Optics Laboratory Made From LEGO

16A lot of engineers, scientists, builders, makers, and hackers got their start as children with LEGO. Putting those bricks together, whether following the instructions or not, really brings out the imagination. It’s not surprising that some people grow up and still use LEGO in their projects, like [Steve] who has used LEGO to build an optics lab with a laser beam splitter.

[Steve] started this project by salvaging parts from a broken computer projector. Some of the parts were scorched beyond repair, but he did find some lenses and mirrors and a mystery glass cube. It turns out that this cube is a dichroic prism which is used for combining images from the different LCD screens in the projector, but with the right LEGO bricks it can also be used for splitting a laser beam.

The cube was set on a LEGO rotating piece to demonstrate how it can split the laser at certain angles. LEGO purists might be upset at the Erector set that was snuck into this project, but this was necessary to hold up the laser pointer. This is a great use of these building blocks though, and [Steve] finally has his optics lab that he’s wanted to build for a while. If that doesn’t scratch your LEGO itch, we’ve also featured this LEGO lab which was built to measure the Planck constant.

Solar-Cell Laser Communication System

Forget the soup cans connected by a piece of string. There’s now a way to communicate wirelessly that doesn’t rely on a physical connection… or radio. It’s a communications platform that uses lasers to send data, and it’s done in a way that virtually anyone could build.

This method for sending information isn’t exactly new, but this project is one of the best we’ve seen that makes it doable for the average tinkerer. A standard microphone and audio amplifier are used to send the signals to the transmitter, which is just a typical garden-variety laser that anyone could find for a few dollars. A few LEDs prevent the laser from receiving too much power, and a solar cell at the receiving end decodes the message and outputs it through another amplifier and a speaker.

Of course you will need line-of-sight to get this communications system up and running, but as long as you have that taken care of the sky’s the limit. You can find incredibly powerful lasers lying around if you want to try to increase the communication distance, and there are surprisingly few restrictions on purchasing others that are 1W or higher. You could easily increase the range, but be careful not to set your receiving station (or any animals, plants, buildings, etc) on fire!

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What You See Is What You (Laser) Cut

WYSIWYG editors revolutionized content management systems, will WYSIWYC interfaces do the same for laser cutters? Unlikely, but we still appreciate the concepts shown here. Chalkaat uses computer vision to trace lines drawn in ink with the cutting power of a laser.

At its core, you simply draw on your work piece with a colored marker and the camera system will ensure the laser traces this line exactly. There is even a proof of concept here for different behavior based on different line color, and the technique is not limited to white paper but can also identify and cut printed materials.

This is a spin on [Anirudh’s] first version which used computer vision with a projector to create a virtual interface for a laser cutter. This time around we can think of a few different uses for this. The obvious is the ability for anyone to use a laser cutter by drawing their designs by hand. Imagine introducing grade-school children to this type of technology by having them draw paper puppets and scenery in advance and have it cut in shop class for use in art projects.

A red arrow indicates cut line, but a pink arrow is used for indicating positioning on a work piece. The example shows a design from a cellphone etched next to a positioning marker. But we could see this used to position expensive things (like a Macbook) for etching. We also think the red marker could be used to make slight adjustments to cut pieces by scribing a work piece with the marker and having the laser cut it away.

This concept is a product of [Nitesh Kadyan] and [Anirudh Sharma] at the Fluid Interfaces group at the MIT Media Lab and is something we could see being built into future laser cutter models. What do you think?

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3D Miniature Chess Pieces Made With A Laser Cutter

When you think of laser cutters, you generally don’t think of 3d parts. Well, at least not without using something like glue, nuts and bolts, or tabs and slots to hold multiple parts together. [Steve Kranz] shows you how to make these very tiny 3D chess pieces by making 2 passes at right angles to thick acrylic. The first pass cuts one side’s profile, then the part is rotated 90 degrees and a second pass is cut, giving the part more of a “real” 3D look, rather than something cut out of a flat sheet. If you’re having a hard time imagining how it works, his pictures do a great job of explaining the process. He even added some engraving to give the chess pieces for a selective frosted look. We think it’s a cool idea, and well executed too!

But that got us to thinking (always dangerous) that we’ve seen rotary attachments for laser cutters, but they are mainly for etching cylindrical objects like champagne flutes and beer bottle. What if you added a rotating “3rd” axis to a laser cutter that could hold a block of material and rotate it while being cut? (Much like a traditional 4th Axis on a CNC machine). Would the material also need to be raised and lowered to keep the laser focused? Surely software that is aimed at 3D CNC would be needed, something like Mach3 perhaps. A quick Google search show that there are some industrial machines that more-or-less do 3D laser cutting, but if you, or someone you know of, has attached a 3rd axis to a desktop laser, let us know in the comments, we would love to see it.

(via Adafruit)

Lasersaur that cuts 1/2″ Plywood and 10mm Acrylic (Pew-Pew)

Remember when building your own 3D printer was a big deal? We’re starting to think that building your own laser cutter might be the next hot topic.

Boasting a 16,000 square-foot facility, the Dallas Makerspace is an impressive collaboration of local artists, engineers, makers, and thinkers. Recently they embarked on building a serious laser cutting machine. They chose to go with the an open-hardware design rather than buying an off-the-shelf unit. What they built is based on the Lasersaur plans. (Another popular open-source build is the buildlog.net unit.)

They ended up with a huge 24″ by 48″ cutting bed and with a laser tube rated for 100 watts continuous output. It can cut 1/2″ plywood and 10mm acrylic with ease. The entire machine is built from 20mm Misumi aluminum t-slot extrusions, making more like a giant erector set then a commercial built machine. We hadn’t seen too many of the Lasersaur builds out in the wild, so we thought you might like to see one too.

Now, before you start ordering parts to build your own, you should know that a top of the line build like this will run you about $7-10k. But by comparison if you were to go with something with the same cutting area and power, you’d be looking at something like the “Epilog Fusion 40″ at a whopping $40k. With that said, we expect to see more budget laser cutter builds. Cost can be cut dramatically when you go for a smaller machine, with less cutting area, and less power. With that, you can use less expensive steppers, drivers, and frame. We suspect a little as $700 for a smart shopper could yield a very respectable laser cutter.

If you’re interested in learning more about the Dallas Makerspace, we took a video tour back in early 2014.

Laser Cutter Exhaust Interlock is Silly, Educational, Useful

If there’s one maker space that has an excess of mad scientist type hackers, it has to be LVL1 in Louisville, KY. They sure do a lot of crazy stuff, like this simple device to defeat the laser cutter smoke monster. Nobody got the memo about the “simple” part. Instead they created a functional, educational and aesthetically pleasing element for the hackerspace.

LVL1 has a large format laser cutter. Laser cutters emit nasty smoke. Said smoke needs to be vented outside. To do so, it needs to pass through a scrubber/filter so the neighbouring Pigs don’t complain. So they installed a larger, better filter. The Pigs are happy, until the filter gets clogged and the smoke monster decides to escape. Next they install a pressure switch which disables the laser when the filter gets clogged. Laser cutters have a myriad of safety interlocks, so quite often, it isn’t apparent which one caused it to trip. Hence, the Laser Cutter Enable Module – LCEM.

The simple part was to install an indicator that lights up when the pressure switch is enabled, and off when not. But when it’s off, it isn’t clear if the pressure switch is off, or the indicator has failed. Simple, just install a bi-color LED – Red for off, Green for On. But then what about color blind folks who cannot tell the two colors apart? So, finally, two LED’s with clearly labelled text marking them as Enabled and Disabled.

A simple (this time for real) circuit was finally agreed upon. The SPDT contacts of the pressure switch drive the LED in an optoisolator. Its output drives a DPDT relay via a transistor. One set of contacts light up the two indicator LED’s and the other set of contacts goes to the laser cutter enable contacts. Of course, the optoisolator is totally redundant and over kill too – it’s input LED shares the same power supply as the output transistor! Remember the missing memo?

It was time to assemble the circuit. This is where the mad scientist dudes got really creative. On one half of a piece of acrylic, the schematic diagram was etched using the laser. This ensures n00bs get some education. And the remaining half had the circuit laid out in old-skool wire wrap fashion. Holes were drilled and connections were drawn (using the laser, of course) for the various components. Parts were inserted, and wires were soldered to make the connections. The result is what they call the PCB/Mounting Plate/Educational Schematic/Acrylic thing. Of course, exposed connections and wires are no good. So they made a sandwich consisting of a flat acrylic base, and a cut out frame in the middle to accommodate the wire connections and joints. All of this to light up an indicator. Because.

Thanks [JAC_101] from LVL1 for sending in this tip.

If you want to read more about LVL1 shenanigans, check out this post about their Rocketry group, or this post when Hackaday visited LVL1.

Making Your Own Laser Cut PSU

[Csaba] and his friend bought a 600W switching lab-style power supply unit off eBay a while ago, and after about a year of tangled wires and mess, finally decided to enclose it in a fancy box.

The PSU itself required some modification as it was just a controller and a power board — so they added a dedicated mains transformer, and a buffer capacitor. The housing is made out of 3mm plywood which they designed and laser cut specifically for the PSU — and it looks fantastic.

It includes a cooling fan, a small digital display and a whole bunch of controls for finely tuning your electronics power requirement — take a look at the demonstration video after the break.

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