When I was big into 3 D'3 I would put on a 2 inch vane about 9/16 of a inch from the nock and bring the second one up the shaft a 1/2 inch from the first vane and then the third vane a 1/2 up from the second vane. This works like a paddle wheel and the arrow will spine quicker and faster with less vane. I was shooting ACC hyper speeds in the 280's and was working really good for me and made them a good 12 ring getter very accurate. A lot of good 3 D shooter were doing this at one time. Your arrow will stabilize better the farther they are back on the shaft. One reason vanes are feathers were move up the shaft to 3/4 to a inch was for finger shooter for finger clearance on release. Release shooter don't need as much. 9/16 is a good distance for a loop are caliber release.