how make toolpath follow center of line? mastercam
I'm not familiar with Mastercam, so there is most likely a better way to do this, but can you set an offset equal to the radius of the cutter? Assuming you pick the correct direction (positive or negative), you should end up following the center of the line.
The easiest way to get the tool to move along the center of the line is to set your "Compensation Type" from "Computer" to "Off". You'll find the drop down menu inside the "Cut Parameters" settings.
You can also use "Stock to leave on walls" (which is near the bottom of the same settings tab) to make minor offsets to the toolpath.