emc-users-requ...@lists.sourceforge.net wrote: > On 25 July 2010 14:53, Schooner <schoone...@tiscali.co.uk> wrote: >> > The ATC is currently assigned to axis A, so I could just write GCode to >> > achieve the same result, but would rather it responded properly to M6. >> > >> > Can anyone point me to some info or tell me the secret?! >> ArcEye -
I have a 12-station turret running on my Tsugami Lathe as a pseudo-servo controlled joint - some ClassicLadder grabs the tool change request (Tx M6), runs the hydraulic locks, ensures the rest of the machine is in feed-hold, controls a PID component that is driving a small VFD that drives the AC induction motor that spins the turret. The VFD has a very quick accel/decel curve in it. I have an incremental encoder on the output of the gearbox (there is a high- and low- speed clutch as well as a brake on the turret gearbox) that reads about 180,000 pulses per full turret rotation. The index pulse on the encoder is ignored and generated by a separate inductive sensor on the turret itself, once per true revolution. The ladder is written to go directly to the tool number (hand-coded encoder position) as opposed to the "shortest distance"; thus if I'm at tool 12, and call tool 1 (which is right next to it physically), the turret will "unwind" all the way from 12 to 1 - which is not the fastest, but since it runs the change in high-speed for the majority of the time, I get a maximum tool change speed of about 3 to 4 seconds; and for that I'm not going to complain about. The ladder shifts the gearbox into high for most of the transit, and downshifts for about one tool position; it reduces the "hunting" (since the VFD really isn't designed for that) to a minimum. The "joint" doesn't exist as an actual axis; so it isn't subject to modes or feed hold status of EMC. Homing is accomplished by button on startup (or any convenient time afterwards); it winds and unwinds the turret searching for the index pulse, then sets tool 1 ready for the first cutting operation. The index is ignored after that. You can check out the entire process here at: http://www.casafrog.com/cfblog/ or the turret-specific pages starting around: http://www.casafrog.com/cfblog/?p=1214 Cheers, Ted. ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://ad.doubleclick.net/clk;226879339;13503038;l? http://clk.atdmt.com/CRS/go/247765532/direct/01/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
