laser

531 Articles

Projectile Speed Sensor

September 7, 2010 by 16 Comments

[Mike] built a sensor rig to measure projectile speed. The setup uses a tunnel with two sensors in it. Each consists of a laser diode on one side focused on a photodiode in the other. The two are monitored by an op amp and measured by an ATmega128 microcontroller. When the beams are broken the elapsed time between the two events is measured in order to calculate speed. There is a setting to adjust the calibration for a range of speeds, which came in quite handy as [Mike] initially tested the device with rubber bands before moving on to a pellet gun and then a rifle.

It seems like he’s tempting fate by shooting a target just a few inches below his exposed circuitry but his marksmanship prevailed. We’ve seen bullet speed detectors in the past, used just for the delight of seeing how fast the projectile is moving, and also to capture an impact at just the right instant.

Building A Laser Cutter From A Weak Laser

August 26, 2010 by 24 Comments

We covet laser cutters and this diy model with a 1 Watt IR diode may be well within our price range. Most commercially available laser cutters, and some homemade ones, work in the 20-100 Watt ranges, using a CO2 laser. They have more than enough power to cut right through a lot of materials so how can a 1W diode compare? It seems that the weaker laser is still quite powerful right at its focal length, so moving that point along the Z axis will let you burn away a larger depth of material. The test rig seen above uses optical drive components for the three axes and managed to cut a rectangular piece out of the black plastic from a CD case.

This isn’t [Peter’s] first try with CNC lasers. He’s the one that’s be working on an open source selective laser sintering platform.

[Thanks Osgeld and Vesanies]

Another Home-built Laser Projector

August 22, 2010 by 21 Comments

[Jarrod] sent us a link to this home-built laser projector after seeing a different projector that we featured yesterday. This system is fundamentally different. [ChaN], who finished the project several years ago, didn’t use a loudspeaker to move the mirrors, but instead build his own closed-loop Galvanometers. Two of these are controlled by an ATmega64 to produce incredibly clean and accurate vector images. It’s not just the images that are impressive, his hardware is laid-out with skill and forethought that make hiding it in a case a sacrilege.

Vector Plotter With Lasers

August 21, 2010 by 13 Comments

[Hubert] sent in his experiments using HDDs, CDROMs, speakers, and other components to make an XY laser plotter. Those carefully reading will note, its not all three to make one plotter, but rather three plotters each using a separate system. The setups have their advantages and disadvantages, and [Hubert] is sure to point them out; including circuit diagrams and pictures to help you on your own trials.

There is a little difficulty in reading English not so good, but considering we’ve never seen a single-laser vector plotter done before (spirographs come close, and no one wants to wait 85 seconds) it’s still very impressive.

[Thanks TJ]

1W Blue Laser – Remarkably Easy And Dangerous

August 20, 2010 by 92 Comments

[youtube=http://www.youtube.com/watch?v=lE3F7vjYx4U]

We’ve been covering Laser Hacks pretty much since the beginning but it’s surprising to see the niche market that has sprouted up around building powerful handheld modules. [Styropyro] filmed the video above as a tutorial on building a 1W blue laser. The “flashlight” that he starts with includes a heat sink intended for a laser diode. It seems there’s a lot of choices when choosing one of these build kits. A one Watt blue laser diode is press fit into the heat sink and wired in place. The body of the device receives a boost converter to get the batteries up to 1A, and once the assembly is complete the burning begins. It lights candles, matches, and pops balloons; the normal laser demo goodies.

So it’s a pretty easy build. But it’s also easy for someone being careless to damage their eyes. As [Styropyro] mentions in his comments, just looking at the dot created by the laser will damage your sight.

Rapid Furniture Prototyping

July 20, 2010 by 11 Comments

SketchChair is a piece of software that takes the engineer out of engineering furniture. In a child’s-dream-come-true you draw the outlines you’d like to have, add some legs, and the software pops out a design ready to be laser-cut. The finishing touch of adding palm fiber and felt produces what we imagine is a moderately comfortable place to sit. Now the hard part will be convincing your spouse that you should spend the money building an industrial grade laser cutter because of all the money you’ll save on furniture.

We’re still holding out for furniture that is 3d-printed from rock to match our Flintstone’s motif.

Oh, and as always, video after the break.

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