Big		SLOT D0.85x4.5		Measured approx 0.4mm tip and 20deg
Med		JLU 1.0x5			Approx 0.3mm tip and 15deg
Sml		SD 0.65x7.0			Approx 0.15mm tip and 7deg

Feed: cutting at 0.6 mm/sec = 36 mm/min at 0.1 mm depth
	Using 0.3mm/15deg cutter
	Note that the online calculator expected 0.2mm depth (I adjusted z offset to lighten cutting load) so there were bits of copper left between some traces, annoying
	
Drill: plunge at 0.4 mm/sec = 24 mm/min at 2.2 mm depth, which cuts all the way through and into next board

Need to reverse x or y axis as right now image is mirrored

For round 2 I use 0.3mm/15deg cutter at 0.05mm depth x2 passes and 120 mm/min
	And for board cutout, the 0.4mm/20deg cutter at 0.1mm depth xN passes to reach 2.2mm depth at 120 mm/min; board cutout complete around 17.0mm depth good quality edge
	The board cutout works well, only need to cut down to 1.7mm depth
	However the contour cutout has many rough edges, so this setting is not recommended - either too fast or too shallow or too deep?
	

Some data from https://adapting-camera.blogspot.com/2016/12/making-pcb-with-my-upgraded-diy-cnc.html
Using 22000 RPM, 0.04mm depth, and 450 mm/min
For 7000 RPM, scale down feed to 143 mm/min
And for 0.05mm depth, further reduce to 120 mm/min

New cutters are 20deg, 0.2mm
Width formula = 0.2+0.342*depth
At 0.04mm depth,	0.214mm width
At 0.05mm depth,	0.217mm width

From trial run:
1. Pre-bend the board prior to cutting to ensure that in the middle it is pressing down
2. Align the top horizontal line to the machine axis for a nice aligned shape
3. Depth of cut 0.04mm got most of the board (except edges were too low so not all the way through, and middle was too high so deep and narrow trace left)

Around step 6000~6400 re-start the cut

Plunge rate of 17.5 mm/min with 0.8mm milling bit for drilling through holes seems to be working ok
But depth of -1.7mm does not cut clean all the way through (actually it does, just leaves a bit of material at end to push out)
However with 1.0mm drill bit, also 17.5 mm/min, to -1.8mm leaves a lot of material behind due to the drill bit taper - need deeper hole in this case