mkmk: further improvements and updates

- mkmk: adjust board position
- mkmk: reorder output such that the edge is cut last, reducing board shift
- mkmk: reduce nominal mill diameter for large holes and slots, to increase
  hole/slot size
- mkmk: generate "plot" target in Makefile, to visualize the output
- mkmk: use toolpath file for "cngt" instead of calculating the reference
  point manually

atusb/cam2/mkmk

@@ -8,13 +8,11 @@ mm
 gerber 35mil ../atusb-PCB_Edges.gbr
 align 1 8.1mm 11.2mm	# align relative to board corner
 translate 25mm 2mm	# move to PCB zone assigned to project
-translate 2mm 17mm	# move a bit further
-array 19mm 36mm 1 0	# skip over previous boards
+translate 2mm 21mm	# move a bit further
+array 19mm 36mm 3 0	# skip over previous boards
 z 0 -56.1mm		# board surface
 z -0.8mm		# board thickness
 z -0.5mm		# tool extra depth
-offset
-write mill.gp
 clear
 
 excellon ../atusb.drl
@@ -22,11 +20,15 @@ drill 7mil 15mil	# 12.5-13.5 mil drill
 write drill.gp
 
 remainder
-mill 35mil 0.01mm	# 35 mil endmill
-append mill.gp
+mill 32mil 0.01mm	# 35 mil endmill; pretend it is a little smaller
+write mill.gp
 
 remainder
 empty
+
+gerber 35mil ../atusb-PCB_Edges.gbr
+offset
+append mill.gp
 EOF
 
 
@@ -38,7 +40,7 @@ cat <<EOF >Makefile
 SPOOL=/home/moko/svn.openmoko.org/developers/werner/cncmap/spool/spool
 CNGT=/home/qi/cae-tools/cngt/cngt
 
-.PHONY:		mill drill cng
+.PHONY:		mill drill cng plot
 
 mill:
 		PORT=/dev/ttyUSB0 \$(SPOOL) mill.rml
@@ -47,5 +49,9 @@ drill:
 		PORT=/dev/ttyUSB0 \$(SPOOL) drill.rml
 
 cng:
-		\$(CNGT) -56.1 20 50 39
+		\$(CNGT) -56.1 20 mill.gp
+
+plot:
+		echo 'plot "drill.gp" with points, "mill.gp" with lines' | \
+		  gnuplot -persist
 EOF