Lathe profiling cutter comp problems

[steveHDPJT]

For whatever reason Fusion is generating these fairly silly tool paths when I select cutter comp to be "in control". For example, using Turning Profile to turn down a diameter to 31.8mm with cutter comp set to "in control" comes up with this:

Part OD is 31.80mm. Inner radius in the profiling op is set to 15.90mm (exactly half). Yet it comes up with these weird divots and redundant loops in the toolpath, and then spits out code at 30.2mm - it shouldn't be doing this, the whole purpose of using G41/42 is that you use the exact part geometry for imaginary tool point and correct the toolpath using tool radius compensation, right? The tool radius in Fusion is set to 0.80mm... but since I'm not asking it to compensate within Fusion that should be irrelevant, and the code should spit out at 31.8 regardless? Am I missing something or is this actually a fundamental flaw?

[HughesTooling]

It looks like you need to set the tool up to use tip centre in the tool library if you want to use In Control compensation. 

Mark

[steveHDPJT]

Thanks, that seems to have done the trick. I don't understand why that is though - if compensation is set to "in control" then irrespective of all else, the toolpath's generated X/Y/Z values should follow the actual part geometry exactly (plus any stock to leave that may be specified), no?