Fan Backwash eliminator and finger guard for Ormerod hot end

The fan on the Ormerod hot end produces a lot of backwash. This backwash eliminator is based on a design by kwikius (Andy), which I have modified to make it thin enough to allow the hot end to slide behind the Duet enclosure on the Ormerod 1. It is held in place by 50mm countersunk screws instead of the original clips. You can either use just 2 screws (which replace the original 2 screws used to hold the fan, heatsink block, heatsink and plastic parts together), or you can drill 2 more holes in