Laser Cut Enclosures from Eagle Files

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.

One Person’s Experience Of Having PCB Assembly Done In China

Those of us who have our PCBs manufactured by Chinese PCB fab houses will be used to seeing tempting offers to also assemble our completed boards. Send the Gerbers as normal, but also send a BoM, and for an extra slice of cash you can receive fully assembled PCBs instead of just bare boards. It sounds alluring, but leaves a few questions for those without the experience. How much will it cost, what will the quality be like, and will my boards work? [Alexander Lang] had a limited run of ten small pressure sensor boards to make, and since his board house had started an assembly service,  decided to take the plunge and opt for full assembly.

His first step was to assemble his BoM and send it with the Gerbers. He is at pains to stress that the BoM is key to the whole project, and getting it right with the correct packages and more than one source for each component is critical. The board house first charged him £32.05 ($41.76) to make his PCBs and stencil, and assess his BoM for a build quote. A few days passed, and then he had a quote for assembly, £61.41 ($80). He placed the order, the board house processed it and made the boards, and in due course his working PCB modules arrived.

This might sound at this point like an unexciting saga, but its very smoothness is the key to what makes it interesting. Those of us who have wondered about the risks involved in taking up such a service need to hear stories like this one as surely as we do stories of failure, because without them we’re flying blind. Whether £93.46 ($121.76) for ten small boards represents good enough value is another matter, but if surface-mount soldering is not your thing you might be interested to follow [Alexander]’s example. After all, it wasn’t so long ago that getting a cheap PCB made in China was a similar leap of faith.

Friday Hack Chat: PCB Manufacturing

There’s a world of difference between building one of something and building multiples of something. The effort that goes into manufacturing does not scale linearly, and manufacturing is a skill in itself. This Friday, we’re going to be talking all about PCB manufacturing and assembly over on Hackaday.io

On deck for this Hack Chat will be [Jonathan Hirschman], the brains behind PCB:NG, a turnkey electronics manufacturing startup based around NYC. Jonathan is a self-taught hardware guy, proficient in PCB layout, 3D CAD, and manufacturing tech. PCB:NG is, essentially, taking oldskool manufacturing and making it into more of a digital process. PCB:NG makes it easy for anyone to get their designs manufactured, and to do it in the most cost-effective manner.

What is this Hack Chat going to be about? We’re going to talk about how to get started in PCB creation. What is the the best tool for the job? What is the best tool that doesn’t cost as much as a car? What are the pros and cons of each tool, and what should you know about RF before designing a board that blinks a LED?

This isn’t a Hack Chat that’s just about PCBs, though. We’re also going to be talking about manufacturing. Specifically, design for manufacturing, how to panelize boards, what happens when you forget fiducials, how to keep your designs cheap to manufacture, what happens when you put SMD components on both sides of a board.

We’re taking questions from everyone, so feel free to add something to the question sheet for the discussion.

We’re Looking For Hack Chat Hosts!

If PCB manufacturing and design isn’t your thing — or even if it is — we’re on the lookout for Hack Chat hosts. If you have some expertise in an area, give us a ring. We’ve already had a few chats with Raspberry Pi engineers, one of the brilliant people behind the ESP32, a talk on ASIC design for mixed signal oscilloscopes, and high-end audio amplifiers. We’re taking all callers, and if you have something you’d like to share with the community, send us an email. I would like to mention that it’s Burner season, and a few chats with the artists on the playa would be great, especially if they can tell us how to move the fuselage of a 747 a few hundred miles.

Here’s How To Take Part:

join-hack-chatOur Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This Hack Chat will take place at noon Pacific time on Friday, August 4th. Confused about where and when ‘noon’ is? Here’s a time and date converter!

Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Rapidly Prototyping RF Filters

RF filters are really just a handful of strategically placed inductors and capacitors. Yes, you can make a 1 GHz filter out of through-hole components, but the leads on the parts turn into inductors at those frequencies, completely ruining the expected results in a design.

The solution to this is microstrip antennas, or carefully arranged tracks and pads on a PCB. Anyone can build one of these with Eagle or KiCad, but that means waiting for an order from a board house to verify your design. [VK2SEB] has a better idea for prototyping PCB filters: use copper tape on blank FR4 sheets.

The first, and simplest, filter demonstrated is a simple bandstop filter. This is really just a piece of fiberglass with copper laminated to one side. Two RF connectors are soldered to the edges and a strip of copper tape strung between them. Somewhere around the middle of this copper tape, [VK2SEB] put another strip of copper tape in a ‘T’ configuration. This is the simplest bandstop filter you can make, and the beauty of this construction is that it can be tuned with a razor blade.

Of course, a filter can only be built with copper tape if you can design them, and for that [SEB] is turning to software. The Qucs project is a software tool for designing and simulating these microstrip filters, and after inputting the correct parameters, [SEB] got a nice diagram of what the filter should look like. A bit of taping, razor blading, and soldering and [SEB] had a working filter connected to a spectrum analyzer. Did it work? To a limited extent; the PCB material probably wasn’t right, and board houses are more accurate than a razor blade, but [SEB] did manage to create a 10 GHz filter out of fiberglass and copper tape.

You can check out the video for this experiment below.

Continue reading “Rapidly Prototyping RF Filters”

Fail Of The Week: How Not To Use Pushbuttons

If you are a regular at creating printed circuit boards, it is likely that somewhere in your shop there will be a discard pile of boards on which you placed a component in the wrong orientation such that it would not work. It’s easily done, and don’t be shy to admit it if it’s happened to you.

[Bill] was making his own ARM developer board, taking inspiration from the ARM Pro Mini. He produced his PCB design and sent it off to the board house, and in due course received and reflow soldered a batch of beautiful dev boards. On power-up though, something was wrong! No USB device detected on his computer, a disaster. A lot of studying board and schematic led to the discovery that his push-button switches had been placed at 90 degrees to the orientation it should have had, leaving them in a permanently “on” position.

The PCB bug makes this is a Fail Of The Week post, but he transformed into a win with some experimentation with the switch outline in KiCAD before finding a way to mount the switches on the pads at 45 degrees, covering three of the pads. Well done, and well done for admitting the error.

[Editor’s note: been there, done that. One way to prevent the error is to only connect to diagonally opposite pins of the tact switch, so the rotation doesn’t matter.]

Having earlier asked others to come clean with their PCB mistakes, it’s probably appropriate to admit that Hackaday scribes are just as fallible as [Bill] when it comes to PCB layouts. Somewhere there may still be a board on this bench with a QFN microcontroller bodged on at 90 degrees to its original orientation, with cut tracks and tiny wire runs.

Whether you are a seasoned PCB pro or a wet-behind-the-ears rookie, our Creating a PCB In Everything series should be of interest.

Laser Exposing PCBs With A Blu-Ray Laser

For those of us whose introduction to PCB making came decades ago and who share fond memories of permanent markers and crêpe paper sticky tape, the array of techniques available to PCB artists of today seem nothing short of magical. Toner transfer and peroxide etchant mixtures might seem run-of-the-mill to many readers, but even they are streets ahead of their predecessors from times past.

Photographic exposure of  etch-resist coating has traditionally been performed with a UV lamp through a sheet of acetate film, but there is no reason why that should be the only way it can be performed. There have been plenty of projects using lasers or LEDs to draw a PCB design onto the coating as a raster, and a rather nice example from [Terje Io] using a Blu-Ray laser diode is the subject of the video below the break.

The diode is mounted on a gantry with a THK KR33 linear actuator that he tells us was unsuitable for his CNC mill due to backlash. This gives a claimed 1200 dpi resolution, over a 100 mm x 160 mm exposure area. Software is provided in a GitHub repository, taking a PNG image exported through a PDF printer. And since it’s got a UV laser, it can be used in a second pass to process UV-responsive soldermask film. ([Terje] cheats and uses a separate CNC mill to drill out the holes.) The result looks great.

Continue reading “Laser Exposing PCBs With A Blu-Ray Laser”

Hackaday Prize Entry: PCBs On Demand with Etchr

The ambitious etchr – the PCB Printer is just a concept at the moment, but it’s not often we see someone trying to tackle desktop PCB production in a new way. Creator [Jonathan Beri] is keenly aware that when it comes to creating electronics, the bottleneck for most workflows is the PCB itself. Services like OSH Park make professionally fabricated PCBs accessible at a low cost, but part of the bargain is that turnaround times are often measured in weeks.

[Jonathan]’s concept for etchr is a small system that automates not only etching a copper-clad board with all the attendant flooding and draining of chemicals, but applying a solder mask and silkscreen layer labeling as well. The only thing left to do would be to drill any required holes.

The idea behind etchr is to first take a copper-clad board with photoresistive film or spray applied to it, and fix it into a frame. A UV projector takes care of putting the traces pattern onto the board (and also handles a UV-curable solder mask in a later step) and the deep frame doubles as a receptacle for any chemical treatments such as the etching and cleaning. It’s an ambitious project, but the processes behind each step are well-understood and bringing them all together in a single machine is an intriguing approach.

Desktop production of PCBs can be done in a few ways, including etching via the toner transfer method (whose results our own Elliot Williams clearly explained how to take from good to great). An alternative is to mill the PCBs out directly, a job a tool like the Othermill is designed specifically to do. It’s interesting to see an approach that includes applying a solder mask.