Custom Inflatables Are Only A Laser Beam Away

April 2, 2019 by Tom Nardi 26 Comments

Carl Sagan one said “If you wish to make an apple pie from scratch, you must first invent the universe.” It might not be a very accurate description of the relative difficulty level of baking, but the logic is sound enough: there’s often a lot of ground work that needs to be to covered before you hit your ultimate goal. A perfect example of this principle is the inflatable raft that [ralph124c] hopes to eventually create; before he can set sail he has to perfect making balloon animals with his laser cutter.

In the long run, the raft will be constructed from sheets of TPU coated fabric that are fused together with a hot iron. But before he spends the time and money on building the real thing, he wants to do some scaled down tests to make sure his design works as expected. He makes a cryptic remark about learning the hard way that inflatables are prone to bouts of strange behavior, and out of an overabundance of caution we’ll just take his word for it.

He hoped to test his designs with the much cheaper LDPE film, but he found that the hot iron didn’t fuse it together in the way he was hoping. His mind turned to his 60 watt laser cutter, and wondered if the desired effect could be achieved by turning the power down as low as possible and quickly moving across the material.

His first attempts either blew right through the film or did absolutely nothing, but eventually he had the bright idea to move the laser farther from the LDPE. This put the beam out of focus, which not only expanded the area it would cover, but reduced the energy being delivered to the surface. With a bit more experimentation, he found he was able to neatly weld the pieces of material together. He even found that he could increase the power slightly to cut through the film without having to adjust the laser focus. With the ability to create complex inflatable shapes, perhaps [ralph124c] will create balloon version of Carl Sagan or an apple pie to celebrate.

Of course, this technology isn’t limited to birthday balloons and model rafts. The ability to quickly and easily produce custom inflatable shapes could be a huge boon to anyone working in soft robotics, and we’ve even seen similar concepts applied to haptic feedback systems.

[Thanks to Arthur for the tip.]

Eight Years Of Partmaking: A Love Story For Parts

February 8, 2019 by Sonya Vasquez 8 Comments

Over my many years of many side-projects, getting mechanical parts has always been a creative misadventure. Sure, I’d shop for them. But I’d also turn them up from dumpsters, turn them down from aluminum, cut them with lasers, or ooze them out of plastic. My adventures making parts first took root when I jumped into college. Back-in-the-day, I wanted to learn how to build robots. I quickly learned that “robot building” meant learning how to make their constituent parts.

Today I want to take you on a personal journey in my own mechanical “partmaking.” It’s a story told in schools, machine shops, and garages of a young adulthood spent making parts. It’s a story of learning how to run by crawling through e-waste dumps. Throughout my journey, my venues would change, and so would the tools at-hand. But that hunger to make projects and, by extension, parts, was always there.

Dear partmakers, this is my love letter to you.

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K40 Gets A Leg Up With Open Source Z Table

January 31, 2019 by Tom Nardi 14 Comments

If you’ve done even the most cursory research into buying a laser cutter, you’ve certainly heard of the K40. Usually selling for around $400 USD online, the K40 is not so much a single machine as a class of very similar 40 watt CO2 lasers from various Chinese manufacturers. As you might expect, it takes considerable corner cutting to drive the cost down that low, but the K40 is still arguably the most cost-effective way to get a “real” laser cutter into your shop. If you’re willing to do some modifications on the thing, even better.

One of the shortcomings of the K40 is that it lacks a Z axis, and with thick material that needs multiple cuts at increasingly deeper depths, this can be a hassle. [Aaron Peterson] decided to take it upon himself to design and build an adjustable Z table for the K40 at his local makerspace (River City Labs), and being the swell guy that he is, has made it available under an open source license so the rest of the K40-owning world can benefit from his work.

[Aaron] started the design with a number of goals which really helped elevate the project from a one-off hack to a sustainable community project. For one, he only wanted to use easily available commodity hardware to keep the cost down. The most complex components should all be 3D printable so the design would be easy to replicate by others, and finally, he wanted the user to have the ability to scale it in all dimensions. The end result is a electronically controlled lifting platform that anyone can build, for any laser cutter. It doesn’t even have to be limited to laser cutters; if you have a need for precisely raising or lowering something, this design might be exactly what you’re looking for.

The table is primarily constructed out of 15×15 aluminum extrusion, and uses standard hardware store expanded wire mesh as a top surface. Height is adjusted by rotating the four 95 mm T8 leadscrews with a GT2 belt and pulleys, which prevents any corner from getting out of sync with the others. Connected to a standard NEMA 17 stepper motor, this arrangement should easily be capable of sub-millimeter accuracy. It looks as though [Aaron] has left controlling the stepper motor as an exercise for the reader, but an Arduino with a CNC shield would likely be the easiest route.

We’ve seen a lot of hacking around the K40 over the last couple of years, from spring loaded beds to complete rebuilds which are hardly recognizable. If you’re looking for a cheap laser with a huge catalog of possible hacks and modifications, you could do a lot worse than starting with this inexpensive Chinese machine.

Spring-Loaded Bed For K40 Laser Acts As An Auto-Focus

December 2, 2018 by Donald Papp 12 Comments

Laser engraving and cutting has something in common with focusing the sun’s rays with a magnifying glass: good focus is critical to results. If materials of varying thicknesses are used, focus needs to be re-set every time the material changes, and manual focusing quickly becomes a chore. [Scorch Works] has a clever solution to avoid constant re-focusing that doesn’t involve sensors or motors of any sort. The result is a self-adjusting bed that compensates for material height changes, ensuring that the top surface of the material is always a fixed distance from the laser’s head.

The way [Scorch Works] has done this is to make two spring-loaded clamps from angle aluminum and a few pieces of hardware. When a sheet of material is placed into the machine, the edges get tucked underneath the aluminum “lips” while being pushed upward from beneath. By fixing the height of the top layer of angle aluminum, any sheet stock always ends up the same distance from the laser head regardless of the material’s thickness.

[Scorch Works] shows the assembly in action in the video embedded below, along with a few different ways to accommodate different materials and special cases, so be sure to check it out.

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Fail Of The Week: Did My Laser Cutter Tube Really Burn Out?

November 23, 2018 by Mike Szczys 28 Comments

All the cool kids are doing it these days, or more like for many years now: you can get a laser cutter for a song if you don’t mind doing your own repairs and upgrades — you know, being a hacker. The downside is that some failures can really ruin your day. This is what [Erich Styger] encountered with his cutter that is just a bit more than a year old. This Fail of the Week looks at the mysterious death of a CO2 laser tube.

This is the infamous K40 laser cutter. Our own [Adam Fabio] just took one on a couple of months back and [Erich] even references Hackaday coverage of the K40 Whisperer project as what pushed him over the edge to make the purchase. We’ve followed his blog as he acquired the cutter and made upgrades along the way, but after an estimated 500 hours of use, a horrible teeth-gnashing screech sprung forth from the machine. [Erich’s] reaction was to hit the e-stop; that’s certainly why it’s there.

Chasing down the problem is a story well-told, but as is often the case with these FotW articles, in the end what caused the failure is not entirely known. We’d love to hear what you think about it in the comments below.

The investigation began at the power supply for the laser, but that didn’t yield any answers. Next he moved to the tube itself, noticing that the wire connection to the tube’s anode wasn’t soldered. The anode is an unknown material he suspects to be graphite and he found a video showing the “soldering” process for connecting a wire. (We added quotes to that as the video he linked doesn’t actually solder anything but the wrapped wire strands themselves.) The solution he found is a great tip to take away from the story. It’s a socket by TE Connectivity to which he soldered the wire. Assuming it’s power rated for the task, and won’t fall off during normal operation, this is a great way to do it.

But we digress. Even with the connection made, the old tube had to be replaced with a new one. It’s also notable that the portion of that anode inside the bad tube is orange in color when a new tube would be black like the part on the outside. Does this hint at why that tube died, and could this have been avoided? If you have insight, help us learn from this failure by leaving a comment below.

Turn A Cheap 3D Printer Into A Cheap Laser Cutter

September 29, 2018 by Tom Nardi 26 Comments

We know it’s hard to hear it, but the days of you being a hotshot at the local Hackerspace because you’ve got a 3D printer at home are long gone. While they’re still one of the most persnickety pieces of gear on the hacker’s bench, they’re certainly not the rarest anymore. Some of these printers are so cheap now they’re almost impulse buys. Like it or not, few people outside of your grandmother are going to be impressed when you tell them you’ve got a personal 3D printer anymore; and we wouldn’t be surprised if even granny picked up a Monoprice Mini during the last open box sale.

But while 3D printer ownership isn’t the pinnacle of geek cred it once was, at least there’s a silver lining: cheap motion platforms we can hack on. [squix] writes in to tell us about how he added a laser to his $200 USD Tevo Tarantula 3D printer, greatly expanding the machine’s capabilities without breaking the bank. The information in his write-up is pretty broadly applicable to most common 3D printer designs, so even if you don’t have a Tarantula it shouldn’t be too hard to adapt the concept.

The laser is a 2.5 W 445 nm module which is very popular with low-cost laser cutter setups. It’s a fully self-contained air cooled unit that just needs a source of 12 V to fire up. That makes it particularly well suited to retrofitting, as you don’t need to shoehorn in any extra support electronics. [squix] simply connected it to the existing power wires for the part cooling fan he added to the Tarantula previously.

You may want to check the specs for your 3D printer’s control board before attaching such a high current device to the fan connector. Best case it just overloads the board’s regulator and shuts down, worst case the magic smoke might escape. A wise precaution here might be to put a MOSFET between the board’s fan output the and the laser, but we won’t tell you how to live your life. As far as laser safety, this device should probably work inside an opaque box, or behind closed doors.

Once the laser is hanging off the fan port of your printer’s controller, you can turn it on with the normal GCode commands for fan control, M106 and M107 (to turn it on and off, respectively). You can even control the laser’s power level by adding an argument to the “on” command like: M106 S30.

Then you just need to mount the laser, and it’s more or less business as usual. Controlling a laser engraver/cutter isn’t really that different from controlling a 3D printer, so [squix] is still using OctoPrint to command the machine; the trick is giving it a “3D model” that’s just a 2D image with no Z changes to worry about. We’ve seen the process for doing that in Inkscape previously.

With this laser module going for as little as $60 USD (assuming you’ve got a 3D printer or two laying around to do the conversion on), this is a pretty cheap way to get into the subtractive manufacturing game. Next stop from there is getting one of those K40’s everyone’s talking about.

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Lasercut Gears – A Learning Experience

August 2, 2018 by Lewin Day 7 Comments

Lasercutters are fantastic tools: they’re highly useful for making flat things, or even flat things that you later bend! This makes them particularly well suited for making gears out of flat stock. [sharvfish] needed to get his hands dirty with producing some gears for his automaton, and decided to share what he learned in the process.

The gears in question are cut out of MDF board, which is readily usable on all but the feeblest lasercutters you’ll find in the average makerspace. The first problem faced was when producing gears with low tooth counts – depending on the exact geometry used, teeth with lower counts can tend to jam easily. For [sharvfish]’s gears, 6 teeth seems to be just a touch too small to work well. Other issues cropped up around the kerf of the cuts affecting the gear mesh and the use of pins to improve the coupling of the gears to the shaft, which [sharvfish] expands upon in the video. There’s also a cheeky cephalopod cameo, too.

It’s always interesting to see the unique challenges faced in the undertaking of a project; we could see six more lasercut projects this week, and we’d likely see six unique problems the builders faced as well. It’s a great insight into the build process and it’s great when makers share their journey as well as the finished product. Video after the break.

Wondering what lasercut gears can do for you? Check out this build that rotates an entire television.

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