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Chapter 2. Active Deskchop: > The Pulley Mounting Bracket - Pg. 49

MAKE: PROJECTS Eccentric Cubicle Lacking a lathe, chuck a 2" hole saw and cut a circle out of 1 / 2 " (or thereabouts) maple. There's the core of your pulley, about 1 15 / 16 " diameter, complete with perfectly centered 1 / 4 " mounting hole. If you want to proceed with an all-wood pulley, at this stage you can secure a 1 / 4 -20 bolt through the mounting hole with two nuts and a lockwasher, chuck it into your drill, and grind a shallow groove into the circumference of the wooden disk with your choice of abrasives. It doesn't need to be excessively deep: 1 / 16 " is enough if it's well defined. Alternately, you can use a 2 1 / 4 " holesaw to cut two larger disks from 3 / 16 " plywood and sandwich all three together to form your pulley. Feel free to improvise. I like brass, so I went with a brass-wood-brass sandwich. I marked the center points of a pair of 2 1 / 4 " circles onto a piece of 18-gauge brass plate, traced the outlines with a compass, and cut them out on the scroll saw. I assembled the sandwich using two-part epoxy glue, and clamped it in my wood vise until it was cured. This design gave me the aesthetic I was after with relative ease, and let me get a tad fancy with the next step of the process. The Pulley Mounting Bracket It's another wood sandwich kinda thing, designed for stability and smooth operation. Quarter-inch ID brass tubing is used as a bushing to minimize friction: Cut it about 1 / 32 " longer than the thickness of the main bracket component and epoxy it into place with the excess protruding towards the pulley side where it can act as a spacer and keep the pulley surface from contacting the bracket. The curved lower portion is cut from the piece of wood you cut the pulley core from, with the thickness reduced a tad with a bit of judicious sanding. I used a section of a fudgsicle stick for the middle spacer, and held the whole thing together with glue and a pair of 3 / 16 " dowels. There's a lot of finicky little detail sanding needed on this assembly, which I advise doing as you shape each component; that way is lots easier than trying to negotiate the nooks and crannies after glue-up. When the assembly is complete, position and glue it in place on the trestle. I set a couple of finishing brads through the spacer section into the trestle crosspiece to really secure the joint, but frankly, it was overkill. Once again, consult the cutting diagram or your workpiece for specifics. [Figure 02.22, Figure 02.23] Figure 02.24: The blade: the crux of the guillotine biscuit, as it were. Your dimensions may vary. The Blade Rough out the blade with a hacksaw or the ubiquitous Dremel. You're cutting exceptionally hard metal, so work slowly, and avoid excessive heat-of-friction accumulation, which could break the temper of the metal and diminish its strength. True up the dimensions and angles of the rough blank with patient, determined filework, and slightly round all edges and corners except for the cutting edge. When the blade drops during use it is essentially in freefall; you can go a long way toward minimizing friction and resistance by simply smoothing out the rough edges. [Figure 02.24] The cutting edge that you'll be forming is similar to a chisel's: one side gets a 70-degree angle. Rough in the bevel with a coarse file, then gradually refine the edge with progressively finer abrasives. The angle isn't critically important, but the closer you get to it, the better for making mit der awezumslicenchoppen. [Figure 02.25] Surface finishing the rest of the blade is optional: I generally 38