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Chapter 2. Active Deskchop: > Assembly - Pg. 53

MAKE: PROJECTS Eccentric Cubicle steel wool. With repurposed brass, there's a good chance that it's been heavily laquered to preserve that blindingly bright gloss. It's gotta come off. Reach for the thinner. If you can fully immerse the brass, more the better; otherwise make do with medium steel wool soaked in thinner. It'll take several cycles of "soak steelwool, rub like crazy, soak steelwool" to lay bare the alloy, but perseverance and a light touch will be rewarded. Once the bare metal is exposed, clean up any surface imperfections (and there are bound to be a few . . . besides resisting corrosion, lacquering is used to effectively conceal any number of manufacturing sins) with the finest-grade emery paper possible, and give the metal light but thorough rubdowns with fine and extra-fine steel wool. You should now be able to use a rag and small amounts of buffing compound (okay, toothpaste) to bring a near mirror finish to the metal. Work small areas at a time, and be patient; the results are very satisfying. Of course, a cloth wheel on a bench grinder with commercial rubbing compound will get the job done in a flash with admirable results as well. There's a really gloopy Turtle Wax rubbing compound I highly recommend, if you're of a commercial bent. Once the surfaces are as shiny as you want them to be, you can apply a protective coating to ward off the evil forces of corrosion. You may want to try a few coats of clear lacquer. Personally, I've never been fond of the look. I'll use a quick hit of an acrylic floor polish if I want that "Brite `N Shinee" thing. I prefer a quick wipedown with WD-40 for inhibiting corrosion, which leaves the metal surface looking more like metal and less like some space-age plastic. Figure 02.32: The hidden mysteries of the lunette revealed!! Assembly Putting this thing together is a piece of cake if you paid attention during fabrication and made all the bits the right shape and size. If not, you're hooped. [Figure 02.32] Cut two pieces of brass rod 2 1 / 8 " long. These are your lunette guides. Use a small hammer to peen a dome onto one end of each; your aim is to widen and round out the top slightly. The brass is soft and will cooperate with you. Why are you doing this? To capture the upper section of the lunette. Use two-part epoxy adhesive sparingly to lock the guide pins in place on the lower lunette section, and cap the upper section with a strip of belt leather attached with double-faced tape. This cushions the impact of the blade and weightbox during use. The blade must be positioned in the guide slots before mounting the trestle assembly into the pocket on the base. Use countersunk 1 1 / 4 " #6 brass screws through the bottom of the base to secure the trestle. [Figure 02.33] In a burst of artsy-fartsy nonsense, I used 8-24 threaded rod and acorn nuts to attach the weightbox to the blade. Notice the orientation of the blade: the bevel of the cutting edge is on the outside, the flat side flush to the lunette. [Figure 02.34] Cut a piece of 1 / 4 " ID brass tubing to length. What length? You want it about 1 / 32 " longer than the piece of tube you've already set into the pulley mountng bracket. Brass on brass bushings are a surprisingly effective substitute for a traditional ballbearing assembly (called a "race" by those who oughta know). You'll be amazed at how smooth and solid the action is when you get it set up right. [Figure 02.35 , Figure 02.36] Stringing the hoist cord is next. I use a length of the 70/30 cotton-polyester handyman's chalkline that I normally use to string the torsion skeins of ballistae and mangonels. In keeping with the minimalist aesthetic of this enterprise, there's no trigger mechanism involved: just a cord attached to the blade with a knob on the other end to hold onto. Get artistic with your choice of knob. I'm using a knurled brass thumbnut that originated on a thrift-shop pepper mill. Here's a neat trick for doing a blind attachment of a cord or cable. You can use it on both ends of the hoist cord. Drill through the end of an acorn nut with a hole slightly larger than the diameter of the cord you're using. Run the cord through the hole, and tie a large retention knot to prevent the 42