From Schematic To PCB In Four Hours

February 13, 2014 by Abe Connelly 25 Comments

lpkf_metrix

Last super bowl Sunday, instead of checking the game, [Mattw] decided to extend a design and make a PCB of a trinket clone. [Mattw] altered a trinket clone design by [Morgan ~~Penfield~~ Redfield] to shrink it down, perforated the USB connector to allow for easy removal and put most of the parts on a single layer.

After finalizing the design, [Mattw] put it into the LPKF Protolaser S that Seattle’s Metrix Create Space has. For those of you who don’t know, the LPKF protolaser uses a laser to directly ablate off the copper from the boards. This makes prototyping much faster without the need for a lot of nasty chemicals.

About six minutes in the Protolaser, some component placement by hand followed by a run through their reflow oven and [Mattw] had three boards ready to be tested. All told, about 4 hours from start to finish.

The end circuit looks great and the LPKF protolaser gives us a case of serious tool envy. If you’re like us and don’t have access to the fancy laser you might try our hand at this high-resolutino photo-etch process.

[via reddit]

Fail Of The Week: Oil Expeller And Hasty PCB Layout

February 6, 2014 by Mike Szczys 38 Comments

This Fail of the Week is a twofer. On the left we have an attempt to heat the output of an oil expeller. After a bountiful crop of sunflower seeds [Mark] picked up the oil expeller to make is own cooking oil. He tried to use the soldering gun as a heat source but after just a couple of minutes of on-time it melted the soldering iron’s plastic case. He’s looking for an alternate heat source but we wonder why he can’t just ditch the plastic and bolt this to a heat sink?

To the right is the product of hasty PCB layout. [Andrew] needed a USB to GPIO converter to use with his Android stick. He had built several of these before, etching the PCBs himself. But now he didn’t have the time to do his own etching and figured he could lay out a revision of the board and have it fabbed. Turns out this isn’t the time saver he had hoped. Problems with the location of silk screen labels aren’t a huge deal, but the ‘V’ in the board where his USB connector is located blocked any cable he tried to plug in. A bit of cutting solved that but he also had to deal with spring terminals whose leads wouldn’t fit the diameter of holes drilled in the board. We always print out the Gerbers and compare the footprints to our parts before submitting to the fab house. But we’re not sure we would have caught the USB cable clearance issue doing it that way. What checklists do you use before submitting your own boards?

Fail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.

Laser-Based PCB Printer

February 3, 2014 by Rich Bremer 62 Comments

Being able to create PCB’s at home is a milestone in the DIYer’s arsenal. Whether you physically mill or chemically etch boards, it’s a tricky task to perfect. [Charlie & Victor] are working towards a solution to this complicated chore. They call their machine the DiyouPCB. DiyouPCB is an open source PCB etching project consisting of both hardware and software components.

The project is based on using a Blue Ray optical pickup. The pickup was used in its entirety, without any modification, to simplify the build process. In order to use the stock pickup, [Charlie & Victor] had to reverse engineer the communication protocol which also allowed them to take advantage of the auto-focus feature used while reading Blue Ray discs. The frame of the machine is reminiscent of a RepRap, which they used to do preliminary testing and laser tuning. The X and Y axes run on brass bushings and are belt driven by stepper motors which are controlled by an Arduino through a specially designed DiyouPCB Controller Shield.

Continue reading “Laser-Based PCB Printer” →

[CNLohr] Demos His Photoetch PCB Process

January 31, 2014 by Brian Benchoff 25 Comments

etch

If you’re going to learn something, it only makes sense to learn from a master. [CNLohr] is known around these parts for his fablous PCBs, and he’s finally started to document his entire fabrication process.

[CNLohr] is using a photoetch process, where a mask is created with a laser printer on overhead transparencies. He covers the copper clad boards with a Riston photosensitive mask—available here, and they accept Bitcoin—sent through a laminator, and exposed with the laser printed mask and a UV grow bulb. After the mask has developed, [CNLohr] drops his boards into a ferric chloride bath that eats away the unexposed copper. He then removes the photomask with acetone and cuts the boards with a pair of aircraft snips, and they’re ready to be soldered up with components.

Yes, home PCB etching tutorials are pretty much a solved problem, but [CNLohr]’s work speaks for itself. He’s also the guy who made a microcontroller/Linux/Minecraft thing on a glass microscope slide. Learning from a guy with these skills means you’re learning from one of the best.

Video below, and there’s also a video going over the design of a PCB using KiCAD (!) and TopoR (!!!) available here.

Continue reading “[CNLohr] Demos His Photoetch PCB Process” →

Toner Transfer PCBs, Double Sided, With Color Silkscreen

January 27, 2014 by Brian Benchoff 38 Comments

Silk

Making a few PCBs with the toner transfer method is a well-known technique in the hacker and maker circles. Double-sided PCBs are a little rarer, but still use the same process as their single-sided cousins. [Necromancer] is taking things up a notch and doing something we’ve never seen before – double-sided PCBs made at home, with color silkscreens, all make with a laser printer.

For laying down an etch mask, [Necro] is using a Samsung ML-2167 laser printer and the usual toner transfer process; print out the board art and laminate it to some copper board.

The soldermasks use a similar process that’s head-slappingly similar and produces great results: once the board is etched, he prints out the solder mask layer of his board, laminates it, and peels off the paper. It’s so simple the only thing we’re left wondering is why no one thought of it before.

Apart from the potential alignment issues for multiple layers, the only thing missing from this fabrication technique is the ability to do plated through holes. Still, with a laser printer, a laminator, and a little bit of ferric or copper chloride you too can make some very nice boards at home.

Testing The Limits Of Home PCB Etching

January 5, 2014 by Brian Benchoff 70 Comments

[Quinn Dunki]’s Veronica, a homebrew computer based on the 6502 CPU, is coming along quite nicely. She’s just finished the input board that gives Veronica inputs for a keyboard and two old Nintendo gamepads. [Quinn] is building this computer all by her lonesome, including etching all the PCBs. She’s gotten very, very good at etching her own boards, but this input board did inspire a few facepalming moments.

In an earlier post, [Quinn] went over her PCB etching capabilities. As demonstrated by the pic above, she’s able to print 16 mil traces with 5 mil separation. This is just about as good as you can get with homebrew PCBs, but it’s not without its problems.

[Quinn] is using a photographic process for her boards where two copies of a mask is printed on an acetate sheet, doubled up, and laid down on a pre-sensitized copper board. The requirement for two layers of toner was found by experience – with only one layer of toner blocking UV light, [Quinn] got some terrible pitting on her traces and ground planes.

Two photographic masks means the masks must be precisely aligned. This example shows what happens when the acetate sheets are ever so slightly misaligned. With a 5 mil gap between traces, [Quinn] needs to align the masks to within ±2.5 mils; difficult to do by eye, and very hard once you factor in flexing and clamping them down to the copper board.

Even when this process goes perfectly, [Quinn] is pushing the limits of a laser printer. When printing at 600 dpi, the pixels of the print are about 1.5 mils. While GIMP, printer drivers, and the printer itself have some fancy software to help with the interpolation, [Quinn] is still seeing ‘bumps’ on the edges of perfectly aligned parts. This is one of those things that really makes you step back and realize how amazing fabbing PCBs at home actually is.

With most of the hardware for Veronica out of the way, it’s just about time for [Quinn] to start programming her baby. We’re not expecting a full-blown operating system and compiler, but those NES gamepads are probably crying out for some use.

A Touch Scroll Wheel Via OpenSCAD

December 8, 2013 by Brian Benchoff 9 Comments

touch

Recent experiments with the Arduino CapSense library led [Bryan] around the Internet looking for interesting applications. He hit upon a very cool touch scroll wheel made entirely with PCB traces, but the geometry – three interleaved zig zags is impossible to build in the decidedly ungeometric Eagle PCB package. One thing leads to another and now [Bryan] has a cap touch wheel Eagle part designed entirely in OpenSCAD.

The touch scroll wheel implementation [Bryan] found came from an ST touch controller datasheet and used oddly-shaped patterns to create a capacities sensor. Eagle is terrible for designing anything that isn’t laid out at a 45 degree angle, so he fired up OpenSCAD to draw these triangles. Importing into Eagle was another challenge, but a quick Ruby script to convert a DXF file into a set of coordinates for Eagle’s POLYGON command made everything very easy.

If OpenSCADing touch sensors isn’t your thing, there’s also an Eagle library full of them – something we found last week.