GRAFCET — CNC Automatic Tool Change
The changeover every SMED study starts with, drawn honestly: a simultaneous divergence runs the swing arm and the magazine index at the same time and a convergence of the same width holds the drawbar until both prove, which is exactly the internal time a single-threaded chart hides.
Make it your own.
title "Machining centre — automatic tool change (M06)"
step 1 "Cutting, spindle running" initial
N "Spindle at speed"
step 2 "Orient spindle, retract Z"
N "Spindle orient"
N "Z to tool-change height"
step 3 "Swing arm to spindle"
N "Arm motor to spindle pocket"
step 4 "Index magazine to pocket"
N "Magazine index motor"
step 5 "Grip spindle tool"
S "Arm gripper close"
step 6 "Present next tool"
N "Pocket to transfer position"
step 7 "Unclamp, swap, clamp"
P "Drawbar unclamp"
D 0.5s "Arm 180 degree rotate"
S "Drawbar clamp"
step 8 "Return arm, restart spindle"
R "Arm gripper close"
N "Spindle start"
transition t1 : "M06 . cycle_stop"
transition t2 : "spindle_oriented . z_at_change"
transition t3 : "arm_at_spindle"
transition t4 : "pocket_in_position"
transition t5 : "gripper_closed . pocket_ready"
transition t6 : "drawbar_clamped . tool_present"
transition t7 : "arm_home . spindle_at_speed"
1 -> t1 -> 2 -> t2
# One transition, two steps: a SIMULTANEOUS divergence, double bar.
simultaneous t2 -> 3, 4
3 -> t3 -> 5
4 -> t4 -> 6
# Two steps, one transition: the convergence that closes it, same width.
simultaneous 5, 6 -> t5
t5 -> 7 -> t6 -> 8 -> t7 -> 1