July 8

er, having trouble remembering how many days have passed here.
today we finished the Ti coupler job. Chris welded the couplers in, then i used a lot of 3M Scotchbrite to remove the welding discoloration. i took the lockring off, scrubbed up all the parts, reassembled, and finally polished the frame to blend the finish. Ti is really cool that way...like the right chainstay had a lot of dents from chain slap, so we just buffed them out with some Scotchbrite on a die grinder. same with a chainstay decal the owner wanted removed. then just lots and lots of polishing with red Scotchbrite

then Chris had me cut a couple miters for a 29er for Mountain Goat Cycles. he's got a nice sturdy mill, a Bridgeport clone (i think) called Millport. hard to describe all the steps involved, and i'd guess the procedure is different depending on the machine and the equipment used. Chris uses a stout machinists' vise with 2 pairs of X-shaped-blocks to hold the tube. on softer alloys, we feed at 3 thousandths/minute. on OX Plat and such, it's 1.5 thousandths/minute. the miter angle is set by the mill head, which is probably accurate to half a degree.

No comments: