Solved Nodes won't collide with triangles

My node section starts like this:

Code:

        "nodes": [
        ["id", "posX", "posY", "posZ"],
        {"selfcollision":true}, 
        {"collision":true},
        {"frictionCoef":0.7}, 
        {"nodeMaterial":"|NM_METAL"}, 
        {"nodeWeight":10},

Then the collision triangles are defined in a "triangles" section.

Everything looks fine in game with the collision triangles visible however the nodes glide straight through. (It's for the buffers of my train)

Happy to send all the relevant files to someone who actually know's what they're doing...

Cheers!