a lot has been happening.
i plan to begin construction proper tomorrow afternoon, following my furniture class. the first braze is the steerer-to-crown. i'm planning to do it in brass, because i'm worried about the second braze that area will see, blades/stiffeners to crown.
i filed down the stainless plug-in front drops to fit the fork blades, with some difficulty. good clamping of the drop and a good 2nd cut flat file were the keys. they're considerably oversized, or at least they felt that way after a couple hours' work on them.
i still need to trim the blade tops to length, probably using the abrasive shop saw. then i have to wait for an MSC order to arrive with some wire drill bits to replace the ones i lost out of Freddy Parr's pinning kit. the first drill bit (into the lug pre-fluxing) is a #41 wire gauge, the second bit is a #43. these, of course, don't correspond to any fractional size; i tired that.
i had cut my TT and DT too short for the current design iteration, but i just got around to ordering replacements, as well as a new set of rear drops, all from Kirk at Pacenti Cycle Design. the new drops are socket verticals with one set of eyelets. i hadn't realized before i did research that a rack has to be attached to a cast-in eyelet, not a brazed-on one. next project is a rear triangle jig to get those verticals lined up.
i've been collecting new and used parts for this new frame for a while now. last Friday i took receipt of the last of the wheel parts, which came from AEBike.com, Harris Cyclery in Mass., and various eBay auctions and local Craigslist purchasers. so now i'm also working on a set of wheels, including my first non-singlespeed rear wheel.
hubs: Deore XT 9-spd 36h rear, Deore LX 32h front
rims: Salsa Delgado Cross rear, Sun CR-18 front
spokes: all DT Alpine III, triple butted, 2.34-1.8-2.0 x 292 rear and 300 mm front
the triple-butted spokes fit nicely into the XL holes of Deore hubs (2.6 instead of the usual 2.4 mm).
i'm between college visits for a few days now. RISD in providence and WIT in boston this past weekend, Parsons in NYC next. RISD has several amazing shops, but no CNC in the industrial design shop, and it looked like their machine tools don't get a lot of use (i'd like to be pretty handy with a mill and lathe in 3 years). Parsons, i know from a phone call to them, has CNC machines and a 3D printer in their product design shop, plus an interesting program call "integrated design" that seems to consist of designing/making/studying whatever one wants, plus a few required classes.
i should have an internship for this spring lined up by Christmas, by a wonderfully fortunate series of events. specifically, the fact that i can braze is a big reason i'm being considered. i've been busy working on the application amongst everything else.
the semester is wrapping up, and that means finishing the pieces i've been making for my classes. framebuilding skills have really come in handy in working on the piece for my metal sculpture class, which i'll unveil here after its completion.
i underestimated how nuanced filing is. the proper direction and angle of the stroke in relation to both the vise and the workpiece is something learned by doing a lot of filing. mitering practice was a big help there.
at almost the last minute, i started to experiment with oxy-acetylene welding areas i had previously MIG welded. the plan was to smooth out the contours of the joints, which is impossible with MIG. it's typically done by grinding or filing, but puddling the steel and allowing it to assume a rather natural shape at the joints proved faster and more in line with the aesthetics of the rest of the piece. wow, i seriously go to art school.
i also kinda brass-plated one small area by brazing a thin layer of brass over the bare steel. my sculpture teacher, who had seen me unsuccessfully try to brass braze months ago, watched. afterwards, i was talking to him about learning to braze. the part that took me forever to learn, that i think had been the source of much of my frustration, was adjusting the flame at the torch handle; the key is to get the gases slowly flowing out of the tip, and use a barely carburizing flame. the acetylene has to be at nearly as low pressure as is possible, with just a touch of oxygen mixed in. the gases should be faster/hotter for brass, of course, i'm especially talking about silver brazing here.