"I haven't really thought about the recharge times, but I think the ballista should have a recharge time of 55, since that's what the vanilla catapult has, and the scorpio should have a time less then that, perhaps 45. I guess the battering ram would have the smallest recharge time, but I'm not sure what would be a good value. 35 maybe?"
Ballista = 55
Scorpio = 45
Aries = 35
"The ideal firing animation would be the one used in Rome 2 Total War, but I can't find any videos that clearly show it. Basically, the projectile should be winched back, but it should be staggered rather than smooth, so it'll be winched back, stop, then be winched back again and so on. The wooden arms need to move closer together during this animation, perhaps you could get that to work by putting a rotating node in the large cylinders that have the rope wrapped around them. The winch levers should also rotate in a staggered way. Once the projectile has been drawn back, there should a short delay before firing. With the Rome 2 animations, there are two men controlling the winch levers, and one man who then releases a rope to make the weapon fire, hence the short delay (we shouldn't bother about the rope though). I guess this would end up taking up longer than the current 55 recharge time, so rather than making the animations fit a set time, perhaps you could just focus on making the animation look right and then we get the recharge time from that."