Router guide assembly for cutting return bends in radiant flooring underlayment panels

A router guide system for cutting an underlayment panel for a radiant heating system, the underlayment panel including at least two parallel grooves therein said router guide system comprising:

• a guide panel having a top surface, a bottom surface, a longitudinal guide rail on said bottom surface and an arcuate groove extending through said guide panel;
• a pivoting guide pivotally affixed to said top surface of said guide panel;
• and
• a router affixed to said pivoting guide, said router including a cutting bit installed therein, said cutting bit extending through said arcuate groove in said guide panel,
• wherein said router guide is placed over said underlayment panel, said guide rail being received into a first of said grooves said pivoting guide supporting and guiding said rotary cutting device through a 180-degree arc wherein said rotary cutting device cuts a return loop between said first and second grooves.