Slotted both necks for the carbon rods and the truss rods. I used a couple of equal sized spacers on the router guide to give me the three different distanced from the neck edge - just adding or taking out spacers makes it easy and repeatable to cut the slots. The spacers are just two equal thickness pieces of ply.    Quite pleased how these have gone so far. I've not got any basses with carbon neck rods and I've never built one with them so I'll be interested to see if I n