first up the fork jig. it's at least within a mm of square, about as best as i could manage with a drill press and miter saw. the axle block is part of a 2x4 that was in the scrap pile. it's just glued to the backboard now, i've drilled pilot holes into it from the back, next is to drive wood screws.
the bit must have walked or something because after measuring the axle's actual height and subtracting half the fork blade's height, it turns out i've only got about 64.5 mm rake, and actually it's maybe a half mm more on the right side. either i'll live with it or i'll try the Paterek fork cold un-twisting method: insert a long screwdriver between the blades and pry them in the necessary direction.
i made the opening for access to the the crown by drilling out the corners with a 1 1/2" spade bit in an electric drill, then connected the holes with a jigsaw. looks like i could have made it even smaller and still left plenty of room for drilling and pinning.
the next addition will likely be a section of angle iron at the left side, to which i'll clamp the steerer for pinning. i'll probably start on that tomorrow. our shop has a horizontal band saw for cutting metal, with a hydraulic mechanism to control how fast it cuts--sounds perfect for 1/8" thick angle iron.
now to the molten metal...wait, make that later...
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2 comments:
Hey there- looks like you're making some progress on getting set up.
Where did you get the idea for a wood fork jig? Is it from that talbot book? Seems like using wood for that would be problematic, esp. in a humid area. I've done A LOT of woodworking and one thing you learn is that wood moves. That plywood might stay flat for awhile, but the 2x4 will change a bunch. OK for framing a house, but it might give you problems when trying to keep things within a millimeter. Maple would make a much more stable block, but it might cost the same as a few pieces of steel. fwiw
-Chauncey
yea, i'm concerned about the 2x4. 'twas a nice piece, totally unwarped as far as i could tell, but yea maple would be way better. i'm keeping my eye on the public scrap pile for a nice little chunk.
the jig design is a blatant Talbot rip-off...search for talbot in the little box at the top there and you can download his drawings. i'm replacing his 2x2 clamping blocks with angle iron, to avoid problems with warped 2x2s. angle iron is pretty cheap too and seems very dimensionally stable. maybe theres some way to replace the 2x4 axle block with an angle iron contraption? i'm working on it while listening to lectures.
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