Part cooling fan blows on the hot block, causes clogging

[garethky]

The part cooling fan, currently in mainline, blows onto the hot block of the mosquito an causes a large temperature differential in the block. A heater tune in RRF with the part cooling fan at 100% will fail as the heater cannot keep the block hot. Its also possible to get filament clogging if the part cooling fan is used at too high of a setting.

A temporary part cooling fan is currently checked into the dev branch to alleviate this issue but its part cooling performance is far from optimized.

Some problems with the design:

• The selected height for the floor of the nozzle is too high
• The openings in the nozzle are too tall, allowing air to flow directly into the hot block.
• There is unequal air distribution between the center vent and the side vents, the center vent passes the majority of the air.

[garethky]

The latest nozzle design has been performing well, printing nice test parts in PETG and PLA. I also don't have any issues tuning the heater with the fan running at 100%.