About Windell

Co-founder of Evil Mad Scientist Laboratories.

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

Introducing the EggBot Pro

EggBot Pro

An EggBot is a compact, easy to use art robot that can draw on small spherical and egg-shaped objects. The EggBot was originally invented by motion control artist Bruce Shapiro in 1990. Since then, EggBots have been used as educational and artistic pieces in museums and workshops. We have been working with Bruce since 2010 to design and manufacture EggBot kits, and our well-known Deluxe EggBot kit is a popular favorite at makerspaces and hackerspaces around the world.

Today we’re very proud to release the newest member of the family: the EggBot Pro, a near-complete reimagining of the EggBot, designed for rigidity, ease of use, and faster setup.

EggBot Pro

The EggBot Pro is as sturdy as can be: Its major components are all solid aluminum, CNC machined in the USA, and powder coated or anodized. (And isn’t it a beauty?)

The most common mechanical adjustments are faster with twin bicycle-style quick releases, and repositioned thumbscrews for easier access.

EggBot Pro

The frame also has an open front design that gives much better visibility while running, and greatly improved manual access when setting up.

EggBot Pro

And, it comes built, tested, and ready to use — no assembly required.  Assuming that you’ve installed the software first, you can be up and printing within minutes of opening the box.

The EggBot Pro begins shipping this week. We’ve also put together a little comparison chart, so you can see how it fits in with the rest of the family.

 

New Winches for WaterColorBot

We’ve just given the WaterColorBot a little bump up to kit version 1.5. The new version now comes with a pair of beautifully machined aluminum winches.

The winches are precision cut on CNC machines and anodized clear. We add a few extra little parts (flat-head rivets to wind the winch around, screws, and a stamped and polished stainless steel “clamp” to hold the string end), and wind them with the same “100 pound” Spectra cord as we did before.

We described the process of making and winding our older laser-cut wooden winches in our blog post about the making of the WaterColorBot, and again in our post about the  winch cutting jig. For better or worse, transitioning to the new aluminum means that we’re no longer using our older wooden winches that we described in those blog posts.  But in the end, these new winches are a better, more elegant solution.

 WaterColorBot kit version 1.5 is now shipping from the Evil Mad Scientist Shop.

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.

Linkdump: July 2014

Comet 67P/Churyumov–Gerasimenko nucleus

A Fragment of Muonionalusta

meteorite 5

This little chunk of crystalline metal is a tiny slice of a meteorite — a rock that fell from the sky. When one says that, the next natural question is, “how do you know it’s a meteorite?” (We will get to that.) But what is really staggering is not just that we know, but how much we know about it and its history. And what a long history it is.

This specimen is a 68 gram sample cut from a fragment of the Muonionalusta meteorite.  According to our best current understanding, the parent body that Muonionalusta came from was one of the earliest bodies to take shape during the formation of our solar system. It began as a protoplanet (or planetisimal) that accreted within the protoplanetary disk that would eventually become our solar system. It accreted over the course of roughly the first million years after the beginning or our solar system. (That is to say, during the first million years after the very first solids condensed from the protoplanetary disk.) The parent body had an iron-nickel “planetary” core, 50–110 km in radius, that was eventually exposed by collisions that stripped away most of its insulating mantle. It cooled very slowly over the next 1-2 million years. It is estimated (with startling precision) by Pb-Pb dating that the body crossed below a temperature of ~300 °C at 4565.3 ± 0.1 million years ago, just 2-3 million years after the solar system began to form. For the next four billion years, it led a largely unremarkable existence as an asteroid (minor planet) until it broke apart (possibly due to a major collision) about 400 million years ago. Then, one fine day roughly one million years ago, a large fragment entered the earth’s atmosphere, breaking into hundreds (perhaps, thousands) of smaller fragments that rained down in a shower of fire upon what is now northern Sweden and Finland. Four ice ages transported the surviving meteorite fragments across the Swedish tundra, until their first discovery (and naming after the nearby Muonio river) in 1906.

But, how do we know all of that?
Continue reading

Electro-Kistka: Dyeing an Egg in Place?

Kistka-brush 11

In our annoucement article about the EggBot Electro-Kistka — the hot wax dispenser for the EggBot — we noted that it can be challenging to reposition an egg after taking it out to dye the egg between wax layers.

As an alternative suggestion, reader Dan commented:

Could you leave the egg in the EggBot and paint on the first layer(s) of dye with a brush? Then dip the egg for the last layer to get the ends covered.

Well, let’s try and see how it turns out!

Continue reading