the jig was dead simple....

16mm lump of chipboard
cut a 60mm wide slot in the middle of it
tap in 1/4 whit threads and screw in 4 small coach bolts
use tie-down straps to hold firmly on the deck
adjust the coach bolts up/down as required and check constantly that the set-point for the router is correct





I must have checked each move a hundred times, I figured it HAD to be right and I would only have ONE shot at this....