Wednesday, 2 September 2009

Laser Scanner

Not strictly RepRap related, but I've been playing with the David Laserscanner software from www.david-laserscanner.com/.

It does seem pretty useful for generating source data. If it's good enough, you can scan an item, tidy up the data a bit, then print it put on your RepRap. The system then becomes a 3-d copier.

So, is it up to the task?

Initial setup:
You need a webcam, a laser line (either a laser level or a laser pointer), and the software.

I used an old webcam (640x480), and a red laser pointer (5mW) from ThinkGeek - but they're pretty readily available.

The software comes with a few different templates - basically a dot pattern you print out. You then attach the pattern to two sides of a 90 degree corner - like the inside of a box, or two card sheets at right-angles.
From laserscanner

You then point the webcam at the box, and 'paint' it with the laser line. The webcam can see the shadow of the line on the object and the background, and can work out the 3-d profile of the object.

To turn a laser pointer into a line, you need to bounce it off a curved surface (I made a line with a shiny metal knife handle), or shine through a glass cylinder. Wandering around Bath, I care across a shop selling christmas decorations - and they had a nice glass raindrop - shape:
From laserscanner

Shining the laser through the glass cylinder produces a nice line:
From laserscanner

I snapped off a short section of the glass and polymorphed it to the front of the laser. I've now got a simple laser line.
Initial playing with the software gives an idea of the result - I think it needs a bit of careful configuration to get the best scans out of it, but the potential is definitely there.
From laserscanner

3 comments:

BodgeIt said...

Yep you beat me to trying that sftware out. I bought a green lazer pointer I have a pound shop lazer level that I took the lense out of to try this out. I Chouse Green as its supposed to be some what safer for the eyes and you can see the beam bought it from Deal Extream.

Did you rotate the object on stepper motor?

Renoir said...

no- no rotation at the moment.

I'd post more, but I've packed everything away for a while, as we're trying to move house :-)

Domonoky said...

We tried the same. But we used motors to move the laser and to turn the object. This gives very nice scans, so you dont need much post-processing to make the object printable. Take a look at www.ifeelbeta.de