Quote: From: andy pugh <bodge...@gmail.com> Subject: Re: [Emc-users] G33 spindle synchronized motion - index, rotary axis, multiple axes To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Message-ID: <can1+yzxyt00tex8udzvticqvtb9akmcjq9hxkmkzjamhzhj...@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1
On 20 September 2013 07:46, propcoder <marius.alks...@gmail.com> wrote: > I set up spindle gear sensor on a metal milling machine with steppers. > Will one sensor be enough for G33? It might be. It won't work for G33.1 (rigid tapping) because one sensor can not give direction information, and G33.1 has a reversal in the middle. End Quote: Andy - let me describe how my 80's vintage 8086/8087 powered CNC mill did this. I call it semi-rigid tapping. The machine pauses above the hole long enough to get a good rpm sample then starts the in feed. When Z hits the programed depth the relays switch to reverse ( brute force no speed ramping ) When the contactor switches to reverse the machine tracks the time between tach pulses and as they get longer it ramps the Z axis feed in sync until the pulse is sensed as shorter than the last pulse, this toggles the feed direction reverse and as the spindle speeds up the feed is synced. My machine has a single prox sensor reading off the gear teeth of the back gear. (Bridgeport style var-drive head) The only RPM ramping is the total inertia of the spindle assy and motor. There is just a forward contactor and a reverse contactor that sends full 3ph line voltage directly to the spindle. Now I fully understand that the key to making this type system work is having enough counts per spindle rotation. A single tach pulse per rotation type speed sensor would be useless on its own. It is also not usable for peck tapping or re-entering the same hole. It gets the job done. I think Gene did a hack that allows G33.1 to come to a complete stop with dwell. This dwell could be made a parameter and allow more choices for driving the spindle. ------------------------------------------------------------------------------ LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/22/13. http://pubads.g.doubleclick.net/gampad/clk?id=64545871&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
