stupid thing again… leason learned 
changed:
GraphicsDevice.SetVertexBuffers(new VertexBufferBinding(meshPart.VertexBuffer, meshPart.VertexOffset, 0),
new VertexBufferBinding(actor.InstanceBuffer, 0, actor.Count));
to:
GraphicsDevice.SetVertexBuffers(new VertexBufferBinding(meshPart.VertexBuffer, meshPart.VertexOffset, 0),
new VertexBufferBinding(actor.InstanceBuffer, 0, 1));