; Universal helical programme
;
; %x1 = Circle centre X
; %y1 = Circle centre Y
; %z = depth  moved in Z
; %h = diameter of move CUTTER centre!!!!!!!!! allow for radius
; %cut step down in Z each circular path 
%x1 = 275.10
%y1 = -114.60
%z = -7.0
%h = 50.
%cut = 0.5    
F1000.
S600.
T10

%hr = %h/2
%depth = (0 - %z)
%turns = (%depth / %cut)
G61                           ; switch to non CC mode
G40 G80                       ; sets no circular offsets no cycles active
G90                           ; sets in absolute mode
G49                           ; clears any length offsets
G21                           ; declares metric programme
G0 Z0.0 M5                    ; safety line should not move if machine set up properly
G0 X+0.0 Y-0.0                ; safety line should not move if machine set up properly
G43 H10 M6                    ; use tool length offset & prompt for tool change
M07                           ; coolant on
M3                            ; spindle on                      
G00 X%x1 Y%y1                 ; move to centre
G00 Z20.0                     ; rapid to 20mm above surface
G00 Z2.0                      ; rapid to 2mm above surface
G01 Z0.0                      ; feed to surface
N14 G15 I%hr K%cut L%turns    ; make helical moves
Z20.0                         ; rapid to 20mm above surface
M09                           ; coolant off
M05                           ; spindle off
G49                           ; length offsets cleared
G00 Z0.0                      ; rapid to Z zero
G00 X0.0 Y0.0                 ; rapid to X Y zero
M30                           ; end of programme