Desgined it because all other parts I found didn't fit good enough or are too low and crash into the paper clip that holds the print bed.
I had an issue with my printer, caused by the cooling fan which blows the air direct on the temperature sensor of the heater. This results in a way too high temperature for example I set the temperature to 215°C and through the cooling fan the heater thought it is too cold and heats up to 265°C.
Make sure your temperature sensor is protected from the cooling air.
I will design an additional part which covers the heater and the sensor.
Or you use kapton tape to cover the extruder block with the heater and the temperature sensor.
I designed a new fan duct:
This solves my issues and is more compact anyway :)