; === HELICAL MILLING ===

; Helix-mill a hole with pecking.
; Assumes metric, XY plane, feedrate, and tool compensation are set.
O<helix_mill> sub
  #<xcenter> = #1 ; [mm] X center
  #<ycenter> = #2 ; [mm] Y center
  #<radius>  = #3 ; [mm] Hole radius
  #<zstart>  = #4 ; [mm] Z start position
  #<zend>    = #5 ; [mm] Z end position

  G0 X[ #<xcenter> - #<radius> ] Y#<ycenter>

  G0 Z#<zstart>
  #<znow> = #<zstart>

  ; Mill out body with several full helical turns
  O100 while [ #<znow> GT [ #<zend> + #<_zstep> ] ]

    #<znow> = [ #<znow> - #<_zstep> ]
    G2 I#<radius> J0 Z#<znow>

    ; Peck
    G0 Z#<zstart>
    G0 Z#<znow>

  O100 endwhile

  G2 I#<radius> J0 Z#<zend>

  ; Peck
  G0 Z#<zstart>
  G0 Z#<zend>

  ; Flat out the bottom
  G2 I#<radius> J0

O<helix_mill> endsub

; Make one polygonal milling turn.
; Assumes metric, XY plane, feedrate, and tool compensation are set.
O<polygon_turn> sub
  #<xcenter> = #1 ; [mm] X center
  #<ycenter> = #2 ; [mm] Y center
  #<radius>  = #3 ; [mm] Hole radius
  #<zstart>  = #4 ; [mm] Z start position
  #<zend>    = #5 ; [mm] Z end position
  #<edges>   = #6 ;      Edge count

  #<zedgestep> = [ [ #<zend> - #<zstart> ] / #<edges> ]
  #<anglestep> = [ 360.0 / #<edges> ]

  #<znow>      = #<zstart>
  #<angle>     = 120.

  O100 repeat [ #<edges> ]

    #<znow>  = [ #<znow>  + #<zedgestep> ]
    G1 X[ #<xcenter> + cos[#<angle>] * #<radius> ] Y[ #<ycenter> + sin[#<angle>] * #<radius> ] Z#<znow>
    #<angle> = [ #<angle> - #<anglestep> ]

  O100 endrepeat

O<polygon_turn> endsub

; Helix-mill a polygonal hole.
; Assumes metric, XY plane, feedrate, and tool compensation are set.
O<polygon_mill> sub
  #<xcenter> = #1 ; [mm] X center
  #<ycenter> = #2 ; [mm] Y center
  #<radius>  = #3 ; [mm] Hole radius
  #<zstart>  = #4 ; [mm] Z start position
  #<zend>    = #5 ; [mm] Z end position
  #<edges>   = #6 ;      Edge count

  G0 X[ #<xcenter> - #<radius> ] Y#<ycenter>

  G0 Z#<zstart>
  #<znow>  = #<zstart>
  #<zprev> = #<zstart>

  ; Mill out body with several full helical turns
  O100 while [ #<znow> GT [ #<zend> + #<_zstep> ] ]

    #<znow>  = [ #<znow> - #<_zstep> ]
    O<polygon_turn> call [#<xcenter>] [#<ycenter>] [#<radius>] [#<zprev>] [#<znow>] [#<edges>]
    #<zprev> = #<znow>

  O100 endwhile

  O<polygon_turn> call [#<xcenter>] [#<ycenter>] [#<radius>] [#<zprev>] [#<zend>] [#<edges>]

  ; Flat out the bottom
  O<polygon_turn> call [#<xcenter>] [#<ycenter>] [#<radius>] [#<zend>] [#<zend>] [#<edges>]

O<polygon_mill> endsub

; === SCREW/NUT POCKETING ===

; Mill a pocket for a nut, part #1 (nut pocket).
; Assumes metric, XY plane, feedrate, and tool diameter are set.
O<nut_pocket_1> sub
  #<xcenter>      = #1 ; [mm] X center
  #<ycenter>      = #2 ; [mm] Y center
  #<nut_depth>    = #3 ; [mm] Nut depth
  #<nut_radius>   = #4 ; [mm] Nut radius
  #<screw_radius> = #5 ; [mm] Screw radius

  ; Initial positioning
  G0 X#<xcenter> Y#<ycenter>

  ; Cutter compensation to the right.
  G42

  ; Make a pocket for nut.
  #<rnow> = #<nut_radius>
  O100 while [ #<rnow> GT #<screw_radius> ]

    O<polygon_mill> call [#<xcenter>] [#<ycenter>] [#<rnow>] [0.] [-#<nut_depth>] [6]

    #<rnow> = [ #<rnow> - #5410 * 0.9 ] ; Subtract 90% tool diameter

    G0 Z0.0 ; Get tool up for another plunge

  O100 endwhile

  ; Cleanup.
  G40
  G0 Z#<_zsafe>

O<nut_pocket_1> endsub

; Mill a nut pocket, part #2 (screw body pocket).
; Assumes metric, XY plane, feedrate, and tool diameter are set.
O<nut_pocket_2> sub
  #<xcenter>      = #1 ; [mm] X center
  #<ycenter>      = #2 ; [mm] Y center
  #<screw_radius> = #3 ; [mm] Screw radius
  #<thickness>    = #4 ; [mm] Sheet thickness

  #<hole_radius> = [ #<screw_radius> - #5410 / 2 ]
  O<helix_mill> call [#<xcenter>] [#<ycenter>] [#<hole_radius>] [0] [-#<thickness>]

  ; Cleanup.
  G0 Z#<_zsafe>

O<nut_pocket_2> endsub

; --- BEGIN CONFIGURATION ---

; Don't forget to set up tool table.

S2000 F250

#<_zsafe>        = 30.  ; [mm] Safe Z
#<_zstep>        = 3.5  ; [mm] Z step

#<_thickness>    = 13.5 ; [mm] Sheet thickness
#<_nut_radius>   = 3.95 ; [mm] Nut radius
#<_nut_depth>    = 7.5  ; [mm] Nut depth
#<_screw_radius> = 2.   ; [mm] Screw radius

#<_grid_step>    = 30.  ; [mm] Nut grid step
#<_grid_width>   = 180. ; [mm] Grid width
#<_grid_length>  = 210. ; [mm] Grid length

; --- END CONFIGURATION ---

G21 G90 G17 ; Metric, Absolute, XY plane

O<grid> sub
  #<gridx> = 0.
  O100 while [ #<gridx> LE #<_grid_width> ]
    #<gridy> = 0.
    O110 while [ #<gridy> LE #<_grid_length> ]
      O120 if [ #1 EQ 1 ]
        O<nut_pocket_1> call [#<gridx>] [#<gridy>] [#<_nut_depth>] [#<_nut_radius>] [#<_screw_radius>]
      O120 elseif [ #1 EQ 2 ]
        O<nut_pocket_2> call [#<gridx>] [#<gridy>] [#<_screw_radius>] [#<_thickness>]
      O120 endif
      #<gridy> = [ #<gridy> + #<_grid_step> ]
    O110 endwhile
    #<gridx> = [ #<gridx> + #<_grid_step> ]
  O100 endwhile
O<grid> endsub

G0 Z#<_zsafe>
T4 M6 G43 ; 1.5mm cylindrical
M3
O<grid> call [1]

G0 Z#<_zsafe>
T2 M6 G43 ; 3.175mm cylindrical
M3
O<grid> call [2]

G0 Z#<_zsafe>
M2