Help Needed - Cannon Rotation

Hey guys, I spent the last couple days on and off trying to figure this out for myself but can't seem to. This is the first app I've worked on so I'm still learning the ropes.

I have a cannon in the centre of one of my scenes which is constantly rotating. Every 5 seconds it fires a cannonball and I need the cannonball to come from the end of the cannon. At the moment I have a timer for every 5 seconds to spawn in the cannonball actor and the cannonball actor has a Change Velocity attribute with direction 0. I'm assuming this is the part that needs changing but as I said, I can't figure it out. Basically need it to look like the cannonball actually came out of the cannon, not just fires off in random position. I feel I should also note that the cannonballs currently do fire off in different directions, just not from where I need them to.

Any help would be great! Cheers.