To do that you need a pattern maker's bit with the bearing on the shank. Since you are making such a shallow groove you'll want a fairly short one otherwise your pattern will need to be very thick. There are some pattern style bits for mortising door hinges that would be about right for that like this one from Freud: https://www.amazon.ca/Freud-16-560-...=2025&creative=165953&creativeASIN=B000BV7RC2Ill try to explain..Sont have a pic right now ..sorry..
I will cut a shallow groove in the top of these flutes.It will be either 3/8",1/2" or 3/4" wide and approx. 1/16 in in depth..I will take a small piece of wood matching the groove in width. I will just do a radius or curve on one end that matches the what I did with router...It really could be done with a sander but I figured I could do several of them if I had used a patternmakers bit set up.I will take a pattern block that I have made already and it could go on top or bottom of blocks to made or shaped....These "blocks" will be able to slide a little bad and forth in the groove as an adjustment for the flute....If I can do I may carve something and attach it to the top of these blocks but that doesnt really have anything to do with the patternmakers bit.
Also how would you hold the small piece to the pattern piece? Some type of jig or just clamp it some how?
Yes ..just making the end having a radius like a dowel. (like you had split a dowel and glued the half on the end) ..Could do it with the jigsaw and sander...just wanted to duplicate it if I could..Sorry flutemaker but I'm really thick. Do you mean that you want to make the end of a 3/4 piece of wood round like a dowel and leave the rest of the 1 1/2 flat?
Based on your description This solution seems best.......
You can also do that job with a guide bushing and straight bit. You would just need to make a wider slot for the guide bushing to slide around in.