Solderless Flickery Flame

We’ve talked previously about making simple LED pumpkins with candle flicker LEDs. Lately we’ve been playing with making better looking flames by using multiple independent flickering LEDs with different colors and lens styles. It makes a spectacular difference: it goes from something that looks like, well, a flickering LED to something that really looks like there might be a flame in there.

The end result is pretty neat: A compact battery powered “flameless flame” that looks great in a pumpkin, luminaria, or as a stage prop. The interplay of the different LED types and colors gives an ever-changing and shifting flame display.

Other than the candle flickering LEDs, the parts are commonly available. We’ve also bundled them together in the Solderless Flickery Flame Kit.

Components:

  • Battery Holder (2×AA with switch)
  • Mini-breadboard
  • 6 × candle flicker LEDs (2 red diffused, 2 yellow diffused, and 2 yellow clear lens)
  • 6 × 68 ohm resistor
  • 2 × wire jumper
  • White paper bag (optional)

Also needed:

  • 2 × AA Batteries (not optional)
  • Wire clippers, cutting pliers, or “beater” scissors (optional)

Hook up the battery holder to the breadboard several rows apart to give enough room to install the resistors and LEDs. Optional: peel off the backing on breadboard and adhere it to the battery holder. Connect each LED with its own 68 ohm resistor. (Use the “in parallel” method from this article.) The extra jumpers are included to help bridge across the center gap in the breadboard.

Trimming the resistor leads will keep the breadboard tidy, and help prevent short circuits. Trimming the LED leads to varying heights will help distribute the light in different ways.

The white paper bag included with the kit can be used for creating a traditional luminaria or for making a ghostly halloween decoration.


You can find more Halloween decor projects in our Halloween Project Archive.

Fixing on the fly at Maker Faire

Maker Faire can be a pretty demanding environment for a project. Outdoor locations expose many projects to the weather, prototypes may have been unpacked and repacked by the TSA, and curious visitors may handle projects in new and unexpected ways. Or maybe ambitions were greater than preparation time, and the project just didn’t quite get finished before the fair opened. No matter what the reason, Maker Faire is a great place to see people in action fixing, troubleshooting, and finishing their projects. Below are some beautiful projects I caught in progress at Maker Faire New York.

Pick n place

The FirePick Delta pick and place machine was a victim of the TSA, and arrived less functional than when it had been packed. The team was working on it valiantly, which also provided opportunities to get a closer look at many of the components.

Pick n place

Components not in use were repurposed for holding down business cards in the breezy aisle of 3D village.

Fixing robotic soccer

The maker of this robot arm soccer game was opening up one of the control boxes to check on a malfunctioning knob.

Robotic soccer (after repair)

He had no shortage of willing testers after the repair.

Tiny 3D printer under repair

This half-scale 3D printer assembly was at least as charming in its disassembled state as it would have been all put together. It is great to see the components along with the kinds of tools that are used to assemble and repair projects like this one.

Gertie the jumping robot

Gertie the robot had seen quite a bit of action, first at the Bay Area Maker Faire and then in New York. Her actuators were apart and in the middle of repair when we came by.

Gertie the jumping robot

This let Alonso show us the mechanism and demonstrate how the internal frame worked to lean and make Gertie jump in different directions.

Maker Faire exhibitors are generous with sharing tools and materials with each other, and visitors are treated to what are typically hidden activities. No one whisks away a broken prototype to hide it out of sight. Instead, the guts are happily spilled out for everyone to see and learn from.

Soldering Tip Tinning with Sal Ammoniac


If you solder, you’ve likely come across an “untinned” tip at some point— that’s when the tip of your soldering iron loses its shine, and doesn’t easily wet to solder any more.

Once your tip gets this way, it doesn’t make nearly as good of a thermal contact to whatever you are trying to solder, and it simply doesn’t work well. Soldering can take 2-10 times as long, and that isn’t good for your circuit board, components, or mental health.

You can sometimes re-tin the tip by melting fresh solder onto it, but that can be challenging, because the whole problem is that the tip isn’t melting solder. It’s particularly hard to keep tips tinned with modern lead-free solder, because it needs to get even hotter to begin melting.  If you get to this point, you might think about even replacing the tip.

But before you throw that tip away, instead consider using one of the “old standard” solutions, which is to refurbish the tip with a tip-tinning compound. And we came across the most classic of them in one of the most unexpected locations.  Continue reading

From the mailbag: Bulbdial Clock Kit

Bruce B. wrote in to say:

I recently bought one of your Bulbdial clock kits. I just wanted to send a quick note to say that your step-by-step guide was the BEST guide I have ever seen, for anything. I have assembled many an item in my years and instruction sets vary from useless to marginally worthwhile. The Bulbdial guide was amazing! You should publish a step-by-step guide on how to write step-by-step guides :)
Oh, and the clock is amazing as well!

The XL741 Discrete Operational Amplifier

Ever since we released our Three Fives discrete 555 timer kit last year, people have been asking us “When are you going to come out with a 741 op-amp?” It has taken us quite a while to get here, but the answer is… Today!

Our XL741 Discrete Operational Amplifier is a real, working op-amp that you can build yourself.  It’s a transistor-scale version of the original μA741 integrated circuit, that incredibly versatile and popular analog workhorse. As with our 555 kit, you can probe inside to see the inner workings of the circuit as it works. And, like our 555, it comes with a beautiful anodized aluminum “IC legs” stand, so it even looks great when it isn’t plugged in.

The kit was designed and developed as a collaboration with Eric Schlaepfer, and is a direct adaptation of the equivalent schematic from the original Fairchild μA741 datasheet.

If you’ve ever used operational amplifiers, you’re probably familiar with the μA741 (or colloquially, just “the 741″). Designed by Dave Fullagar and released by Fairchild in 1968, it’s the quintessential and most popular op-amp of all time. While newer op-amp designs easily outperform the μA741 in just about every possible respect (speed, noise, voltage range, and so on), the 741 remains widely beloved and in active production by multiple manufacturers even today — over 45 years later.

And, if you haven’t used an op-amp, this a great way to learn. Op-amps are simple, wonderful building blocks for making analog computers. With op-amps, you can build circuits that can (for example) add, subtract, amplify, take logarithms, perform integration, or perform other operations on your signals. Or buffer and copy them, or cleanly convert current to or from voltage, and on and on and on.

A regular op-amp is an integrated circuit; a little black box. The XL741, on the other hand, is a big black box, with a heck of a lot of points where you can can probe inside, to see what’s going on, in real time. And that’s a unique opportunity.

The XL741 is a quick, easy to build soldering kit, with through-hole components, and not too many of them. (And, have you see our awesome resistor wallets?)

And, best of all, the XL741 is in stock, and begins shipping today. 

Visit our store page for links to the XL741 datasheet, assembly instructions, and additional documentation resources.

From the mailbag: Fun soldering

Eric wrote in to say:

It was fun. It was fun to build the Larson Scanner. It was fun because I successfully put it together and it worked as designed. It was so fun I’ll do this again!

In the mid 70′s I attempted to construct a Radio Shack short wave radio kit with a soldering gun. That’s right, I used a soldering gun. Believe it or not, it worked … as a battery heater upper.

Thank you for the helpful instructions and well designed kit. It’s nice to know that 40 years after my last kit, I can drop the battery killer nickname.

LED Robot Sign

Krummrey shared an LED Robot Sign tutorial on Instructables using one of our original Peggy boards. (Peggy 2 would work for this, too.)

I don’t solder the LEDs in. That way I can just pull them back out and make a new sign when I get tired of the current one.

That big pile of LEDs looks like so much fun! He also posted some more sign designs at the end of the instructable.

Ingenious 1970′s Technology: The Flip Flash

FlipFlash 5

Once upon a time, cameras did not come with LED illumination or even xenon strobes, but rather with a socket that could fire a one-time-use flashbulb.

An advance from this was the “flip flash” cartridge which held 8 or 10 flash bulbs, ganged up so that you could take one photo after another, without pausing to swap bulbs. Each time that you took a picture (exposing actual film!), the next flashbulb in the cartridge would fire.

But you might ask a tricky question here: How does it know which bulb to fire next?

Continue reading

3D LED POV Mirror

“We Are with You, Mirror” is a piece by Brady Marks from VIVO Media Arts Centre that was shown at the Vancouver Mini Maker Faire. It is a 3D persistence of vision volumetric display that acts as a mirror, using four spinning Peggy 2 boards to reflect visitors movements in low resolution 3D LED glory.

Thank you to Brady for sending in the video!