If your blades slip in the blade clamp when under tension, Clean the ends of the blades with 150 grit sand paper. The blades have a small amount of oil on them from the manufacturing process. Also periodically.clean the blade clamps by folding a piece of sandpaper in half and insert into the blade clamp and sand the inside of the blade clamp.
Instead of sanding the end of the blades, some people clean off the oil with mineral spirits or lacquer thinner.
