in following the venerable tradition "if everything else fails, look how Fanuc does it":
here's what I found on valid operations during feedhold on some Fanuc controls, I wasnt aware of those features, and I summarize them to encourage thought about this sore spot in linuxcnc. during a feed hold you can execute: 1. a 'General Purpose Retract' activated by a button: The tool is retracted along a predefined vector and feed (probably relative to current position) The program is aborted. 2. 'Tool retract and recover': remove tool and return to machining The tool is retracted along a predefined vector and feed (probably relative to current position) on 'retract' button Manual or jogging can be enabled, the control will record this "withdrawal" up to 10 jogs moves returning to auto mode and hitting the 'recovery' button: follow the withdrawal moves in reverse; 'cycle start' will now move the tool to the point where the 'retract button was pressed' There are provisions for 2) during rigid tapping as well. 3. 'Manual intervention and return' after switch to manual mode, tool can be jogged away after return to auto, and pressing 'cycle start', the tool will return to the point where it left off. see p574 of b) for the reentry move ('Non linear interpolation type positioning') 4. 'Threading retract': Feedhold would normally kick in after finishing the current thread and returning to the start point. With this option, the tool immediately retracts with the same chamfer angle as programmed, and returns to the start point. 5. 'Retrace': while 'retrace switch' active: finish current block, then run in reverse (up to ca 100 blocks back) feedhold stops retrace, cycle start continues retrace turning off the retrace switch switches to forward execution again sources: a) http://www.cnc1.com/News/customer-files/CNC_eNewsletter_Mar_2011.pdf b) http://www.cnc1.com/images/customer-files/Fanuc_Manual_Handle_Retrace.pdf c) http://www.cnc1.com/images/customer-files/Fanuc_Retrace.pdf - Michael ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers