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19 November 2011

What are the tools needed for a complete electronics workbench?

DIY Essentials

Does your do-it-yourself workbench have everything you need?

By James Turner  /  August 2011

photo of workbench
All Photos: Randi Silberman Klett
Click on image for enlargement.
 
What are the tools every hands-on projecteer needs? To answer that question, we went right to DIYers themselves, specifically the exhibitors at last fall's World Maker Faire NY event.

multimeter
One tool everyone agreed on is a Multimeter. It's surprising how much information you can glean from a simple resistance reading or by checking out the voltage drop across a series of LEDs. Basic analog meters start at around US $15, but consider getting one with a digital display and an audible continuity tester. When you're up to your arms inside a chassis probing a pair of contacts, you don't want to keep looking away just to see if you have continuity between two points. You'll also want a variety of ends for the probes, such as alligator clips and PC board lead hooks.

soldering iron and group photos
Next you'll want a Soldering Iron. Some of the Maker Faire geeks didn't look for much more than the simple ones that cost less than $10, but others wanted the flexibility that a digitally controlled soldering station brings ($80; more for a name brand such as Weller). With advanced projects, you may need to vary the iron temperature depending on your components.

Sometimes, though, you just need a lot of heat, especially when soldering a large component or a thick wire. A conventional iron can't heat a large mass of metal quickly enough. Casey Haskell of Sparkfun Electronics likes to have a propane-powered pen iron for its portability, while others prefer a high-watt soldering gun.

Some of the Makers have moved beyond "through-hole" PC boards and now like to work with surface-mount devices. The "right" way to reflow solder for SMDs is using a purpose-made oven, but many a brave adventurer has gotten by with a toaster oven and some TLC. You can also use a hot-air gun or a hot-air pencil, which lets you do SMD one component at a time. Justin Huynh, who hacks remote-controlled cars with Arduinos, the popular DIY microcontrollers, uses this technique as well as a variable-temperature Weller. "I've always used the Wellers," he says. "My friends who are engineers use them. They just work really well."

Along with an iron, you'll want to have a way to desolder, for those inevitable missteps. Some people like to use desoldering braid; others like Desoldering Irons with suction bulbs. I've used both, and I find the irons do a better job with less heating of the components.

Most of us start out using batteries or cannibalizing power adapters, but a good bench Power Supply lets you control voltages precisely as well as measure and limit the amperage flowing through the circuit. You can get a reasonable single-voltage supply for $120 or so, such as the 18-volt, 3-ampere supply made by Extech Instruments. More advanced ones will offer multiple controllable voltages, useful when projects have more than one input voltage.

A bench supply goes well with a large Protoboard, one that supports multiple supply voltages and has lots of real estate to lay out chips. If you do a quick proof of concept on a protoboard first, you can save yourself a lot of grief when you try to set out a permanent version (or send it out to a printed-circuit-board fab).
bench supply and group photos
Haskell notes that no good workbench should be without a few nonelectrical items as well, such as Calipers. "I use them constantly," he says. They're especially critical when you start to lay out circuits in close quarters, such as inside an enclosure. Another go-to item is a good hot Glue Gun. This is not to be confused with a craft glue gun, which uses low-temperature glue sticks. An industrial gun melts at a much higher temperature, and the material is nearly as hard as plastic when it cools. Haskell has another nontraditional tool in his bag of tricks. "A bag of LEDs is really helpful," he says. "It's a good way to see if something is getting power."

So far, we've been talking about items that you can get for around $100. Of the Makers I spoke to who could afford one, the next tool they went for was an Oscilloscope. A good one, such as a 40-megahertz Tektronix, can cost $950, and the prices rise quickly from there. Huynh says that his group had to pool their money to afford even a used one, a common strategy for hobbyists.

There's one other big-ticket item most makers yearn for. "We'd love to have a Logic Analyzer for working with chips," says Huynh, "but it's kind of pricey." A good one (better than the portable unit shown here) is invaluable, especially if you need to look at several seconds of history.

Haskell says that if money were no option, his next purchase would be either a desktop computer numerical control machine or a 3-D Printer. As it turns out, desktop CNC machines are coming down in price quickly; there are designs available for under $500 at this point. And 3-D printers are selling for less as well, some piggybacking on top of the new CNC platforms.

The nice thing about getting a workbench together is that you can do it gradually. That's why it's often worth spending a bit more to get the item you really want. There's nothing worse than having to buy something better six months down the road. Shop with care, consider used equipment, and before you know it, you'll be ready to tackle just about any project you can imagine.

About the Author

James Turner is a contributing editor for O’Reilly Media, a correspondent for the Christian Science Monitor, and a regular contributor to IEEE Spectrum. Next month he’ll describe how to build a high-quality, low-cost oscilloscope using an iPad.

To Probe Further

For the back story about IEEE Spectrum photo editor Randi Silberman Klett being scanned in 3-D, see the sidebar, "A 3-D Me."

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