Homemade reflow ovens are a great inexpensive way to quickly solder multiple prototypes at once. [Andy] may just have built one of the best ones we’ve featured so far on Hackaday. For his project a £25 1300W 12litre halogen oven was chosen because of its low cost and fast heating time, the latter being required to follow typical reflow profile ramp-up stages.
To control the AC power [Andy] first bought a chinese Fotek Solid State Relay (SSR) on ebay, which was quickly replaced by an american one after reading concerning reports on the internet. He then made the same ‘mistake’ by buying the typical MAX6675 thermocouple-to-digital converter from the same website, as he spent much time understanding why the measurements were wrong when the IC was just defective. His final build is based around a 640×360 TFT LCD that he previously reverse engineered, the cortex-M0 STM32F051C8T7, a SPI flash, some power regulators and buttons. The firmware was written in C++ and we’ll let our readers visit [Andy]’s page to see how well his oven performs.
Need to do some SMD soldering? No tools? No problem! Here’s a creative method that could be a handy tool to add to your belt: SMD soldering using hot sand.
[Oliver Krohn] recently released this little video demonstrating how to perform re-flow soldering using hot sand. He’s using a bunsen burner to heat up a ceramic pot of sand to use as a kind of hot plate. It seems to work pretty well, and it’s a very unique way of doing it — if you wanted to get a bit more technical, you could also throw a temperature probe in the sand to get a much finer heat control!
Of course there are lots of other ways of doing re-flow soldering, like using a re-purposed toaster oven, frying up some circuits on a skillet after you’ve had your bacon, or if you want to be fancy, you could even build your own toolkit for it!
Anyway, stick around for the epic video of SMD soldering on hot sand.
Continue reading “SMD Soldering on… Hot Sand?”
Has reflowing surface mount components got you down? [Giorgos] is currently working on a project that will lift your spirits…. well at least your hot air gun. Tired of manually holding his heat gun in one hand and IR thermometer in the other, [Giorgos] set out to create a device to alleviate just that. Although not completed yet, it appears the machine’s intent is to hold the heat gun at an appropriate height above the work piece in order to achieve the correct reflow temperature. He doesn’t say how the height of the hot air gun will be controlled. We’d like to see a microcontroller adjust the height of the hot air gun depending on the temperature of the component to be reflowed. [Giorgos] gives an extremely detailed account of his build process. Make sure to check out all four pages of the project post!
We’ve seen a lot of interesting work from [Giorgos] over the years like this capacitive touch-pad entry system.
[via Dangerous Prototypes]
[Tyson’s] family went with creating rather than buying Christmas presents last month, which gave him the opportunity to build some electronic fireflies for gifts. He drew inspiration from a similar firefly project we featured last year, but expanded on the original model by designing dedicated PCBs and housings for each of his firefly pieces.
Although he’d settled on using ATTiny85’s for this project, [Tyson] was fresh out of through-hole versions. He decided to skip the prototyping phase and go right for fabrication, cranking up the laser-jet printer for some toner-transfer, which successfully produced 4 functioning boards (and 3 failures). The fireflies were [Tyson’s] first attempt at SMD soldering, and we’d have to say it’s a job well done; he reflowed each board with a cheap-o heatgun from Harbor Freight.
After some hiccups with fuse programming, [Tyson] got the code uploaded and the fireflies illuminated. Swing by his site for the nuts and bolts on construction, then snag the project files here. (Direct .zip download)
[Kyle] teaches photography and after being dismayed at the shuttering of film and darkroom programs at schools the world over decided to create a resource for film photography. There’s a lot of cool stuff on here like mixing up a batch of Rodinal developer with Tylenol, lye, and sodium sulphite, and assessing flea market film cameras. There are more tutorials coming that will include setting up a dark room, developing prints, and playing around with large format cameras.
[hifatpeople] built a binary calculator out of LEGO® bricks or toys. It started off as a series of logic gates built out of LEGO® bricks or toys in the LEGO® Digital Designer. These logic gates were combined into half adders, the half adders combined into full adders, and the full adders combined into a huge plastic calculator. Unfortunately, buying the LEGO® bricks or toys necessary to turn this digital design into a physical model would cost about $1000 using the LEGO® Pick-A-Brick service. Does anyone have a ton of LEGO® Technic® bricks or toys sitting around? We’d love to see this built.
Think you need a PID controller and fancy electronics to do reflow soldering in a toaster oven? Not so, it seems. [Sivan] is just using a meter with a thermocouple, a kitchen timer, and a little bit of patience to reflow solder very easily.
The folks at DreamSourceLabs realized a lot of electronic test equipment – from oscilloscopes and logic analyzers to protocol and RF analyzers were all included a sampling circuit. They designed the DSLogic that puts a sampler and USB plug on one board, with a whole bunch of different tools connected to a pin header. It’s a pretty cool idea for a modular approach to test equipment.
Adafruit just released an iDevice game. It’s a resistor color code game and much more educational than Candy Crush. With a $0.99 coupon for the Adafruit store, it’s effectively free if you’re buying anything at Adafruit anytime soon. Check out the video and the awesome adorable component “muppets”.
Still looking for a good way to reflow solder at home? Look no further! [Don] has a very handy and inexpensive solution that looks great. It makes use of a cheap hot plate, a solid state relay, an IR temperature sensor, and an arduino.
[Don] started by modifying the hotplate by reversing the handle mount — this provides a useful location to mount the IR temperature sensor. The control circuit uses PWM to adjust the temperature of the hot plate using the solid state relay. Because the IR temperature sensor has a cone of visibility it ends up reading an average area temperature as opposed to an individual point — for reflow soldering this is perfect. [Don] notes that some calibration is required, as depending on the emissivity of the object being measured the readout can differ — shiney objects will read a lower temperature than dark objects. He recommends doing the calibration with a scrap PCB and your chosen solder paste to get a general baseline for your project.
Need more info on the actual reflow process? We posted a handy guide a few months ago.