Rocker Arm help
The time would be very similar. With a highspeed machining center you can make 20 or more passes with a proper constant chip load that wont wear the tool as quickly, chatter or rub like a large cutter in the same amount of time with more precision and adjustability. In addition to the adjustability the cost of the smaller cutter is much less. Precision carbide cutters aren't cheap, constant chip load is the key to optimum cutter life. With a full size tool using single roughing pass and spring pass process your only option to adjust the size would be a new cutter. Not to mention the high likelihood of deflection on the roughing pass.
The optimum way to finish the saddle may be to develop a process to bore or hone the saddles from a rotating axis through the center of radius being cut. I am just not sure the gain would justify the challenges, cost and risks associated with a process like that.
How are you positioning the head to do that. If the head is mounted longitudinally in the X axis, the how can you interpolate a radius in the Y axis, using a G02 or G03 interpolation in the Z axis, without at least 20 interpolations per stand? That is figuring on a 1 inch wide stand with a .050" stepover per interpolation, which still won't give that great of a finish, imho. And, it's going to take the same amount of time????? Maybe I can learn something new here, and hopefully I can.
Also, if an approximately .150" deep roughing cut, in aluminum, is deflecting a 7/8" ball mill, in a modern CNC, something is wrong. And then there is a .020" spring pass to clean it up. It better not deflect there, even with a dulling cutter, And, you have modern coolants/lubricants to maximize tool wear, and provide a great finish. I find it hard to think an interpolation is the way to go. But, I'm sure I'm missing some considerations, so if I can learn a new, better way, I'm the better for it.
As a side note, I used to machine ball bearing bores in racing manual transmissions and was not allowed to interpolate those bores. If caught doing that, I was assured I would be shown the door. We could only cut them with a boring head. The reason was because interpolation still uses a point-to-point toolpath, and is not a true radius like could be achieved by using a boring head. The trans were built for NASCAR, so it had to be some of the most nit-picky stuff I have ever seen short of the aerospace industry and NASA.
