I'd been asked to turn down a motorbike triple tree (aka triple clamp or yoke), so a supplied bearing would fit on it. After much head-scratching, it was determined that a faceplate would be the most obvious option.
Of course... obvious != easy; it took a good 3 hours of tapping and adjusting to get the tube centered & running true. There must be an easier way...
Here it is mounted on the faceplate:
I used the mill clamping kit to hold it; the shims are necessary to make the tube run true (another
to Bogs, who gave me the brass shim stock that happened to be exactly the right size). I've already taken the first few cuts in the above pic. Because access was such a pain (the steering lock "bumps" on the yoke seriously impeded tool access), I ended up using the very edge of a Mircona parting tool:
Small, slow cuts were the order of the day. I gradually whittled down the main diameter until the bearing was an easy slide fit down the majority of the tube; the goal was to make the last 20mm (the width of the bearing) a reasonably tight push-fit. In the event, I got it down to that level, but the final cut just ended up a touch over; so whilst the bearing sat nicely, it didn't grip properly. A smear of Loctite was therefore employed to keep the bearing in place. Normally, of course, it'll be squashed up against the cup with a hefty bolt, so in theory the loctite is unnecessary.
The finished article:
I did get a little chattering on the final cuts, hence the slightly sub-standard surface finish; but this'll all be hidden away in a tube anyway, so it's no big deal.
