SinkStrainer

(Drill & mill sink drain strainer)
(Ed Nisley KE4ZNU -- Digital Machinist 5.1 Spring 2010)
(polycarbonate or acrylic sheet)
(External clamps at -x-y and +x-y corners)
(Origin at center of sheet)
(**** Metric units ****)

#<_PI> = 3.141592659265359		(comes in handy here and there)

(--------------------)
(-- Section Controls)

#<_DoDrilling>	= 1
#<_DoEdge>	= 1
#<_DoTabs>	= 1

(--------------------)
(-- Tool change position for G28 command)
(all tools must be manually aligned to same Z value!)

#<_ToolX> =   0				(X)
#<_ToolY> =   0				(Y)
#<_ToolZ> =   2				(Z  drill touching a 2" block)

#5161 =   [#<_ToolX> / 1]		(X)
#5162 =   [#<_ToolY> / 1]		(Y)
#5163 =   [#<_ToolZ> / 1]		(Z)

#<_TraverseZ>	=  .04			(traverse clearance level)

(-- Piece dimensions and sizes)

#<_PlateSizeZ>	= .189			(Z sheet thickness)

#<_DrillDia>	= .094						(actual drill dia)
#<_DrillRPM>	= 1000						(Must use 3k rpm head)
#<_DrillFeed> 	= [#<_DrillRPM> * #<_DrillDia> / 60]		(was 40 )
#<_DrillDepth>	= [#<_PlateSizeZ> + #<_DrillDia> / 3]		(Z travel including drill tip)
#<_OutsideDia>	= 2.44				(OD of finished strainer)
#<_OutsideRadius> = [#<_OutsideDia> / 2]	(outside radius)

#<_Ring1Radius>	= [#<_OutsideRadius> - 2.46933 * #<_DrillDia>]	(radius of outer ring of holes)
#<_Ring2Radius>	= [#<_Ring1Radius> - 2.46933 * #<_DrillDia>]	(radius of 2nd ring)
#<_Ring3Radius>	= [#<_Ring2Radius> - 2.46933 * #<_DrillDia>]	(radius of 3rd ring)
#<_Ring4Radius>	= [#<_Ring3Radius> - 2.46933 * #<_DrillDia>]	(radius of 4th ring)


#<_FeedTraverse> = 30			(was 500 alignment moves - no material contact!)

(------------------------)
(-- Useful functions)

(----- Drill holes around circle)
(   Parameters: #1=Circle radius, #2=Hole dia, #3=Phase)
(	Phase = 0.0 - hole on +X axis)
(			1.0 - space on +X axis)

O9000 SUB

#<HoleWidthAngle> = [2 * ASIN [#2/[2 * #1]]]		(angle subtended by hole dia)
#<NumHoles>	= FIX[360 / [2 * #<HoleWidthAngle>]]	(integer number of holes + spaces)
#<HoleAngle>	= [360 / #<NumHoles>]			(angle between successive holes)

#<DrillAngle>	= [#3 * #<HoleAngle> / 2]		(starting angle for drilling)

O9010 DO

#<HoleX> 	= [#1 * COS[#<DrillAngle>]]		(find hole coordinates)
#<HoleY>	= [#1 * SIN[#<DrillAngle>]]
G81 X#<HoleX> Y#<HoleY> Z[0 - #<_DrillDepth>] R#<_TraverseZ> F#<_DrillFeed>

#<DrillAngle>	= [#<DrillAngle> + #<HoleAngle>]	(step to next hole)
O9010 WHILE [360 GT #<DrillAngle>]

O9000 ENDSUB


(------------------------)
(----- The Main Event!)

G17 G20 G40 G49 G54 G80 G90 G94		(force everything to start properly...)

M5			(spindle off)

(msg,Verify origin at center-surface, then hit Continue)
M0			(wait for resume)
G0 Z#<_ToolZ>		(to tool change)
G28

(debug,Load #<_DrillDia> drill, set #<_DrillRPM> rpm, then hit Continue)
M0			(wait for resume)
M3			(spindle CW)

G0 X0 Y0		(to safe center point)

(-- Drill hole circles)

O990 IF [#<_DoDrilling>]

O9000 CALL	[#<_Ring1Radius>] [#<_DrillDia>] [0.0]

O9000 CALL	[#<_Ring2Radius>] [#<_DrillDia>] [0.0]

O9000 CALL	[#<_Ring3Radius>] [#<_DrillDia>] [0.0]

O9000 CALL	[#<_Ring4Radius>] [#<_DrillDia>] [0.0]


(G81 X0 Y0 Z[0 - #<_DrillDepth>] R#<_TraverseZ> F#<_DrillFeed>)

O990 ENDIF



G40				(comp off)

G0 Z#<_ToolZ>		(to tool change)
G28

M30		(done!)