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.

3D Printering: Laser Cutting 3D Objects

April 30, 2015 by Brian Benchoff 21 Comments

3D printing can create just about any shape imaginable, but ask anyone who has babysat a printer for several hours, and they’ll tell you 3D printing’s biggest problem: it takes forever to produce a print. The HCI lab at Potsdam University has some up with a solution to this problem using the second most common tool found in a hackerspace. They’re using a laser cutter to speed up part production by a factor of twenty or more.

Instead of printing a 3D file directly, this system, Platener, breaks a model down into its component parts. These parts can then be laser cut out of acrylic or plywood, assembled, and iterated on much more quickly.

You might think laser-cut parts would only be good for flat surfaces, but with techniques like kerf bending, and stacking layer upon layer of material on top of each other, just about anything that can be produced with a 3D printer is also possible with Platener.

To test their theory that Platener is faster than 3D printing, the team behind Platener downloaded over two thousand objects from Thingiverse. The print time for these objects can be easily calculated for both traditional 3D printing and the Platener system, and it turns out Platener is more than 20 times faster than printing more than thirty percent of the time.

You can check out the team’s video presentation below, with links to a PDF and slides on the project’s site.

Thanks [Olivier] for the tip.

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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!

Modern Tools From Old Table Saws

March 30, 2015 by Brian Benchoff 23 Comments

Somehow or another, the modern hackerspace isn’t centered around table saws, drill presses, band saws, lathes, or mills. The 3D printer and laser cutter are the tools of the future. No one has yet figured out how to build a 3D printer or laser cutter out of several hundred pounds of cast iron, so until then [Chad] will lead the charge modifying old table saws into these modern machine tools.

The build logs for the laser engraver and 3D printer are pic heavy and text lean, but there’s enough detail to make a few educated guesses. Both of these machines use Craftsman table saws from the early to mid 1950s for the chassis. Inside each chassis, the rails, belts, and shafts that make up a Cartesian bot are installed, and the electronics are tucked gently inside.

There’s a lot of creativity in this build; the electronics for the 3D printer are tucked away in the shell of the old motor. For the laser cutter, the focus adjustment is the same knob that used to lock the blade at an angle.

While this may look like a waste of two beautiful tools, keep in mind these are equivalent to contractor saws you can pick up at Home Depot for $500 today. They’re not professional cabinet saws, they just look really pretty. They’re still a solid piece of metal, though, and refurbishing the frames into useful tools is probably the best thing you could do with them.

Thanks [Frankie] for the tip.

Hackaday Links: March 29, 2015

March 29, 2015 by Brian Benchoff 14 Comments

Every once in a while, the Hackaday Overlords have a Hardware Developers Didactic Galactic in San Francisco. Last week was #06 featuring [Mike Estee] from Othermill and Hackaday writer [Joshua Vasquez] talking about synthesizing an SPI slave in an FPGA. Video here.

It’s no secret that [Fran] is building a DSKY – the part of the Apollo guidance computer that was on-screen in Apollo 13. It’s time for a project update, and here’s where she stands: if anyone has a source of JAN-spec Teledyne 420 or 422-series magnetic latching relays (they’re in a TO-5 package), contact [Fran]. The backplane connector has been identified; it’s a Teradyne I/O 100 series connector with a 120mil spacing. Contact [Fran] if you know where to get them.

Let’s say you want a carbon fiber quadcopter frame. What’s the most reasonable thing you can do? 3D print a CNC machine, obviously. That’s a 200mm FPV racer cut from 1mm and 3mm carbon fiber sheets, but the real story here is the CNC machine. It’s a PortalCyclone, and even the cable chains are 3D printed.

What does an AMOLED display look like up close? Pretty cool, actually. That’s 20x magnification, and it’s not a Bayer filter. Can anyone fill us in on the reason for that?

Laser cutters are tricky if you want to do grayscale or half tones. [oni305] made an Inkscape extension to generate better GCode for engraving with a laser cutter.

19″ racks have no dimensions that are actually 19″. Also 2x4s aren’t 2 inches by four inches. Somehow, a 2×4 server rack works.

Playing Space Invaders With Real Fire And Lasers

March 25, 2015 by Sarah Petkus 16 Comments

Making a Space Invaders game is up there on the list of most unconventional things you could do with a laser cutter. In watching the tiny little ships burst into flames, [Martin Raynsford’s] modification has got to be one of the more dangerous looking ones we’ve seen as well.

[Martin] always had the desire to make a tangible version of the classic game. Since his Whitetooth A1 laser cutter already contained the bulk of the moving hardware needed, not to mention an actual high powered laser to “pew pew” with, he decided it was the perfect starting point for such a project. The game is played looking down into the cutter since the laser of course fires in that direction, however a basic webcam is mounted to the laser assembly so that you can view the game on a computer screen at the proper perspective. An Arduino Mini is responsible for stepper control, allowing the player to jog back and forth and fire with a keyboard. [Martin] added an extra gear to the z-axis bed-leveler so that it could drive rows of paper invaders left and right across the bottom. Paperclips wedged into slots along a modified backboard hold each of the paper slips in place. This works ideally since they can be reloaded easily and won’t be maimed during use.

Due to the heat of the laser, landing a well positioned shot will likely nuke all of the nearby invaders as well, making for a theatrical inferno and easy win. Now to step up the difficulty level and figure out how to make them fire back…

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