Rocker Arm help

B3RE said
The saddles seem to be consistent, in a bad way. In a production machining environment, a pass would be made across the saddles from one end of the head to the other, and then a stepover and a return pass back to the starting point. Why they don't use a 7/8" ball mill and make one single pass defies logic.

A radius gauge may fit reasonably well after the heads have been run awhile, because the high spot will have flattened out. But, any light under the gauge means the radius is not true, and the contact area between the shaft and the saddle is reduced.

Coming from a tool and die making environment making plastic injection molds and precision manufacturing fixtures for 25 years, machining an arc like this with a single pass with specific sized tool is not the way to it. A single pass with a large cutter will typically result in a poor finish from chatter, rapid tool wear, and material tearing. You will also likely have issues from tool deflection.

I cant say for sure exactly how Speedmaster is doing this and I am not saying that there isn't issues with them. I am saying in a production and precisions machining environment as well a smaller ball mill with the shape being interpolated (3D cutter path) with a highspeed machine will yield the best results for precision, finish, and manufacturability. This will lead to much better tool life, and better consistency across the board.