Cooling duct for Vector 3 Printer

This is a new design for a cooking duct for the Vector 3 Printer replacing that provided in the Magazine Create and print part 91. The duct should be printed with thre duct pointing upwards. No support is needed
Two people have reported that the plastic duct is fouling the hothead This can happen if the heating block is lower due to build tolerances This edition adds two spacers one mm and two mm thick to enable the duct to be lowered