Ballista Object, Image 1[i.imgur.com]
Ballista Object, Image 2[i.imgur.com]

Anyone capable of actually modding it for use in-game, add me and we can talk I guess. I still have a bit to do in terms of texturing and optimizing, but it's almost there. There's a lot here so I was thinking the use would be something like;

Upon holding F after it has been fired or is in "idle" (just built) you get the option:
Prepare Device

Prepare Device does the following animation: Rail slides forward, string gets hooked up, and then the wheel can be cranked back (unsure how this should actually unfold.. i.e. should it always fire at full power? if so->) or cranks back automatically. This will cause the string to pull the arms and the arms should rotate back (obviously faked, appearing as though under tension). If it hasn't been used for 5 mins, it should probably return to idle. I was going to mention a system to have the machine take maintainence damage, but I think it's too demanding.

You then have the option to load a bolt or aim:

Aim | Load Bolt

If you don't have a bolt, maybe it comes up with some message telling you to get a bolt.

Then when it's loaded you have the options:
Aim | Fire | Unload Bolt

Aim is still vague, not sure the best way to give someone "aim" capability. There are two pivots, from the stand up the first is part of the stand, and rotates left/right. The second is where the frame connects to the actual ballista and provides the up/down. Also there should be some amount of aim degree lock (especially downward). Unsure on how much exactly. I would say to provide a trajectory but I know a lot of people are against that kind of thing. A crosshair at the very least would be useful.

Fire launches a bolt with a decent amount of speed. I'd use the crossbow as a reference, and it should have a bit more power than that, able to hit things in sieging range.

Unload bolt gives you your bolt back.

Update: Stand texturing complete. Hopefully I can texture the rest fairly quickly.
Stand Texturing Complete[i.imgur.com] - All boards have their own unique texture (shared on only 1 tex map!)
Update 2: Base texturing (mostly) complete. Still have to do the ropes, string, and irons.
Base Texturing Complete[i.imgur.com]