Cutting a curved shape from a block of aluminum

[Jonathan]

Think it does Jon because he's got tool dia in one of the params and does some maths with it but I haven't checked it so could be wrong.!! . . . Terry isn't a muppet so would have took the easy route I'm sure if not.?

To cut the correct concave profile, you need to cut along a diameter which is the tool diameter subtracted from the diameter of the surface you wish to cut. Having looked more carefully, I can confirm that Terry has done this (the line #1000=[#1040-#1030]), so barring other errors, he is not a muppet, at least in this case.

I plotted a graph to demonstrate. The blue line represents the desired surface, red line is the toolpath (so an arc of radius [r_surface-r_tool]), and the red circles represent the tool. You can see it touches nicely at a tangent.



So, sorry Rufe0, but in Jazz's words, you apparently are a muppet!