Can You Use An Easy-Bake Oven For Reflow Soldering?

December 13, 2020 by Kristina Panos 12 Comments

The answer is yes, yes you can. As long as you have one made after about 2011, at least. In the video after the break, [Blitz City DIY] takes us briefly through the history of the venerable Easy-Bake Oven and into the future by reflow soldering a handful of small blinky boards with it.

You’re right, these things once used special light bulbs to cook pint-sized foods, but now they are legit ovens with heating elements that reach 350°F and a little above. The only trouble is that there’s no temperature controller, so you have to use low-temperature solder paste and an oven thermometer to know when to pull the little tray out. Other than that, it looked like smooth sailing.

If you’re only doing a board every once in a while, $40 for a reflow oven isn’t too shabby. And yeah, as with all ovens, once you’ve reflowed a board in it, don’t use it for food.

If you’d rather build an oven, high-powered light bulbs will still do the trick.

Continue reading “Can You Use An Easy-Bake Oven For Reflow Soldering?” →

Putting The Finishing Touches On A 60W Laser

December 11, 2020 by Tom Nardi 26 Comments

At this point if you’re even remotely interested in home laser cutters, you know about the K40. These imported machines are very impressive considering they only cost around $400 USD, but naturally, quite a few corners had to be cut to get the price down. If you’re looking for something with a bit more punch and much higher build quality, a new breed of 60 watt lasers have started popping up on the usual import sites for around $2,000 USD.

While these more expensive machines are certainly much higher quality than the K40, [Jeremy Cook] found there was still plenty of room for improvement. For example, the machine didn’t have any switch cut off the laser when somebody opens the lid. While we don’t doubt some readers will consider this more of a feature than a bug, it’s hard to believe that a tool that costs this much wouldn’t at least offer such a thing as an option.

[Jeremy] also decided to add his own ammeter so he could see how much power the laser is drawing. While not strictly required for day to day operation, it turns out that the controller in many of these machines has a tendency to push the laser tubes beyond their design limits on the higher power settings. With the spec sheet for your tube and a permanent in-line ammeter, you can verify you aren’t unwittingly shortening the life of your new cutter.

Even if you ignore the modifications [Jeremy] makes in his video, it’s still a very illuminating look at what it takes to get one of these lasers ready for operation. Not only do you have to get the thing out of its shipping crate safely, but you need to come up with some way to deal with the fumes produced and get the water cooling system hooked up. It’s a decent amount of work, but the end results certainly look impressive.

While the K40 is still probably the better bet for new players, it’s good to see that there are some viable upgrades for anyone who’s outgrown their entry level machine but isn’t in a position to spend the money on an Epilog.

Continue reading “Putting The Finishing Touches On A 60W Laser” →

Easy Frequency Counter Looks Good, Reads To 6.5 MHz

December 10, 2020 by Al Williams 12 Comments

We were struck by how attractive [mircemk’s] Arduino-based frequency counter looks. It also is a reasonably simple build. It can count up to 6.5 MHz which isn’t that much, but there’s a lot you can do even with that limitation.

The LED display is decidedly retro. Inside a very modern Arduino Nano does most of the work. There is a simple shaping circuit to improve the response to irregular-shaped input waveforms. We’d have probably used a single op-amp as a zero-crossing detector. Admittedly, that’s a bit more complex, but not much more and it should give better results.

Continue reading “Easy Frequency Counter Looks Good, Reads To 6.5 MHz” →

Wireless Quad Voltmeter Brings It All Together

December 10, 2020 by Tom Nardi 4 Comments

If you’re reading Hackaday, you almost certainly have a voltmeter. Matter of fact, we wouldn’t be surprised to hear you had two of them. But what if you needed to monitor four voltage levels at once? Even if you had four meters, getting them all connected and in a convenient enough place where you can see them all at once is no small feat. In that case, it sounds like the multi-channel wireless voltmeter put together by [Alun Morris] is for you.

Built as an exercise in minimalism, this project uses an array of components that most of us already have kicking around the parts bin. For each transmitter you’ll need an ATtiny microcontroller, a nRF24L01+ radio, a small rechargeable battery, and a handful of passive components. On the receiver side, there’s an OLED screen, another nRF radio module, and an Arduino Nano. You could put everything together on scraps of perfboard like [Alun] has, but if you need something a bit more robust for long-term use, this would be a great excuse to create some custom PCBs.

While the hardware itself is pretty simple, [Alun] clearly put a lot of work into the software side. The receiver’s 128 x 32 display is able to show the voltages from four transmitters at once, complete with individual indicators for battery and signal level. When you drill down to a single transmitter, the screen will also display the minimum and maximum values. With the added resolution of the full screen display, you even get a very slick faux LCD font to ogle.

Of course, there are some pretty hard limitations on such a simple system. Each transmitter can only handle positive DC voltages between 0 and 20, and depending on the quality of the components you use and environmental considerations like temperature, the accuracy may drift over time and require recalibration. Still, if you need a way to monitor multiple voltages and potentially even bring that data onto the Internet of Things, this is definitely a project to take a look at.

Continue reading “Wireless Quad Voltmeter Brings It All Together” →

Who Says Solder Paste Stencils Have To Be CNC Cut?

December 9, 2020 by Jenny List 19 Comments

Imagine having a surface mount kit that you’d like to stencil with solder paste and reflow solder, but which doesn’t come with a solder stencil. That was what faced [Honghong Lu], and she rose to the challenge by taking a piece of PET sheet cut from discarded packaging and hand-cutting her own stencil. It’s not a huge kit, the Technologia Incognita 2020 kit, but her home-made stencil still does an effective job.

So how does one create a solder stencil from household waste? In the video we’ve put below the break, she starts with her packaging, and cuts from it a square of PET sheet. It’s 0.24mm thick, which is ideal for the purpose. She then lays it over the PCB and marks all the pads with a marker pen, before cutting or drilling the holes for the pads. The underside is then sanded to remove protruding swarf, and the stencil can then be used in the normal way. She proves it by stenciling the solder paste, hand placing the parts, and reflowing the solder on a hotplate.

It’s clear that this is best suited to smaller numbers of larger components, and we’ll never use it to replace a laser-cut stencil for a thousand tiny 0201 discretes. But that’s not the point here, it’s an interesting technique for those less complex boards, and it’s something that can be tried by anyone who is curious to give stenciling and reflowing a go and who doesn’t have a project with a ready-cut stencil. And for that we like it.

Making your own stencils doesn’t have to include this rather basic method. They can be etched, or even 3D printed.

Continue reading “Who Says Solder Paste Stencils Have To Be CNC Cut?” →

This Automated Wire Prep Machine Cuts And Strips The Wire

December 9, 2020 by Dan Maloney 23 Comments

We’ve seen a fair number of automated wire cutting builds before, and with good reason: cutting lots of wires by hand is repetitive and carries the risk of injury. What’s common to all these automated wire cutters is a comment asking, “Yeah, but can you make it strip too?” As it turns out, yes you can.

The key to making this automated wire cutter and stripper is [Mr Innovative]’s choice of tooling, and accepting a simple compromise. (Video, embedded below.) Using just about the simplest wire strippers around — the kind with a diamond-shaped opening that adjusts to different wire gauges by how far the jaws are closed — makes it so that the tool can both cut and strip, and adapt to different wire sizes. The wire is fed from a spool to a custom attachment sitting atop a stepper motor, which looks very much like an extruder from a 3D-printer. The wire is fed through a stiff plastic tube into the jaws of the cutter. Choosing between cutting and stripping is a matter of aiming the wire for different areas on the cutter’s jaws, which is done with a hobby servo that bends the guide tube. The throw of the cutter is controlled by a stepper motor — partial closure nicks the insulation, while a full stroke cuts the wire off. The video below shows the build and the finished product in action.

Yes, the insulation bits at the end still need to be pinched off, but it’s a lot better than doing the whole job yourself. [Mr Innovative] has a knack for automating tedious manual tasks like this. Check out his label dispenser, a motor rotor maker, and thread bobbin winder.

Continue reading “This Automated Wire Prep Machine Cuts And Strips The Wire” →

A UV Curing Wand For Everyone

December 6, 2020 by Matthew Carlson 12 Comments

The average person’s experience with an ultraviolet (UV) wand is getting a cavity at the dentist. However, anyone with a resin-based 3d printer knows how important a UV curing system is. Often times some spots on a print need a little bit of extra UV to firm up. [Mile] has set out to create an open-source UV curing wand named Photon that is cost-effective and easy to build.

What’s interesting here is that there are dozens if not hundreds of UV curing systems ranging from $5 LED flashlights to larger industrial flood systems. [Mile] dives right in and shows the trade-offs that those cheaper modules are making as well as what the commercial systems are doing that he isn’t. [Mile’s] Photon wand tries to be energy efficient with more irradiated power while staying at a lower cost. This is done by carefully selecting the CSP LEDs instead of traditional wire-bonded and making sure the light source is properly focused and cooled. From the clean PCB and slick case, it is quite clear that [Mile] has gone the extra step to make this production-friendly. Since there are two industry-standard wavelengths that resins cure at (364nm and 405nm), the LED modules in Photon are user-replaceable.

What we love about this project is looking past what is readily available and diving deep. First understanding the drawbacks and limitations of what is there, then setting a goal and pushing through to something different. This isn’t the first UV curing tool we’ve seen recently, so it seems there is a clear need for something better that’s what is out there today.

Continue reading “A UV Curing Wand For Everyone” →