How to change angle of shooter?

[ksafin]

I saw a similar thread but wasn't seeing the kind of discussion I had in mind.

For changing the angle of a launcher, how would you go about doing it?

Assume point blank that it's a 20" shoot with one or two wheels on one side. Now where do we go?

I'm just lost as to what kind of motor to use, reduction to use, gearbox to use, but most importantly how to even mount the launcher to some kind of pivoting mechanism that utilizes that motor. Just lost.