Exhaust Fan-Equipped Reflow Oven Cools PCBs Quickly

December 3, 2020 by Dan Maloney 6 Comments

With reflow soldering, sometimes close is good enough. At the end of the day, the home gamer really just needs a hot plate or an old toaster oven and a calibrated Mark I eyeball to get decent results. This exhaust fan-equipped reflow oven is an attempt to take control of what’s perhaps the more challenging part of the reflow thermal cycle — the cool down.

No fan of the seat-of-the-pants school of reflow soldering, [Nabil Tewolde] started with a cast-off toaster oven for what was hoped to be a more precise reflow oven. The requisite temperature sensors and solid-state relays were added, along with a Raspberry Pi Zero W and a small LCD display. Adding the cooling assist started by cutting a gaping hole cut in the rear wall of the oven, which was then filled with a short stretch of HVAC duct and a stepper-controlled damper. The far end of the duct was fitted with a PC cooling fan; while it seems sketchy to use a plastic fan to eject hot air from the oven, [Nabil] says the exhaust isn’t really that hot by the time it gets to the fan. At the end of the reflow phase of the thermal profile, the damper opens and the fan kicks on, rapidly cooling the oven’s interior.

Unfortunately, [Nabil] still needs to crack open the oven door to get decent airflow; seems like another damper to admit fresh air would help with that. That would complicate things a bit, but it still wouldn’t be as over-the-top as some reflow builds we’ve seen. Then again, that calibrated eyeball thing can work pretty well too, even without a toaster oven.

Continue reading “Exhaust Fan-Equipped Reflow Oven Cools PCBs Quickly” →

SMD Challenge Extreme Edition Gets Our Flux Flowing

November 25, 2020 by Kerry Scharfglass 15 Comments

Skills challenges have become a fun way to facilitate friendly competition amongst anyone who appreciates a fine solder joint. If you’ve seen any Supercon / Remoticon coverage there’s surely been a mention of the infamous soldering skills challenge, where competitors test their mettle against surface mount components sized to be challenging but fair. What if there was a less friendly SMD challenge designed to make you hold your breath lest you blow the components away? Well now there is, the SMD Challenge Extreme Edition by friend-of-the-Hackaday and winner of the 2019 Supercon soldering challenge [Freddie].

When assembled the SMD Extreme Edition uses a 555 timer and a 74HC4017 decade counter to light a ring of 10 LEDs lights around its perimeter, powered by a coin cell. However the Extreme Edition deviates from the typical SMD Challenge format. Instead of ramping up in difficulty with ever-shrinking components, the Extreme Edition only has one size: torturous. See those gray blobs in the title image? Those are grains of rice.

The Extreme Edition’s 0201-sized LEDs aren’t the absolute smallest components around, but to minimize enjoyment all passives are 01005. (Check out the SMD Challange Misery Edition for even 01005 LED action.)

The Extreme Edition has other tricks up its sleeve, too. That 555 may be venerable in age, but this version is in an iron-frustrating 1.41 x 1.43 mm BGA package, which pairs nicely with that decade counter in 2.5 mm x 3.5 mm QFN.

Despite the wordwide pandemic locking down travel and conferences, a few brave challengers have already taken up their iron and succeeded at Extreme SMD. Want to see it in action? Check out the original Tweets after the break.

Continue reading “SMD Challenge Extreme Edition Gets Our Flux Flowing” →

Robotics Club Teaches Soldering

November 13, 2020 by Al Williams 25 Comments

Oregon State University must be a pretty good place to go to school if you want to hack on robots. Their robotics club, which looks active and impressive, has a multi-part video series on how to solder surface mount components that is worth watching. [Anthony] is the team lead for their Mars Rover team and he does the job with some pretty standard-looking tools.

The soldering station in use is a sub-$100 Aoyue with both a regular iron and hot air. There’s also a cheap USB microscope that looks like it has a screen, but is covered in blue tape to hold it to an optical microscope. So no exotic tools that you’d need a university affiliation to match.

Continue reading “Robotics Club Teaches Soldering” →

SMD Breadboard Adaptors Skip Schematic, Goes Straight To PCB

October 17, 2020 by Chris Lott 23 Comments

If you need to add one or two SMT chips to your breadboarded prototype, [Travis Hein] has you covered. He designed a set of small SMD adaptor boards for various SOIC, SOT23, and DPAC patterns using KiCad. He has released them as open source, so you can feel free to use them or modify them as needed.

Normally we don’t see people bypassing the schematics when designing a PCB. But we can agree that [Travis] has found a situation where going direct to PCB makes more sense. He just plops down the package in Pcbnew, adds some pin headers and wires everything up directly on the PCB. (But don’t worry, some of you may remember [Travis] from his earlier SSR mains switching project, which demonstrates that he can indeed draw proper schematics.) We know there are more people out there who prefer to go straight to PCB layout… [mikeselectricstuff] comes to mind. If you could yourself among this tribe, let use know your reasoning in the comments below.

We wrote about a similar universal breakout boards for SMD parts back in 2016, which is a single breakout board for two- and three-pin jelly-bean components. If you paired some of those boards with [Travis]’s breakout boards, it would make a great combination to keep in your prototyping gadgets bin. Consider this project the next time your favorite PCB shop has a sale.

Spare SMD Storage, With Stacking SMT Tape Reels

October 5, 2020 by Donald Papp 10 Comments

[Kadah]’s solution for storing short tapes of SMT parts is as attractive as it is clever. The small 3D-printed “tape reels” can double as dispensers, and stack nicely onto each other thanks to the sockets for magnets. The units come in a few different sizes, but are designed to stack in a consistent way.

We love the little touches such as recessed areas for labels, and the fact that the parts can print without supports (there are a couple of unsupported bridges, but they should work out fine.) Also, the outer dimensions of the units are not an accident. They have been specifically chosen to nestle snugly into the kind of part drawers that are a nearly ubiquitous feature of every hardware hacker’s work bench.

STLs are provided for handy download but [Kadah] also provides the original Fusion 360 design file, with all sizes defined as easily-customized parameters. In addition, [Kadah] thoughtfully provided each model in STEP format as well, making it easy to import and modify in almost any 3D CAD program.

Providing 3D models in STEP format alongside STLs is nice to see, because it gives more options to people if things need some tweaking, because editing the STL file can be done if needed, but isn’t optimal. Thankfully the ability to export STEP files is still open to hobbyists using Fusion 360, since Autodesk decided to leave that feature available to personal use licenses.

Building A Compact Reflow Oven With Halogen Lamps

September 25, 2020 by Lewin Day 7 Comments

Very often, particularly on the Internet, we’re fooled into thinking bigger is always better. The fact remains that this isn’t always the case. When it comes to reflow ovens, for example if you’re working with short runs of small PCBs, or if you just don’t have a lot of space in the workshop, a smaller oven will be more desirable than a large one. It’s factors like these that drove [Sergi Martínez]’s latest build.

Built inside a metal project case, first attempts involved using an off-the-shelf heating element, with poor results. The element had a high thermal inertia, and was designed for use in water, so didn’t last in the reflow application. Learning from the experience of others, [Sergi] switched to using halogen lamps, netting much greater success. An Arduino Nano is responsible for running the show, using firmware developed by [0xPIT]. There’s also a screen for monitoring reflow profiles, and a cooling fan to help keep temperature in the ideal zone.

It’s a tidy build that would be particularly useful for quickly running batches of small PCBs without the long wait times required to heat a larger oven. Energy efficiency should be better, too. Of course, if you’re a fan of the classic toaster oven builds, we’ve got those too. Video after the break.

Continue reading “Building A Compact Reflow Oven With Halogen Lamps” →

This Four-Axis Stencil Printer Is The Ultimate In SMD Alignment Tools

July 26, 2020 by Dan Maloney 7 Comments

Here at Hackaday we love all kinds of builds, and we celebrate anytime anyone puts parts together into something else. And while we love the quick and dirty builds, there’s just something about the fit and finish of this four-axis SMD stencil printer that really pushes our buttons.

This build comes to us from [Phillip], who like many surface-mount users was sick of the various tape-and-PCB methods that are commonly used to align the solder stencil with the PCB traces. His solution is this fully adjustable stencil holder made from aluminum extrusions joined by 3D-printed parts. The flip-up frame of the device has a pair of clamps for securely holding the stainless steel stencil. Springs on the clamp guide rods provide some preload to keep the stencil taut as well as protection from overtensioning.

The stencil can move in the X-, Y-, and Z-axes to line up with a PCB held with 3D-printed standoffs on a bed below the top frame. The bed itself rotates slightly to overcome any skew in alignment of the PCB. [Phillip] was aghast at the price of an off-the-shelf slew-ring bearing for that axis, but luckily was able to print up some parts and just use simple roller bearing to do the same thing for a fraction of the cost. The frame is shown in use below; the moment when the pads line up perfectly through the stencil holds is oddly satisfying.

This puts us in mind of a recent, similar stencil printer we covered. That one was far simpler, but either one of these beats the expedient alignment methods hands down.

Continue reading “This Four-Axis Stencil Printer Is The Ultimate In SMD Alignment Tools” →