I want to build a flexy rack. I've never done one before, and I want to make SURE it doesn't weeble, wobble or fall down. I'm going straight for 3/4" rod. *grunt noises* It's going to be a five or six-shelf unit...four-five feet high. What size holes do I drill in the shelves? One-inch? 3/4" would be too tight a fit, no? Thanks.