On 16 August 2010 05:24, Steve Blackmore <[email protected]> wrote: > A "drive line" , as it seems to be called in past posts, should be able > to have any value you want. It's a valid engineering technique to cut > with a zero increment.
I believe it is to define a safe return path for the cutter (and also to let the interpreter know whether to cut an internal or external thread). Returning the tool along a line that skims the thread peaks does not seem that valid to me. "I" defines the distance from the current tool position to the peak of the threads, if you have just completed a turning sequence to finished diameter then that doesn't mean that "I" is zero, it means that it needs to take the value of the X backout you used for the return rapid. > To put that in context, neither does G33, properly! I turn hundreds of > parts per week. 30% have taper threads, they need to be in > specification, to achieve that I need to fudge the pitch with EMC. You have complained of this before, but I have concluded that it is a feature. It is almost no trouble at all to fudge the pitch to be correct, but if you wanted to cut a spiral with only an X pitch (the scroll for a three-jaw chuck, a face-cam, a camera iris control ring) then if G33 always used the Z axis to define a pitch, you would have no way to make it happen. -- atp ------------------------------------------------------------------------------ This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
