In the 26 months that I’ve been working at Popular Woodworking, we’ve studied and discussed drills in most ways imaginable. We’ve examined batteries moving from 12 volts through 18 volts and even up to 36 volts in power. (Now we’re moving back down the scale to see manufacturers develop 10.8-volt drill/drivers and even a handful of tools with 4-volt or lower batteries.)

And we’ve traversed the chasm from Nickel-cadmium to Lithium-ion batteries. We’ve even divided Lithium batteries into a number of sub-categories. So what’s next?

Torque! That’s the next measurement manufacturers want us to use to decide which drill/driver to purchase. Is this something meaningful to woodworkers? I can see torque being important when you drive 3" screws into a deck, but when I use my drill under normal circumstances, I cannot see where one tool with more measurable torque is better. But, I don’t adjust my drill torque. I tend to leave the setting at the "drill" mode and simply release the trigger when the screw is set to my required depth. I do, however, have to agree that providing a given measurement that would allow us to directly compare apples to apples – or drill to drills in this case – is a good idea.

To that end, most manufacturers have agreed upon a set of accepted guidelines to measure torque. These guidelines are set forth by the Power Tool Institute (PTI) – to which most major tool manufacturers belong. (Click here for a list of members.) This method for measuring relative output torque does not apply to hammer drills, rotary drills and impact drivers.

The Relative Torque Measurement (RTM) is reported to a 95 percent degree of confidence. The test is made on five normal production samples that have not been modified, and each sample is tested five times with a minimum three-minute cool down between tests. This, according to PTI, ensures more consistent readings.

Cordless tools use the same battery for all five trials without recharging. A properly conditioned battery –in PTI terms, a battery that consists of five charges and discharges completed on the supplied battery charger – is used.

Corded tools are tested with a regulated power supply circuit that matches the voltage and frequency numbers on the tool’s nameplate.

All tools will be supported in a torque fixture (See the PDF below) to prevent any movement from applied torque and if there’s a clutch on the drill/driver, that clutch is set to a full-lock position. (If the tool slips, the test results are considered invalid and will be repeated.) If the tool has changeable gears, it will be tested in the gear that results in the greatest torque.

The results of the 25 tests are tabulated and put through a number of mathematical calculations to find the "Lower 95% Confidence Limit" and the "Upper Confidence Limit." The rating released falls somewhere within these two boundaries.

If you would like to read the exact process for yourself, open the PDF below.

First to adopt and publish results from these tests is Makita. On the company’s web site, a couple of Makita drill/drivers have the torque numbers listed.

Any comments?

—Glen D. Huey

Torque Fixture.pdf (347.12 KB)

PTI Test.pdf (308.26 KB)

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While pegging the joints in a Shaker stepback I built for the February 2009 issue of Popular Woodworking (which mails to subscribers at the end of December), I used a $100 flush-cut saw. It’s a darn nice saw. Unless one clogs the teeth with glue.

Now, I didn’t intend to make it look as if I were trying to cover up my crime. I meant to ask Editor Christopher Schwarz how best to clean the yellow glue out of its tiny little teeth. But he was out that day, I got distracted with other stuff, and the saw ended up back in the rack, gunk and all.

About two weeks later, it was summarily brought to my attention that this pricey saw was now unusable. But Chris suggested a solution (short of buying a new saw), and it worked. I poured white vinegar into a shallow Pyrex pan and soaked the gunked-up teeth for a half-hour or so, then I went to work with an old toothbrush. It took some serious scrubbing, but the vinegar softened the dried glue enough to allow me to scrub it out, tooth by tooth. To speed up the process, you could heat the vinegar in a microwave, but that would increase the aroma. (After a visit from our human resources department during the last time we sprayed a finish, well, we try to avoid stinky things as much as possible.) 

After the teeth were cleaned, I rinsed the vinegar away and wiped the blade with jojoba oil. The blade lost some of its shiny luster, but the teeth cut, and that's $100 I can spend on shoes. Or on a couple new Hock plane blades.

— Megan Fitzpatrick, managing editor

If a decade ago you lived in the Cincinnati area, you likely attended the F+W Warehouse sale. At the time, we had a book warehouse on our Evanston property (the old Coca Cola bottling plant), and every year we sold returns, remainders and overstock books at rock-bottom prices. It's been almost 10 years since we had the sale (Xavier University now owns that building – I think the old shop is where the rowing team keeps the sculls), but we now have a warehouse in the Fields-Ertel area, and we're delighted to announce that the sale is back and there are more than 60,000 pounds of low-priced books from which to choose (including, of course, a plethora of woodworking titles)!

Located in Governor's Plaza Center, 9131 Fields-Ertel Road (the ZIP code is 45249) the warehouse will be open from 9 a.m.-9 p.m. Monday through Saturday, and 10 a.m.- 7 p.m. Sundays, from Nov. 28 through Jan. 4, 2009. You have more than a month to get great deals ($10 and less!) on books covering the full range of F+W Media subjects including woodworking, antiques, home & garden, quilting, art, firearms, travel, scrapbooking, writing and much more! And if you can’t make it to Cincinnati for the sale? Visit clearancebooks.com, where you’ll find many of the same books, at the same blowout prices.

— Megan Fitzpatrick, managing editor

Above, the Shopbot shed from the Maker Faire in Austin, Texas.

OK, you have a blank sheet of paper and a pencil. Your challenge is to design a house or structure using 4x8 sheets of plywood without driving a nail or screw. Oh, yeah, did I mention no glue either?

A recently closed exhibit at the Museum of Modern Art in New York showed just how to do it, thanks to the efforts of the architecture and engineering colleges at the Massachusetts Institute of Technology (MIT). You can watch a short video of the New Orleans House being assembled (click on the arrow in the lower right corner of the video player to advance to "Housing for New Orleans"). It took three MIT students just a few days to assemble the 20' x 40' one-story house that's part of the Museum's exhibit "Modern Dwellings: 5 Contemporary Pre-Fab Houses."

How does it work? Instead of stud walls, lengths of plywood strips lock together in an "egg crate" fashion. The exterior plywood edges have "tabs" milled into them so exterior sheets of plywood with corresponding "slots" are applied as a "skin" which, in effect, produces a torsion box. Where plywood sheets butted together, a series of joints not unlike an interlocking puzzle pieces were used.

All this precision cutting of a few hundred sheets of plywood was done using a Shopbot Buddy 48 CNC system. All the parts, according to Ted Hall, president of Shopbot, were then tapped together using a rubber mallet. He added that New York officials insisted all the parts be glued, although that wasn’t necessary to create an extremely rigid structure. In fact, he said, after testing MIT engineers and architects concluded the amount of plywood used could have been reduced by half or more and still provide sufficient strength. The New Orleans House was rated to carry a load of up to 250 people and used more than 500 sheets of plywood.

Why so much plywood? Hall said the MIT plan called for parts to be cut and delivered to the MOMA site in the sequential order of assembly. The material was not cut for optimized yield, which led to more waste, Hall explained.

Another example of the construction method was employed in a shed structure Shopbot produced for Austin, Texas "Maker Faire," where the company was awarded two blue ribbons from the editors of Make magazine – one ribbon for the shed and one for Shopbot Buddy 48 CNC machine. This kind of shed is today a more practical application of the building method because local building officials usually don't require permits for smaller structures and getting them to approve a new construction method is often problematic, Hall explained.

For MIT, the objectives of the design were to use locally available materials to produce a structure that could be erected quickly using parts either made on-site or near-by and require a minimum amount of labor and minimal construction skills. Using good design and engineering "digital cutting techniques put the smarts in the parts,” Hall said. Then, just about anyone could knock together a shed using only a rubber mallet.

Will such building methods catch on? Hall said he hopes to introduce the technique to backyards all over the United States with simple shed designs. And farther into the future? Hall said he dreams one day a customer could walk into a "Kinko's" type business, browse some catalogs, choose a design for not only a shed but kitchen cabinets or coffee tables, then have the parts cut out in the back room on a CNC machine for home assembly.