%
( *************************************************************************** )
( * Biquad tool                                                             * )
( * Metrical RS274/NGC program                                              * )
( * Copyright 2008 Michael Buesch <mb@bu3sch.de>                            * )
( * Licensed under the GNU/GPL version 3                                    * )
( *                                                                         * )
( * Origin is in the center of the leftmost quad [X-]. Z0 = surface.        * )
( *************************************************************************** )

#<_cutter_dia> = 6		( Cutter diameter )
#<_speed> = 1500		( min^-1 )
#<_feed> = 1000			( mm/min )

( Workpiece origin coordinates [in absolute machine coordinates] )
#<origin_x> = -30
#<origin_y> = 0
#<origin_z> = -10

( Quad dimensions )
#<_nr> = 4				( Number of quads. [For one biquad say 2] )
#<_depth> = 5			( Cutting depth )
#<_depth_step> = 2.5	( Step for cutting in depth)
#<wire_dia> = 1			( Diameter of the wire used )
#<width> = 30.5			( Square width [wire center] )

( Internal parameters )
#<width> = [#<width> - #<wire_dia>] ( Adjust to used wire )
#<_c> = [SIN[45] * #<width>] ( Cathetus )
#<_current_cutter_dia> = #<_cutter_dia>

G17 G21 G40 G49 G80 G90 G94 ( Initial modes )
G10 L2 P1 X#<origin_x> Y#<origin_y> Z#<origin_z>

G53 G0 X0 Y0 Z0
G54 S#<_speed> F#<_feed> M3


( Subroutine for the outlines of one quad )
O1 sub
	#<z> = 0
	G0 X-10 Y[#<_c> + 10]
	G0 Z0.5
	G1 Z0
	O911 while [#<z> lt #<_depth>]

		G1 X-10 Y[#<_c> + 10]
		G91 G1 Z[-1 * #<_depth_step>]
		G90
		G41.1 D#<_current_cutter_dia>
		G1 X0 Y#<_c> (Entry move)

		G1 X#<_c> Y0
		G1 X0 Y[-1 * #<_c>]
		G1 X[-1 * #<_c>] Y0
		G1 X0 Y#<_c>

		G40 X10 Y[#<_c> + 10]

		#<z> = [#<z> + #<_depth_step>]
	O911 endwhile
	G0 Z1
O1 endsub


( Sub-subroutine for the rest )
( #1 is the X factor, #2 is the Y factor. )
O3 sub
	#<z> = 0
	G0 X[[#<_c> + #<_cutter_dia>/2] * #1] Y[[#<_c> + #<_cutter_dia>/2 + 2] * #2]
	G0 Z0.5
	G1 Z0
	O921 while [#<z> lt #<_depth>]
		G0 X[[#<_c> + #<_cutter_dia>/2] * #1] Y[[#<_c> + #<_cutter_dia>/2 + 2] * #2]
		G91 G1 Z[-1 * #<_depth_step>]
		G90
		G1 Y[[1 + 6] * #2]
		G1 Y[[#<_c> + #<_cutter_dia>/2 + 2] * #2]
		G0 X[[#<_c> + #<_cutter_dia>/2 - 5] * #1]
		G1 Y[[1 + 5] * #2]
		G1 Y[[#<_c> + #<_cutter_dia>/2 + 2] * #2]
		G0 X[[#<_c> + #<_cutter_dia>/2 - 10] * #1]
		G1 Y[[1 + 10] * #2]
		G1 Y[[#<_c> + #<_cutter_dia>/2 + 2] * #2]
		G0 X[[#<_c> + #<_cutter_dia>/2 - 15] * #1]
		G1 Y[[1 + 15] * #2]
		G1 Y[[#<_c> + #<_cutter_dia>/2 + 2] * #2]
		G0 X[[#<_c> + #<_cutter_dia>/2 - 20] * #1]
		G1 Y[[1 + 20] * #2]
		G1 Y[[#<_c> + #<_cutter_dia>/2 + 2] * #2]
		G0 X[[#<_c> + #<_cutter_dia>/2 - 25] * #1]
		G1 Y[[1 + 23] * #2]
		G1 Y[[#<_c> + #<_cutter_dia>/2 + 2] * #2]
		#<z> = [#<z> + #<_depth_step>]
	O921 endwhile
	G0 Z1


O3 endsub

( Subroutine for the rest )
O2 sub
	O3 call [1] [1]		( X+, Y+ )
	O3 call [-1] [1]	( X-, Y+ )
	O3 call [-1] [-1]	( X-, Y- )
	O3 call [1] [-1]	( X+, Y- )
O2 endsub


#<z> = 0
G0 X[[#<_c> + #<_cutter_dia>/2 + 1] * -1 - 10] Y[#<_c> + #<_cutter_dia>/2 + 1]
G0 Z0.5
G1 Z0
O901 while [#<z> lt #<_depth>]
	G0 X[[#<_c> + #<_cutter_dia>/2 + 1] * -1 - 10] Y[#<_c> + #<_cutter_dia>/2 + 1]
	G91 G1 Z[-1 * #<_depth_step>]
	G90
	G1 X[[#<_c>*2 + #<_cutter_dia> + 1] * #<_nr>]
	G1 Y[[#<_c> + #<_cutter_dia>/2 + 1] * -1]
	G1 X[[#<_c> + #<_cutter_dia>/2 + 1] * -1]
	G1 Y[#<_c> + #<_cutter_dia>/2 + 1]
	#<z> = [#<z> + #<_depth_step>]
O901 endwhile
G0 Z1

O902 while [1 eq 1]
	( Remove parts that don't belong to the quads )
	O2 call

	( Mill quad outlines. First with a small diameter offset. )
	#<_current_cutter_dia> = [#<_cutter_dia> + 0.05]
	O1 call
	( And without offset and depth stepping )
	#<old_step> = #<_depth_step>
	#<_depth_step> = #<_depth>
	#<_current_cutter_dia> = #<_cutter_dia>
	O1 call
	#<_depth_step> = #<old_step>

	#<_nr> = [#<_nr> - 1]
	O903 if [ #<_nr> le 0 ]
		O902 break ( No more quad to go )
	O903 endif
	( Move origin to next quad )
	G0 X0
	G92 X[#<_c> * -2] ( Move origin FIXME! wire diameter!)
O902 endwhile

G53 G0 X0 Y0 Z0
M30

%
vim: syntax=rs274ngc ts=4