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John John is offline
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Default Tapered pin or split collar

Buerste wrote:
We have to replace a 6" diameter x 1.5" wide cast iron gear that has two
broken teeth. It's in the middle of a 4' long 1.25" dia. shaft. The
original gear was pinned to the shaft with a .5" taper pin through a boss on
the gear, but the pin bore was drilled and reamed by hand at the factory and
it's not centered. A mechanic wants to try to hit the tapered hole in the
shaft and I don't think that will ever work. If anything, the new pin
should go 90 degrees from the original.

My idea is to turn down the boss from 2.75" to 2.25" and saw-cut across the
boss in two places (+) and clamp the gear on the shaft with a split collar
on the bisected boss. I think it'll hold almost as good as the pin.





put the shaft in a Bridgeport or other vertical and hold the thing with
a steady rest on each end. Line up the hole with the drill and then
slide the shaft to where you want to drill the hole... then drill it and
then ream it for the pin... Make sure you index mark the gear to the
shaft because it will only go on one way, Also make sure you ream the
hole the same way the old taper goes in the shaft

John