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Chapter 4. Maple Mike: > The Club: Not That Thing You Clamp Onto Your Steering ... - Pg. 135

MAKE: PROJECTS Eccentric Cubicle fitting and pressfitted a length of 1 / 8 " brass rod through the bungee elastic as a locking pin. A few drops of cya- noacrylate on the bungee fabric sheath prevents it from unraveling under stress, and the ends of the locking pin were filed and emeried flush with the curve of the fitting. This component can be filed under "Over-attention to Detail." It's not really needed, but makes a nice touch. The fitting was selected primarily because the ID matched the OD of the bungee I happened to use. Use whatever strikes your fancy. [Figure 04.32] 2. The tension lock itself, which doesn't need to be any- where near as complicated as the one I ended up with: Depending on the diameter of bungee elastic you end up installing, your diameter requirements may vary, but it's in the best interests of tweezability, gusto, and really whacking the shit out of the ball that you at least give your- self the option of harnessing as much wellie as possible. [Figure 04.33, Figure 04.34, Figure 04.35] To accommodate the widest diameter range of bungee elastic, you need a large-scale hole (obviously) with a large- scale spindle screwing into it. Through some bizarre compo- nent accretion process, I ended up with about 2 / 3 of the 7 / 16 -18 threaded cartridge of a gas barbeque valve screwed into a hole I'd drilled and tapped into the compression nut from a 1 2 " brass pipe fitting. Into this compression nut was pressure- / fitted a piece of 1 / 2 " OD brass piping, and the valve cartridge was topped off with a thumbwheel from an antique welding torch held in place by a copper rivet that took me two days to peen properly. Make no mistake, campers: I can complicate anything. In your case, all you really need is something to keep the (taut) bungee elastic from being pulled back through the hole in the chassis. Simple methods? Tie a damned knot. Poke a pointy stick through it. Complicated methods? Well, you just learned how to make cams do stuff. That's one starting point to consider. And lastly . . . 3. The front-side bungee guide: This is another "use what you want, but use something" situation: the component is present to ensure that the exit point of the elastic is exactly parallel to the pulley groove; the main axle of the mechanism takes enough abuse as it is without subjecting it to off-axis strain under load. I fabricated the component pictured from a ¾" piece of the same kind of PEX fitting I used on the bungee pull grip: The inner and outer diameters were just about per- fect, and the ridges provided some textural detail to the part that made it not just another piece of brass tubing. I cut the Figure 04.31: Hoot, mon, it's a bonny wee Brassy Cleek, Seamus. Can ye lend us a fiver 'til the end o' the week? Figure 04.32: Bungee, guide and locking mechanism: Why did the bungee have to be pink? piece to fit, then filed a nice smooth notch sized to accommo- date the elastic into the rim. The component pressfits snugly into chassis, reinforced with my favorite ghastly-smelling-2- part-sets-in-about-90-seconds-startlingly-strong-dollar-store epoxy. [Figure 04.36, Figure 04.37] Hey! You've made most of the pieces. Time to put it together. Glue the chassis to the base. Once it's cured, use the pre- drilled dowel holes in the base as guides to drill 1 / 2 " into the chassis. Set the dowels, let 'em cure, then cut 'em flush. See how easy it is to do with a Kugihiki? [Figure 04.38] 124