Brenda, the large blade size does have something to do with the breakout as does the drill bit. When drilling holes, especially when they are close together, I always use a 1mm bit and make sure it's sharp, light pressure when drilling and that the ply is hard down on a piece of sacrificial piece of wood, also when I cut a single piece of 1/8th BB ply I usually use a 2/0 or a No.1 blade, nothing larger.