How To Laser Cut Mylar Solder Stencils

June 27, 2014 by Rick Osgood 20 Comments

When you think about the difficulties of working with surface mount components, the first thing that often comes to mind is trying to solder those tiny little parts. Instead of soldering those parts by hand, you can actually apply solder paste to the pads and place all of the components on at once. You can then heat up the entire board so all of the parts are soldered simultaneously. It sounds so much easier! The only problem is you then need a solder stencil. You somehow have to get a thin sheet of material that has a perfectly sized hole where all of your solder pads are. It’s not exactly trivial to cut them out by hand.

[Juan] recently learned a new trick to make cutting solder stencils a less painful process. He uses a laser cutter to cut Mylar sheets into stencils. [Juan] appears to be using EagleCAD and Express PCB. Both tools are available for free to hobbyists. The first step in the process is to export the top and bottom cream layers from your CAD software.

The next step is to shrink the size of the solder pads just a little bit. This is to compensate for the inevitable melting that will be caused by the heat from the laser. Without this step, the pads will likely end up a little bit too big. If your CAD software exports the files as gerbers, [Juan] explains how to re-size the pads using ViewMate. If they are exported as DXF files, he explains how to scale them using AutoCAD. The re-sized file is then exported as a PDF.

[Juan’s] trick is to actually cut two pieces of 7mil Mylar at the same time. The laser must be calibrated to cut all the way through the top sheet, but only part way into the bottom piece. The laser ends up slightly melting the edges of the little cut out squares. These then get stuck to the bottom Mylar sheet. When you are all done cutting, you can simply pull the sheets apart and end up with one perfect solder stencil and one scrap piece. [Juan] used a Full Spectrum 120W laser cutter at Dallas Makerspace. If you happen to have this same machine, he actually included all of the laser settings on his site.

Hacklet #5 – Hackerspaces And DIY Laptops

June 27, 2014 by Adam Fabio 13 Comments

Did you know that Hackaday.io has a hackerspace index? That’s right, you can enter your local hackerspace’s info, pictures, videos, and social media links. Members and crew can link their hackaday.io profiles and drop comments about their latest projects.

The map up at the top of the hackerspace index’s page is interactive too – zoom in on your country and local area to see any spaces nearby. It’s like one-stop shopping for awesome. Well, except that this awesome is free.

It really is great to see all the pictures of spaces large and small. Some of the most stunning shots are from c-base, in Berlin, Germany. Founded in 1995, the c-base crew have created an incredible space. Take a look at the workstation in the photo. Is it Steampunk? Matrix-punk? Heck no, that’s 100% c-base.

Do It Yourself Laptops

You don’t have to be Bunnie Huang to build your own laptop. All it takes is some time, ingenuity,and a good hot glue gun.

Our first laptop is actually inspired by Bunnie’s Novena. The OpenTech-Laptop uses two binders as it’s shell, but inside hides some decent computing power. [OpenTech] used a miniITX motherboard with an ATOM N2800 CPU. The screen came from an old laptop (long live matte 4:3 screens!) [OpenTech] even hand wired a Low Voltage Differential Signaling (LVDS) cable so the motherboard can push those pixels. A wireless keyboard, hard drive, and speakers round out the build. [OpenTech] is still looking for a portable power solution.Why not follow Bunnie’s lead and grab some R/C Plane LiPo batteries, [OpenTech]?

Next up is a MiniBSD laptop computer created by [Jaromir]. MiniBSD is based on RetroBSD, a PIC32 based BSD single board computer. Rather than use a premade platform like the Fubarino, [Jaromir] laid out his own board with everything he wanted – a microSD socket, SDRAM, real-time clock, and all the trimmings. He then added a graphical LCD, a LiPo battery, and a sweet retro keyboard from an old Czech computer company called Tesla. [Jaromir’s] next task is a 3D printed case. The only problem is the case is 2cm wider than his current printer’s bed!

You didn’t think we’d leave the Raspberry Pi out, now did you? Laptop-pi is [Bram’s] project to convert an old DVD player (remember those?) into a Pi Laptop. Not only did [Bram] build a QWERTY keyboard from scratch on perfboard, he also hacked together an on-screen keyboard so he can type with just a D-pad. He’s currently fighting with a dodgy audio amp, but we’re sure that’s just a temporary setback. We think Laptop-pi will be a killer portable for retro gaming!

That’s it for this week’s Hacklet, stay tuned for next week when we bring you more of what’s happening at Hackaday.io!

Astronaut Or Astronot? Nobody Won The Voters’ Lottery (This Week, Anyway)

June 27, 2014 by Brian Benchoff 48 Comments

Yesterday we said we’d be giving away an awesome oscilloscope to a random person on Hackaday Projects if they have voted for their favorite project in The Hackaday Prize. We’re doing one of these a week, and today, at least, nobody won.

We’re going to be doing this every week, so register at Hackaday Projects and vote for your favorite projects entered in The Hackaday Prize. We’ll do this again next week.

Beams Of Light: An Oscilloscope Demo

June 27, 2014 by Adam Fabio 11 Comments

beamsoflight

The demoscene is alive and well, with new demos coming out on a multitude of platforms, including oscilloscopes. Beams of Light is a new demo released at @party in Boston by [TRSi]. Beams isn’t the usual .EXE file format for PC based demos. It’s distributed as a 4 channel wave file. The rear left and right channels are stereo audio. The front channels, however, are vector video to be displayed on an oscilloscope in XY mode.

Beams of Light isn’t the first demo to use an oscilloscope. Youscope and Oscillofun preceded it. Still, you can see [TRSi] pushed the envelope a bit with his creation. He used Processing and Audacity to create the vector video, and his own line tracing algorithm to reduce flyback lines.

[TRSi] included an updated copy of a python based oscilloscope emulator so you can play the demo even if you don’t have the necessary hardware. We wanted to run this the right way, so we powered up our trusty Tektronix 465 and hooked it up to a 1/8″ stereo plug.

Sure enough, the demo played, and it was glorious. We did see a few more retrace lines than the video shows. This could be due to our scope having a higher bandwidth than the 10MHz scope used in the YouTube video. XY demos are one of those rare cases where an analog scope works much better than a low-cost digital scope. Trying the demo on our Rigol ds1052e didn’t yield very good results to say the least. Sometimes good old phosphor just beats an analog to digital converter.

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A SI5351 clock generator chip and an Arduino

Generate Clocks With The SI5351 And An Arduino

June 27, 2014 by Eric Evenchick 10 Comments

If you’re dealing with RF, you’ll probably have the need to generate a variety of clock signals. Fortunately, [Jason] has applied his knowledge to build a SI5351 library for the Arduino and a breakout board for the chip.

The SI5351 is a programmable clock generator. It can output up to eight unique frequencies at 8 kHz to 133 MHz. This makes it a handy tool for building up RF projects. [Jason]’s breakout board provides 3 isolated clock outputs on SMA connectors. A header connects to an Arduino, which provides power and control over I2C.

If you’re looking for an application, [Jason]’s prototype single-sideband radio shows the chip in action. This radio uses two of the SI5351 clocks: one for the VFO and one for the BFO. This reduces the part count, and could make this design quite cheap.

The Arduino library is available on Github, and you can order a SI5351 breakout board from OSHPark.

Building A Wood CNC Router From Scratch

June 27, 2014 by James Hobson 34 Comments

home made cnc router

[David Taylor] needed a CNC router to do some more complex projects — so he did what any maker would do if they’re strapped for cash — make it from scratch!

The impressive part of this build is that it was built entirely in his workshop, using tools he already had. A chop saw, wood lathe, drill and a drill press, and finally a table saw — nothing fancy, but now with the CNC router he has a world of possibilities for projects! The mechanical parts he had to buy cost around $600, which isn’t too bad considering the size of the router. He lucked out though and managed to get the Y-axis and Z-axis track and carriages as free samples — hooray for company handouts!

The router is using an old computer loaded with LinuxCNC which is a great (and free!) software for use with CNC machines. It’s driving a cheap Chinese TB6560 motor controller which does the trick, though [David] wishes he went for something a bit better.

Some examples of the projects he’s already made using this baby include an awesome guitar amp, a wooden Mini-ATX computer case, and even a rather sleek wooden stereo with amp!

Did we mention it can even cut non-ferrous materials?

[via Reddit]

Homebrew Programming With Diodes

June 26, 2014 by Brian Benchoff 18 Comments

diode

Diode matrices were one of the first methods of implementing some sort of read only memory for the very first electronic computers, and even today they can be found buried deep in the IPs of ASICs and other devices that need some form of write-once memory. For the longest time, [Rick] has wanted to build a ROM out of a few hundred diodes, and he’s finally accomplished his goal. Even better, his diode matrix circuit is actually functional: it’s a 64-byte ROM for an Atari 2600 containing an extremely simple demo program.

[Rick] connected a ton of 1N60 diodes along a grid, corresponding to the data and address lines to the 2600’s CPU. At each intersection, the data lines were either unconnected, or tied together with a diode. Pulling an address line high or low ([Rick] hasn’t posted a schematic) pulls the data line to the same voltage if a diode is connected. Repeat this eight times for each byte, and you have possibly the most primitive form of read only memory.

As for the demo [Rick] coded up with diodes? It displays a rainbow of colors with a black rectangle that can be moved across the screen with the joystick. Video below.

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