I have a 22", 8 H, HD loom that is new to me. When I step on a treadle the shed opens but the bottom threads rise up about an inch above the race. This is causing the shuttle to get stuck in the bottom threads or go under the treads it should be traveling over. Can anyone give me some guidance as to the height of the shafts, and should the warp threads be sitting in the middle of the heddle eye or lower?