I kind of know how to do it in 2D - I wrote a few lines of code that translate carthesian 2D (x,y - where the mouse is pointing) to numer of steps for the motors. So pretty much something like a typical drawbot.
Sure it isn't 100% accurate as I have to convert from float (returned by dist) to integers (number of steps) I would have to do it anyway
So, you're trying to do this by pulling on your barrel with wires, at some distance away from the pivots? Oooph
Yeah that's pretty much the idea - say what you want but since it would require only TWO motors and very limited hardware to cover 360 deg arc and wide range of elevations - so I guess it's kind of cool idea. If this approach prove to be inaccurate then I might as well switch to theaded rods
the angles you're giving as input are themselves only approximate solutions to the real problem of hitting a specified landing spot
external ballistics IS very complex - I can assure you I am aware of it and I know there are lots of variables that have effect on it. Whether or not the projectile is stabilised (and how well it's stabilised), its BC value, muzzle velocity etc.
Mind you this post is pretty much about building a platform that can point the launcher in the right direction. It's in no way a complete system.
anyway have a look at this -> not mine but pretty cool >> http://www.spudfiles.com/forums/viewtopic,p,185036.html#185036