny thing is that it's basically a MendelMax with the top chopped off and a few optics. We control the stepper motors with the RAMPS/Mega/Pololu stack (a bit overkill) and we position the object using the TrinityLabs monorail and GT2 pulleys and belts.

[www.flickr.com]

We took an off-the-shelf window lift motor (mass-produced and cheap worm gearbox), hacked off the DC motor and attached a stepper motor using an aluminum motor coupler and a 3D printed adapter. This give us enough torque to rotate very heavy, unbalanced objects with ease.

[www.flickr.com]

Here are some results. They're good, but the scanner is very expensive. We're trying to determine ways to cut costs so that we can sell these scanners on Kickstarter, fully-assembled under $3,000.

Can you guys help us by giving your input on this survey? It's greatly appreciated. https://docs.google.com/a/3dcreationsllc.com/spreadsheet/viewform?formkey=dEZXV0dvTUYxUktLdkZIaTBqY1JaWFE6MQ
Re: DAVID-Laserscanner
January 04, 2013 02:38AM
You might take a look at the 3DRACS software!


Bob Morrison
W├Ârth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse
Re: DAVID-Laserscanner
January 04, 2013 08:09AM
Whoa that's cool stuff, thanks for the suggestion Bob! Is it the same thing as David-Laserscanner without mesh registration? Well I'll be finding out shortly, thanks again!
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