worktop radius

[snezza]

OK thanks very much for all of this i will give it another go tommorrow one last thing am i right In thinking there will not be any worktop to pivot off at that corner because the worktop isnt wide enough?

You won't need to pivot off the worktop at all.....!!??

It's easier to do a quick rough sketch, hopefully this will show what I mean......

   

Make the jig separately, then place it in position on the corner of the worktop you want to rout.