So I almost destroyed my hand trying to thickness plane a 1/2” piece I had already box jointed. So I thought, hey, this Rockler router box joint jig comes with a 1/4” guide... so I planed down some boards. But when I router, no bueno, ref. picture. Is it because; I’m loading both at the same time, or because all I had at the time was harbor fright 1/4” striaght bit. Walnut and maple, not a hard enough wood? I feelnlike a spiral wouldn’t help much, but maybe it has to do with sharpness? Would love pointers, first time ever joining a forum.