Probably going to have to take some of the offset or helical out of the clamp adjustment because of the narrower diameter shaft. Put an arrow in the jig, loosen the adjustment screws and put the clamp on the jig. Move it around so it rides on the arrow nicely, i.e., flush its entire length. Then just tighten the adjustment screws. May want to move it around a little before you tighten the adjustment screws to get as much helical in it as you can and still make good contact with the shaft the entire length of the clamp, or at least the length of the feather you will put in the clamp. Good luck.