MAKE: PROJECTS Eccentric Cubicle Figure 04.01: The almost sling-like nature of a golf swing. It's a pendulum wif a bit extra, innit? What I'm sayin' is: no marbles, no cheese, no nuts, and no berries. Other than that, knock yourself (and quite likely your co-workers) out. Think of a golf swing as a fancy way of getting a really long hammer to whack the hell out of a little ball. That said, to golfers, the geometry of the motion is critical. The backslope angle of this particular swing plane (ooh! ooh! I used an offi- cial golf term!) is 30 degrees, which is spec'd more for ease of fabrication than for any resemblance to actual golf swing geometry. I did however, set the club shaft to radius ratio within reality-based measurements. No shit: golfers take their kit damned seriously. Research- ing this build had me elbow-deep in golf club technical minutiae for about 10 days. Some of the propaganda being thrown around had obviously sound physics behind it, other bits of it was such blatant balloon juice as to make high-end audiophile gear appear scientifically realistic ("These \$300 petrified oak volume knobs will maximize your overall sound field imaging clarity and impart a subtle implication of amber to bass clarinet passages"). Anyway, between referencing innumerable pages of learned discourse, marketing poopsheets, and whiny blog entries, and two days spent measuring swap meet golf clubs, I arrived at 43" as being "yer average shaft length." Oddly, golfers don't seem to consider girth to be an issue. Further research into human anatomy (me, a tape measure, and every poor sap who walked through my door for a week) arrived at 34" as "yer average reach," from the center of the shoulders to the knuckles of clasped hands extended for- wards, for an average arm-to-shaft ratio of +/­ 1:1.25. The pitch of the clubface (the amount of backslope on the bit that actually hits the ball) is a club-specific variable related to the amount of loft provided. (Loft as in "angle of ascent," not as in "overpriced attic in Manhattan.") I saw numbers ranging from 7.5 degrees for a right proper "manly" wood ("ladies" can apparently enjoy as much as 31 degrees of ascent-producing goodness) to more than 60 degrees for specialty wedges. The ambitious among you may want to consider fabricating a vari- able-geometry clubface to address the entire range of options. Because Maple Mike is nothing if not manly, I picked a value of 7.5 degrees, on the assumption that altering the tee height and point of contact in the overall arc of the swing can geometri- cally provide real-time variation during usage. Yeah, you'll need to do some math, but it'll be good prac- tice for playing Brain Age. From a design perspective, the mechanism is based around a wooden chassis onto which are bodged the club 104