Pimping the mini-lathe

;Weird thread
;Why? Because a CNC lathe can!

;Tapered 3 start RH thread 23/57"OD  x Pi TPcm, 11/7 Chi long, with a 23/19e taper angle.
;Z0 is end of stock.

#<_pi> = 3.14159
#<_e>  = 2.71828
#<_chi>= 30.3

#<_starts>           = 3
#<_OD>               = [23/57*25.4]
#<_Z_LeadIn>         = [#<_pi>*4]
#<_Pitch>            = [#<_pi>]
#<_ThreadDepth>      = [#<_pi> /3 ]
#<_ThreadLength>     =-[#<_chi>*11/7]
#<_TaperAngle>       = [23/19*#<_e>] 
#<_NumThreadPasses>  = ROUND[#<_ThreadDepth>/0.1]

#<_SmallDia>         = [#<_OD> - [SIN[#<_TaperAngle>*2]] *[#<_Z_LeadIn> + ABS[ #<_ThreadLength>]]]
#<_DiaChange>        = [#<_OD> - #<_SmallDia>]
#<_NumCuttingPasses> = ROUND[#<_DiaChange>]
#<_stockDia> = 20
#<_stockOff> = [#<_stockDia>  - #<_OD>    ]
#<_NumsizePasses> = ROUND[#<_stockOff>]

#<_feedrate>         = 150
#<_Speed>            = 1000
#1                   = 1 ; Index start passes
#2                   = 1 ; Index threading passes
#3                   = 1 ; Index cutting passes
#4                  = 1 ;Index resize

O110 sub ;Cut taper
	O110 while [#3 LE #<_NumCuttingPasses>]
		G0 Z[#<_Z_LeadIn>]
	   	   X[#<_SmallDia> + [[#<_NumCuttingPasses> - #3] * [#<_DiaChange> / #<_NumCuttingPasses> ]]]
		G01 Z[#<_ThreadLength>] X[#<_OD> + [[#<_NumCuttingPasses> - #3] * [#<_DiaChange> / #<_NumCuttingPasses> ]]] F#<_Feedrate>
		G0 X[#<_OD> + #<_DiaChange>]
		#3 = [#3 +1]
	O110 Endwhile
O110 endsub

O111 sub ; Cut Thread

	O100 while [#1 LE #<_starts>]
		O101 while [#2 LE#<_NumThreadPasses>]
			G0 Z[#<_Z_LeadIn> + [[#1 - 1] * [#<_Pitch>/#<_starts>]]]
	   	   	   X[#<_SmallDia> - [[#2]*[#<_ThreadDepth> / #<_NumThreadPasses> ]]]
			G33 Z[#<_ThreadLength>]  X[#<_OD> - [[#2 - 1] * [#<_ThreadDepth>/ #<_NumThreadPasses> ]]] K#<_Pitch> 
			G0 X[#<_OD> + #<_DiaChange>]
        		#2 = [#2 + 1]
			
		O101 endwhile
		M5
		G4 P2
		M3 
		G4 P2
		#2 =1
		#1 = [#1 +1]
                #<_SmallDia> = [#<_SmallDia> - [SIN[#<_TaperAngle>]*[#1 -1] * [#<_Pitch>/#<_starts>]]]
	O100 EndWhile	
O111 endsub

O120 Sub ; resize stock 
      O121 while [ #4 LE #<_NumsizePasses>]
               M3 
               G0 X [#<_stockDia> +1]
               G0 Z1
               G01 X [#<_stockDia> - [#<_stockOff> / #<_NumsizePasses> * #4] ]   F #<_feedrate>
               g01 Z [#<_ThreadLength>]
               #4 = [#4+1]
         O121 endwhile
O120 endsub


;Main
G18 G21 G40 G49 G54 G80 G94 G90 G7
F#<_Feedrate> S#<_Speed>
M3
G4 P2
O120 call
O110 call
M5
G4 P2
M3
O111 call
M9 M5 
M2