- Posts
- 16,238
- Location
- Benfleet, Essex
...That today (at last) my order of nuts & bolts arrived and so I began the task of drilling out the holes for the bolt cage on the two freewheel sprockets. I would warn anyone trying to follow this construction method that the sprockets are "Cold Forged" and extremely hard and before I was done I had destroyed 1 Tungsten-Carbide tipped 5mm drill bit and a 6mm 4-flute end mill.
The last hole managed to get out of position as a result of the blunting of the drill-bit/end mill.
However, the unit is assembled and bolted up and everything is aligned and a test-fit of a chain around the drive sprocket shows that there in so interference with the chain from the bolt-heads.
End-on view:
Learnings from today:
The BCD of the bolt cage could have been 4mm or more smaller (schoolboy error, the 4mm of the inside 2mm walled tube was added to the calculations when in fact the edges of hte cap-heads and locknuts could have rested much closer to the main casing of the freewheels).
The last hole managed to get out of position as a result of the blunting of the drill-bit/end mill.
However, the unit is assembled and bolted up and everything is aligned and a test-fit of a chain around the drive sprocket shows that there in so interference with the chain from the bolt-heads.
End-on view:
Learnings from today:
The BCD of the bolt cage could have been 4mm or more smaller (schoolboy error, the 4mm of the inside 2mm walled tube was added to the calculations when in fact the edges of hte cap-heads and locknuts could have rested much closer to the main casing of the freewheels).