What You See Is What You (Laser) Cut

June 28, 2015 by Mike Szczys 19 Comments

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

June 14, 2015 by George Graves 6 Comments

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)

June 4, 2015 by George Graves 54 Comments

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

June 3, 2015 by Anool Mahidharia 20 Comments

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

May 27, 2015 by James Hobson 26 Comments

[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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Cutting SMT Stencils With A Laser

April 3, 2015 by James Hobson 22 Comments

Prototyping your own PCBs? At a loss for how to apply your SMT electronics? Well — do you have access to a laser? [Felix] shows us a definitive way to use a laser cutter to engrave SMT stencils with ease.

The real trick here is to engrave — not to cut. Typically if you’re using enough power to cut straight through the plastic, you’re going to get melting and burning of the edges — which won’t work well for a SMT stencil. So what [Felix] found is to engrave at approximately 20-30W @ 400-450mm/s. He’s using Mylar as the material.

The results are pretty awesome — but if you’re without a laser, he also has an excellent tutorial on DIY metal SMT stencils by chemically etching soda can metal!

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Robot Arm Wields Laser, Cares Not For Your Safety

April 1, 2015 by Rich Bremer 44 Comments

Here at Hackaday we’ve covered a bunch of DIY laser diode projects. And for good reason, they are just cool. We’ve seen people add lasers to their 3D printers, stick one in a milling machine, use a highly modified scanner and even build a simple XY gantry specifically for the task. To say the least there is definitely a wide range of methods for moving around a laser but we’ve never seen anything like what [Sp4rky] sent in to us. He and his friends outfitted an old educational robot arm with a laser.

The robot arm is a 5 axis Armdroid 5100 picked up from eBay for a couple hundred dollars. It didn’t come with a controller but all of the stepper drivers were housed in the base of the arm. After a little tinkering around with the inputs the team was able to get the arm to move by sending serial commands from a PC, through an Arduino Mega which then sends the appropriate signals to the uni-polar stepper drivers. That was the easy part of the build.

The hard part was getting the arm to hold the laser at a consistent angle and height above the table. Inverse Kinematics to the rescue! Since the desired position of the laser, as well as the length of the arm segments is known, mathematical formulas can be derived to determine the necessary arm segment and joint positions while moving the laser around. The process flow starts out with an image in Inkscape, g-code is then generated with this plugin, then sent to the Arduino running a modified version of GRBL that has the inverse kinematic formulas. The Arduino directly controls the stepper drivers and the robotic arm moves. The Arduino also controls 3 constant-current laser drivers made from LM317 regulators. Three laser drivers, why?

[Sp4rky] got his laser diode modules out of surplus medical equipment and, unfortunately, the rated optical wattage was quite low. Since he had 3 diodes, he decided to try to combine the 3 low power beams into one high power beam. This can be done using a prism. A prism splits sunlight into a rainbow of colors because each wavelength(color) of light that passes through the prism is bent a different amount. Since the laser diodes only put out one wavelength of light, the beam bends but does not split or diffuse. A 3D printed bracket points each laser diode at a 3-sided pyramidal prism which sends the combined beam of light straight out the bottom towards the object to be cut or engraved.

This project is cool enough that we would have covered it even if [Sp4rky] wasn’t burning a Hackaday logo. Although it doesn’t hurt for anyone wanting their project to get covered!