Hello Nick,
I've refrained from answering your post until now because I have only set the blades once, and so I have virtually no experience to draw upon. But I'll gladly pass on what I was shown.
I understand setting the blades is a matter of adjusting, checking, adjusting again etc., the number of iterations hopefully diminishing as experience is gained.
Ensure the machine is disconnected from the mains.
Two hardwood strips placed on the outfeed table and overhanging the cutter block are used to initially get the blade height reasonably close, whereupon the outer screws are tightened to just nip the blade and hold it in position, rather than to firmly fix it.
A hardwood strip with two inscribed lines 2 to 3mm apart is then used alternately on the left and right hand sides of the outfeed table to determine what adjustment is necessary. The strip is placed so that it overhangs the cutter block. It helps to place a small weight on top of the strip – I use an expired D battery.
The cutter block is rotated by hand so that the blade catches the hardwood strip and carries it forward a few millimeters before disengaging. The objective is to set the blade so that the strip is carried forward 2 to 3mm.
If the blade is too low and the holding screws are not too tight then a small allen key can be used at the end of the cutter block to hook beneath the blade and raise it.
If the blade is too high then firm pressure on the blade will hopefully overcome the friction and lower it. I'm told the tiny adjustments are felt rather than seen.
Of course adjusting one side of the blade tends to affect the other side, but by repeating the process the same 'carried forward' distance (2 to 3mm) can eventually be achieved at both left and right ends of the cutter block, whereupon the blade can be firmly fixed in position.
Jack