A tumble is not exactly a manuever, just what a lot of people call things like Snap rolls and maybe even Waterfalls. Basically, it's when the airplane is tumbling!

A snap roll is basically a horizontal spin. Throw the sticks in the corners (there are 8 different cominations excluding the throttle position) and see what happens. With the throws turned up that Cap will do some of the best snap rolls of any airplane! An example is full up elevator, full right rudder, full right aileron, and full throttle. You can start them at any attitude, but to start, just try them from straight and level or maybe a little nose up.

For a Knife Edge, just roll the airplane 90 degrees (wingtips perpendicular to the ground) and hold in enough rudder to maintain altitude. Do this at full throttle. Use whatever elevator and aileron inputs you need to hold the wings 90 degrees to the ground and keep the airplane headed straight. Some airplanes need a lot of corrections and others need very little.

If I remember correctly, my Kyosho Cap liked to pitch towards it's belly in KE (knife edge). There was pretty much no roll coupling...It was easy to KE.