Frankenstein Carriage - Ring Cooling Duct

A ring duct for the Frankenstein E3D carriage. Nothing more to say, really

There are 3 STLs:

1. 9_ring_duct.STL - Low flow through the ring, 1.5mm diameter duct nozzles
2. 9_ring_duct_2mm_holes.STL - Low flow through the ring, 2mm diameter duct nozzles
3. 9_ring_duct_2mm_holes_high_flow.STL - High flow ring, 2mm diameter duct nozzles