Milling A Flow Sensor To Safeguard A Laser Tube

September 29, 2017 by Mike Szczys 16 Comments

Powerful lasers get powerfully hot and if you don’t keep them cool you’ll pay the price. After two such experiences [NixieGuy] got smart and milled this flow sensor as a failsafe.

Laser cutters are awesome. But acquiring one can be expensive, and keeping them in working order is no small feat. From the gunk that builds up as a byproduct of vaporizing the cutting stock, to keeping the optics focused correctly, it’s a game that forces you to become a laser cutter operator and not merely a user. One of the worst things to deal with is having to replace a burnt out laser tube. They do have a life to them but in this case the filter on the water cooling system clogged and the tube cooked itself. Twice.

This flow sensor now acts as an interconnect with the laser enable line. Starting with an acrylic rod, [NixieGuy] machined out a center hole for a magnetic stopper, then milled three channels for water to pass around it. Each end of the rod was turned on a lathe to interface with plastic tubing of the water cooling system, and a slot was milled on the outside for a reed switch.

The demo video is below. You can see that when water flows it pushes the magnetic stop up (against gravity) where it engages the reed switch, allowing the laser to operate. If something impedes the flow of water (even if the pump still runs) the laser will be disabled and (hopefully) prevent future tube loss.

Want to see some of the oops moments faced by many a laser cutter operator? Check our guide on how to fail at laser cutting.

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Laser Smoothies At Maker Faire

September 24, 2017 by Brian Benchoff 25 Comments

This year at Maker Faire, laser cutters were all the rage. Dremel announced a 40W laser cutter, but it won’t be available for purchase until this time next year, there is no price yet, and therefore doesn’t deserve further mention. Glowforge was out in full force, but the most interesting aspect of the Glowforge — a compact filter system that sits right underneath the laser — was not to be found. It looks like lasers are the next 3D printer.

Of course, those in the know have already been using laser cutters for years, and there are options for desktop CO2 laser cutters that cost less than a kilobuck. I speak, of course, of the ubiquitous K40 laser, a machine you can get off of eBay or AliExpress for the price of a generic, off-brand 3D printer. There is a downside to the K40, though: the control electronics and software are notoriously terrible. Fix that, though, and you have something really spectacular.

This year at Maker Faire, [Ray Kholodovsky] of Cohesion3D brought out his Smoothie-derived control boards for CNC machines and laser cutters. Of note is his K40 upgrade that turns the eBay special laser cutter into a 32-bit professional machine. This is the cheapest way to start lasing in your workshop.

We saw [Ray] at the Faire last year when he was demoing his Smoothie-derived boards for 3D printers and CNC machines. These are tiny, relatively low-cost boards that use Smoothieware, an Open Source, 32-bit CNC control system that is extremely extensible and very powerful. Basically, if you’re building a normal, ordinary DIY 3D printer, a RAMPS or RAMBO will do. If you’re doing something weird, like a 3D printer with strange kinematics, a 5-axis milling machine, or you’d like awesome engraving on a laser cutter, Smoothie is the way to go.

The stock board found in a K40 (left) and the Cohesion3D Mini (right). The Cohesion3D Mini is a drop-in replacement for the stock K40 board.

The Cohesion3D board is a direct, drop-in replacement for the control board found in the K40 laser. Since all of the K40 laser cutters are the same, and they’re really only a power supply and a CNC gantry, this is the one-stop-shop of K40 upgrades. The terrible electronics are gone, you don’t have to use Corel, and for a hundred bucks, you have something resembling a professional laser cutter.

The K40 laser has been around for several years now, but only recently have a few very interesting hacks and mods come out that push this blue light special laser cutter into semi-professional territory for people willing to get their hands dirty. A few months ago [Scorch] published K40 Whisperer, a piece of software that makes the stock electronics tolerable and able to accept normal SVGs and DXFs. The K40 has also been modified for a larger bed, and LaserWeb has been handling the software side of things for about two years now. Things are looking great for the K40 hacking scene, and Hackaday already has a, ‘I just bought a K40, now what?’ series in the works. Things are looking up for cheap laser cutters, and a Smoothie upgrade is just the cherry on top.

Modular Storage With Peanut Butter And Lasers

August 23, 2017 by John Baichtal 22 Comments

I have storage on the mind, and it comes from two facts in my life:

First, I have tons of stuff in my workshop, far too much for the amount of space I have. A lot of this material is much easier to use if it’s well-organized. Think electronics, robotics, building sets. Modular parts that need to go together a certain way for them to be useful. It is imperative, therefore, that I come up with some sort of organization system to keep the chaos in check.

Second, my favorite tool is the laser cutter, born from my love for building vector designs. I can do art on the computer and have it manufactured in front of my eyes, and share my designs with someone else who can remix it into something even cooler.

So with those two facts in mind, I set about creating a modular storage system in Inkscape and cutting out the design from pine boards using a laser cutter. Let us go on a journey through my thought process:

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Laser Etching PCBs

August 22, 2017 by Brian Benchoff 63 Comments

A while ago, [Marco] mounted a powerful laser diode to a CNC machine in an attempt to etch copper clad board and create a few PCBs. The results weren’t that great, but the technique was promising. In a new experiment, [Marco] purchased a very cheap laser engraver kit from China, and now this technique looks like it might be a winner.

[Marco] sourced his laser engraver from Banggood, and it’s pretty much exactly what you would expect for a CNC machine that costs under $200. The frame is aluminum extrusion, the motors are off-the-shelf steppers, the electronics are just Pololu-like drivers, and the software is somewhere between abysmal and terrible. Nevertheless, this machine can cut wood, leather, fabric, and can remove spray paint with a big blue laser diode.

To create his PCBs, [Marco] is first cleaning a piece of copper clad board, coating it with spray paint, then blasting it with a laser. The preferred software for this is LaserWeb, and the results are pretty good for a cheap machine.

There are a few extra steps to creating the PCB once the board has been coated with paint and blasted with a laser. This process still requires etching in either ferric chloride or some other mess of acid, but the results are good. So good, in fact, that [Marco] is experimenting with copper foil and Kapton to create flexible circuit boards. You can check out the video of these experiments below.

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Laser Cut Enclosures From Eagle Files

August 9, 2017 by Bryan Cockfield 16 Comments

Once a project is finished, it might still need a decent enclosure. While it’s possible to throw a freshly soldered PCB in a standard enclosure, or piece of Tupperware, or cardboard box, these options don’t have the fit and finish of something custom-made. If you have a laser cutter sitting around, it’s a simple matter to cut your own enclosure, but now that process is much easier thanks to [Ray]’s latest project.

Since [Ray] was already using Eagle to design his PCBs, it seemed like a short step to using the Eagle files to design the enclosure as well. The script runs from those files and creates everything necessary to send to the laser cutter for manufacturing. Right now, [Ray] points out that the assembly time for each enclosure can be high, and this method might not be suited for large numbers of enclosures. Additionally, some of the calculations still need to be done by hand, but there are plans to automate everything in the future.

For single projects, though, this script could cut a lot of time off of designing an enclosure and building it from scratch, and could also help improve aesthetics over other options like 3D printed enclosures. Of course, if you have a quality 3D printer around but no laser cutter, there are options for custom enclosures as well.

Take Control Of Your Cheap Laser Cutter

July 19, 2017 by Jenny List 24 Comments

The relatively inexpensive K40 laser cutter/engraver machines from China have brought laser cutting to the masses, but they are not without their faults. Sure, they’re only powerful enough for the lightest cutting tasks, but on top of that, their bundled software is inflexible and disappointing. If your workshop or hackspace has one of these machines languishing in the corner, then the release of a new piece of software, K40 Whisperer from [Scorch], is an interesting and welcome development.

He tells us that the reverse engineering process required to understand the K40’s protocol was non-trivial, given that it does not use handy decimal numbers to issue commands. A spreadsheet was used to collate data packets and spot repeating patterns to analyse the inner workings. Feature-wise, the software reads SVG and DXF files, and can split SVGs by colour. It has a halftone algorithm for rendering grey scales, and cuts from the inside of each shape first to avoid pieces of work dropping out of the piece of material. Currently it works with the stock M2 Nano controller board and is available as a Windows download, though it can also be compiled for Linux distributions, or MacOS, and he is asking owners to test it with as many machines as possible to ensure compatibility with other boards.

He has posted a video of K40 Whisperer in action, which you can see below the break.

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Kill The Exhaust, Not Your Lungs With The Fume Coffin

June 20, 2017 by Dan Maloney 8 Comments

As if slinging around 40 watts of potentially tattoo-removing or retina-singeing laser beams wasn’t anxiety-inducing enough, now comes a new, scary acronym – LCAGs, or “laser-generated airborne contaminants.” With something that scary floating around your shop, it might be a good idea to build a souped-up laser cutter exhaust fan to save your lungs.

We jest, but taking care of yourself is the responsible way to have a long and fruitful hacking career, and while [patternmusic]’s “Fume Coffin” might seem like overkill, can you go too far to protect your lungs? Plywood and acrylic, the most common materials that come across a laser cutter’s bed, both release quite a witch’s brew of toxins when vaporized by a laser beam. The Fume Coffin clears the air in your shop by venting it to the outdoors after giving it a good scrubbing through an activated charcoal pre-filter and a HEPA polishing element. Both filters are commercially available so replacements won’t be an issue, and the entire thing is housed in a wooden box that gives the device its name.

Since it’s ejecting 200 cubic feet per minute, you’ll have to provide at least that much make-up air, but other than that the Fume Coffin should be a welcome addition to the shop. We’ve seen a few other attempts to handle LCAGs effectively before, including a DIY charcoal and automotive air filter design.