Leigh R9 dovetail jig set up and use on router table

[tom coleman]

I will get a Leigh R9 jig next week and want to use it on router table to make dovetail and box joints for joining sides of small boxes and trays using 1/2 inch oak/walnut. I have looked at videos and it looks pretty straight forward and looks like a well made jig. The directions call for fabricating a wood beam and backer board set up to EXACT measurements. Looking for tips from experienced users on fabricating this beam and do's and don'ts to avoid ruining the template by accidentally nipping an aluminum finger against a carbide bit