> Exactly what I'm doing. Except no endoder, stepper driven and likely > needs a bigger motor, and more speed reduction to improve the holding > power. Thats a downright puny motor on it now, and I have a 270 oz/in > currently holding down a stepladder step. 8 wire so slower top speed but > easy on the psu. In fact I think I'll check and see if its shaft is > compatible yet today.
Gene, I just tried an experiment with my CNC router which is MACH3 driven. I set up a spare input on parallel port 2 to be the Home switch input for the A axis. The rotary axis is a small 4" rotary indexer driven by a small stepper. With the home set not activated I do a ref all home which sends each axis home in the following order. First the router is moved up to the top limit/home switch. Then the Y axis is moved towards me to the limit/home switch. Then the router carriage is moved to the left until it reaches the limit/home switch. Finally the rotary indexer starts turning and stops when I activate the switch. Then it moves back in the other direction until I deactivate the switch. That's behaviour as expected. Now I move the rotary axis away from my 0 position to 60 degrees. Move all the other axis away from their home. Then do a ref all home again. Like before, Z first, then Y and X, finally it wants to move A but it can't. Instead I get a message that the Home switch is already active and that I should move it off the switch first. That completes the homing cycle. The A axis is still usable. I can manually set A to 0.0000 by clicking a button on the screen. I can enter in a G0 and then an A5 and see the rotary axis move to 5 degrees. So even if I had a switch for an A axis home, all I get is a warning that the switch is activated and fix it. It doesn't seem to cause any other problems. So I can run my CNC router with or without the A axis connected. As long as the switch is open (NC home switch). I would guess there must be a similar operation for LinuxCNC. I can't test that until I put the big system back together and swap the hard drive for the LinuxCNC version. (Should really make this dual boot but that's a different issue). So perhaps play with your switch polarity (NC verses NO for Home Sensing) and see if you can make that work. John _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
