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fizzy.bleach
Dogtemple
Got all the machining done for (this iteration of) my jig, still waiting on some nuts and bolts coming in the mail but the jist of it is there.
750mm section wasn’t long enough for the uprights. Think I’ll get away with it on the headtube as I’m not going to use a top and bottom mount for the headtube, just a lower and I’ve extended the seattube one with the bit of extrusion that was my stem jig.
Wasn’t sure the 1m piece I’ve used as a base was going to cut it either but it just does. Might alter the design to have a piece coming up at 90deg for a while then put the tilt for the headtube angle further up, that’d get me another couple cm of length.
I wanted to turn cones for the head and seattubes but the compound cross-slide on my dad’s lathe is horrible to use so just went with a stepped design. These pucks could be a lot smaller but 100mm is generally the shortest length of round bar you can buy on eBay, I have no powered means of cutting ali bar so it’d be a toil with the hacksaw and I may turn the pieces into cones in the future if I figure out a way of driving the compound with a drill or something.
Going with the stepped design rather than cones means there’s no real need to hold the headtube from above as well as below and forgoing the upper mount means I can mount long bits of headtube in the jig. I like to keep as much length on the headtube for as long in the build as possible as I find the longer tube can be eyeballed against the seattube much easier than a shorter length when I’m checking alignment.
I’ll turn the bit of bar I bought to make the upper cone down to make a puck for a 1” headtube and if I need to make pucks for other headtube sizes it’ll be half the job!
Other than the pucks the only bits I had to machine were the bits of square ali bar that the upright bolt/hinge to.
I bought 100mm of 1 ½” square bar, hacksawed it in half, chucked it up in the 4 jaw and squared the ends. Then I drilled an 8mm hole for the pivot bolt and 4x 5mm holes to mount it to the base extrusion. As much as I’d tried to align these holes correctly for the channels in the extrusion and to keep the edge of the block flush with the edge of the base I got it wrong and had to widen the holes out to 6mm to give myself some room for adjustment. Once they are nipped down they won’t be going anywhere.
Oh and I’d made the axle block a couple weeks ago for the fork jig. Similar to the blocks above, 10mm hole for the axle to go through, axle nuts hold it in place, then a couple 5mm holes to mount it to the extrusion.
All in I reckon I’ve spend around the £100 mark but that includes all the nuts and bolts and it’s only a matter of a undoing a few of those nuts and bolts to go from frame jig to fork jig to stem jig.