The long road of experimenting is over for the most part. We turn a full ball with the boring head approach, making odd changes as we go - finally ending up with a fairly satisfactory tool grind, which now is in a newly made tool holder. Chip formation looks good and pretty much what was sought after. There may be small tweaks to follow but essentially only to grind new tooling, possibly including a small left side relief on the tool so as to give better clearance on the left side of the ball -- and also have the 'arc sweep' position set up a bit better on a future ball turn. Thanks to all who have followed this long saga!
11 сен 2024