provides extra air circulation flowing in higher speed, and easily takes away more hot air.
Same as previous version yet better.
Fan Duct Switch
Purpose: Control the air flow. Open the switch: allow the air blow straight to the model, and let it cool down fast which could prevent dripping and model’s tip from burned. Close the switch: block the air blowing to the model to cause the warping.
No, it does not have a switch.
PTFE Tube inside the Heating Block
Purpose: To help the filament fed into the nozzle properly, and avoid it being heated too much and cause blockage.
Yes, it has a PTFE tube inserted in the extruder throat.
PLA filament has high tendency of heat deformation.
The inside wall of the PTFE tube is slippery with less friction. It prevents the filament deformation under high temperature.