Problems building a springboard

So, I have a basic springboard (similar to Portal 2 for those who know). My script handles the rotation at a high rate of speed when the trigger is hit. All of that works. But when a character steps on it, they don't go flying like they should, the springboard slides out from under them. It's like the magician pulling the tablecloth out from the table, but the dishes stay on. So then I tried to fake it by adding explosive force, but am still not getting them to fly. It's like they're too heavy for it. Any suggestions on how I can get this to work? I just need them to step on the pressure plate and fly across a space of about 50-100 meters.