Moving axis on models

Apologies for what is likely a noob question, being completely new to blender and relatively new to JME. I have a model with a few nodes that should be tied together, a tank with a turret and a gun, that I’ve created in blender. When i rotate the tank, everything works fine, but when I rotate the turret, the axis is somewhere near the front of the tank. I need to move the axis back, but haven’t the foggiest how. Is that something in Blender, or in JME? Any ideas?

The pictures in the links highlight the issue better than I can do here. And yes the gun needs to follow the turret, but lets crawl before we walk, eh?

Tank image 1, at neutral position

Tank image 2, after rotating the turret 180 degrees.



I think you could animate that in Blender, but it probably wouldn't make much sense to do so.

With my turrets I like to break them down to keep things simple.

You essentially have three seperate moving parts - the vehicle hull, the turret and the gun barrel.

I make each one a seperate node, and break the model in to three.

When you break it up in Blender, make sure the origin is where you want the center of rotation to be - so it will be at the end for the barrel, in the middle for the turret.

Then just attach them as child nodes one to another, and set the necessary offsets.

This is a shade more work to set up than just loading a model but the rotations work right, and it