Ask Hackaday: Stripping Wires With Lasers

September 8, 2022 by Al Williams 22 Comments

Most of us strip the insulation off wires using some form of metal blade or blades. You can get many tools that do that, but you can also get by with skillfully using a pair of cutters, a razor blade or — in a pinch — a steak knife. However, modern assembly lines have another option: laser stripping. Now that many people have reasonable laser cutters, we wonder if anyone is using laser strippers either from the surplus market or of the do-it-yourself variety?

We are always surprised that thermal strippers are so uncommon since they are decidedly low-tech. Two hot blades and a spring make up the heart of them. Sure, they are usually expensive new, but you can usually pick them up used for a song. The technology for lasers doesn’t seem very difficult, although using the blue lasers most people use in cutters may not be optimal for the purpose. This commercial product, for example, uses infrared, but if you have a CO₂ laser, that might be a possibility.

The technique has found use in large-scale production for a while. Of course, if you don’t care about potential mechanical damage, you can get automated stripping equipment with a big motor for a few hundred bucks.

We did find an old video about using a CO₂ laser to strip ribbon cable, but nothing lately. Of course, zapping insulation creates fumes, but so does lasering everything, so we don’t think that’s what’s stopping people from this approach.

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Cutting The Grass With Frickin’ Lasers

September 2, 2022 by Dave Rowntree 29 Comments

We techie types are quite often much more comfortable in front of a keyboard knocking out code, than out in the yard splitting logs for winter, and even the little jobs like cutting the grass are sometimes just too much like hard manual labour for our liking. The obvious solution is a robot mower, but they’re kinda boring, with their low-tech spinning metal blades. What we need is a big frickin’ laser. YouTuber [rctestflight] has been experimenting with using a 40W blue diode laser module to cut the weeds, (Video, embedded below) and it sort of works, albeit in a rather dangerous fashion.

The first test used a fixed assembly, mounting the laser to a camera lens, upon a rotating gear driven by a small stepper motor. An Arduino controls the beam scanning, very slowly, burning the grass in its sights. But with a range limited to around eight feet best case, sitting in one spot just isn’t going to cut it. (sorry) The obvious next step was to mount one of the tested laser modules onto a moveable platform. After tweaking one of his earlier projects — a tracked rover — with a new gearbox design, it could now drive slow enough to be useful for this slow task. The laser was mounted to a simple linear rail slider, with an attempt at a vacuum pickup system to suck up the clippings, removing them from the beam path, and stopping them impeding the cutting efficiency of the laser.

Obviously this vacuum idea didn’t work, and since the contraption takes the best part of a week to cut just one small area, we reckon it would likely be growing faster than that! Still, it must have been fun to build it anyway. It just goes to show that despite the march of technological progress, maybe the boring old spinning blades of old are still the best way to get the job done.

Lawnmowing is clearly one of those jobs we love to hate, and do so with hacks. Here’s a way to prevent your mower sucking up foreign bodies and hurling them at you at ballistic speeds, and for those who really want to be hands off, add RTK-GPS to a robot mower, and just leave it to do the dirty work.

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Demonstrate Danger, Safely

July 30, 2022 by Elliot Williams 67 Comments

Dan Maloney and I were talking about the chess robot arm that broke a child’s finger during the podcast, and it turns out that we both have extreme respect for robot arms in particular. Dan had a story of a broken encoder wheel that lead to out-of-control behavior that almost hit him, and I won’t even get within striking distance of the things unless I know they’re powered off after seeing what programming errors in a perfectly functioning machine can do to two-by-fours.

This made me think of all the dangerous things I’ve done, but moreover about all the intensely simple precautions you can to render them non-risky, and I think that’s extremely important to talk about. Tops of my list are the aforementioned industrial robot arm and high powered lasers.

Staying safe with an industrial robot arm is as easy as staying out of reach when it’s powered. Our procedure was to draw a line on the floor that traced the arm’s maximum radius, and you stay always outside that line when the light is on. It’s not foolproof, because you could hand the ’bot a golf club or something, but it’s a good minimum precaution. And when you need to get within the line, which you do, you power the thing down. There’s a good reason that many industrial robots live in cages with interlocks on the doors.

Laser safety is similar. You need to know where the beam is going, make sure it’s adequately terminated, and never take one in the eye. This can be as simple as putting the device in a box: laser stays in box, nobody goes blind. If you need to see inside, a webcam is marvelous. But sometimes you need to focus or align the laser, and then you put on the laser safety glasses and think really hard about where the beam is going. And then you close the box again when you’re done.

None of these safety measures are particularly challenging to implement, or conceptually hard: draw a line on the floor, put it in a box. There were a recent series of videos on making Lichtenberg figures safely, and as a general rule with high voltage projects, a great precaution is a two-button deadman’s switch box. This at least ensures that both of your hands are nowhere near the high voltage when it goes on, at the cost of two switches.

If all of the safety precautions are simple once you’ve heard them, they were nothing I would have come up with myself. I learned them all from other hackers. Same goes with the table saw in my workshop, or driving a car even. But since the more hackery endeavors are less common, the “common-sense” safety precautions in oddball fields are simply less commonly known. It’s our jobs as the folks who do know the secrets of safety to share them with others. When you do something dangerous, show off your safety hacks!

Interesting Optics Make This Laser Engraver Fit In A Pocket

July 24, 2022 by Dan Maloney 37 Comments

We’re going to start this post with a stern warning: building a laser engraver that can fit in your pocket is probably not a wise idea. Without any safety interlocks and made from lightweight components as it is, this thing could easily tip over and sear a retina before you’d even have time to react. You definitely should not build this, or even be in the same room with it. Got it?

Safety concerns aside, [DAZ] has taken a pretty neat approach to making this engraver, eschewing the traditional X-Y gantry design in favor of something more like the galvanometers used for laser projectors, albeit completely homebrew and much, much slower than commercial galvos. Built mostly of 3D-printed parts, the scanning head of this engraver uses a single mirror riding on an angled block attached to gimbals with two degrees of freedom. The laser module and mirror gimbals are mounted on a stand made of light aluminum so that the whole thing is suspended directly over a workpiece; the steppers slew the mirror to raster the beam across the workpiece and burn a design.

The video below shows it at work, and again, we have to stress that this is about as close to this build as you should get. It shouldn’t be too hard to add some safety features, though — at a minimum, we’d like to see a tilt-switch that kills power if it’s knocked over, and maybe some kind of enclosure. Sure, that would probably spoil the pocketability of the engraver, but is that really a feature valuable enough to risk your eyesight for?

If there’s a laser build in your future, please read our handy guide to homebrew laser cutter safety — before you can’t.

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Ortur Laser Will Go Open-Source

July 18, 2022 by Elliot Williams 76 Comments

Well, that was fast! Last week, we wrote about a video by [Norbert Heinz] where he called out the Ortur laser engravers for apparently using the GPL-licensed grbl firmware without providing the source code and their modifications to it, as required by the license. Because open source and grbl are dear to our hearts and CNC machines, we wrote again about Norbert’s efforts over the weekend, speculating that it might just be unfamiliarity with the open source license requirements on Ortur’s part.

Because of [Norbert]’s persistance and publicity around the issue, the support ticket finally reached the right person within Ortur, and within two or three days [Gil Araújo], Support Admin at Ortur, managed to convince the company that going fully open source was the right thing to do. What remains is the question of how to do it, operationally.

So [Gil] asked [Norbert] to ask Hackaday: what do you want from Ortur on this, and how should they proceed? Via e-mail, he asked in particular for best practices on setting up the repository and making the code actually useful to non-programmer types. He said that he looked around at the other laser engraver companies, and didn’t find any good examples of others doing the Right Thing™, so he asked [Norbert] to ask us. And now we’re asking you!

Have you got any good examples of companies using open-source firmware, modifying it, and making it available for their users? Is a simple Github repo with a README enough, or should he spend some time on making it user-friendly for the non-coders out there? Or start with the former and work toward the latter as a goal? I’m sure [Gil] will be reading the comments, so be constructive! You’ll be helping a laser engraver company take its first steps into actually engaging with the open source community.

We said it before, and we’ll say it again. Good job [Norbert] for taking Ortur to task here, but also by doing so in a way that leaves them the option of turning around and doing the right thing. This also highlights that companies aren’t monolithic beasts – sometimes it takes getting your cause heard by just the right person within a company to change the response from a “this is a business secret” to “how should we set up our Github?” And kudos for [Gil] and Ortur for listening to their users!

Collaborative Effort Gets Laser Galvos Talking G-Code

July 15, 2022 by Dan Maloney 9 Comments

Everyone should know by now that we love to follow up on projects when they make progress. It’s great to be able to celebrate accomplishments and see how a project has changed over time. But it’s especially great to highlight a project that not only progresses, but also gives back a little to the community.

That’s what we’re seeing with [Les Wright]’s continuing work with a second-hand laser engraver. It was only a few weeks ago that we featured his initial experiments with the eBay find, a powerful CO₂ laser originally used for industrial marking applications. It originally looked like [Les] was going to have to settle for a nice teardown and harvesting a few parts, but the eleven-year-old tube and the marking head’s galvanometers actually turned out to be working just fine.

The current work, which is also featured in the video below, mainly concerns those galvos, specifically getting them working with G-code to turn the unit into a bit of an ad hoc laser engraver. Luckily, he stumbled upon the OPAL Open Galvo project on GitHub, which can turn G-code into the XY2-100 protocol used by his laser. While [Les] has nothing but praise for the software side of OPAL, he saw a hardware hole he could fill, and contributed his design for a PCB that hosts the Teensy the code runs on as well as the buffer and line driver needed to run the galvos and laser. The video shows the whole thing in use with simple designs on wood and acrylic, as well as interesting results on glass.

Of course, these were only tests — we’re sure [Les] would address the obvious safety concerns in a more complete engraver. But for now, we’ll just applaud the collaboration shown here and wait for more updates.

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A Home Made Laser Cutter For $700

June 29, 2022 by Matthew Carlson 36 Comments

While some decent lasers are out there for under $400 USD, they tend to be a little small. What if you wanted something a little nicer but didn’t want to jump to the $2,000 category? The answer for [Owen Schafer] was to build it with parts he had lying around and a few strategic purchases.

While he was initially planning on using a diode laser, doing anything more than engraving is tricky. He purchased a cheap 40 W CO2 laser tube, but it meant that he needed water cooling, mirrors, and more complex stuff that a diode doesn’t need. The frame is aluminum extrusion held together with 3D printed plates. Given there was a powerful laser bouncing around with mirrors, a plywood box formed the enclosure.

The stepper controller is an Arduino Mega running the Marlaser firmware, though [Owen] admits perhaps a laser cutter-specific driver board would have been better as he spent many hours trying to get the Arduino to do what he wanted. Air ventilation is a tube with a fan that vents out a nearby window. Water cooling is just a bucket of water with a pump in it. A simple nylon hose connected to a compressor with a maximum airflow valve provides an air assist while cutting. Finally, we’re happy to report that [Owen] bought safety glasses specific to his laser to protect his eyes and researched how to ground the high voltages generated.

We particularly loved seeing all of [Owen’s] test cuts. He proudly displayed his boxes, sharks, and lamp shades like anyone with their new laser cutter is wont to do. If you’re looking to upgrade your laser, there’s an add-on for detecting materials optically or a relatively cheap laser bed you can throw in your laser.

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