i have a fan on my extruder
where do you need the fan? printing object or fins?
here is how my fan is set up from the factory, does the job with a jhead
For me i had the fan pointed more on the cooling fins and less for the part and for whatever reason it worked great.
You need a fan for the cooling fins. In addition you may have a layer cooling fan as the one you show in the picture. Without the former it will work for a while until a big plug is formed (so do not get confident because it works initially without a fan; now you guess why I know that).
i also ordered another fan so ill print some mounts, maybe an e3d style one for the fins
I use a 25mm fan for the fins
ok, i ordered a 40mm but i found this
ill rob a 25mm fan off my rc car, i have 2 on the motor and i only need one
You might need to disassemble a J-Head at temperature, especially if melted plastic got into the threads.
I’d be interested to hear how well the alu hot end works. Having such a long zone between the hot end and cooling fins, and not much of a heatbreak, would seem to be a negative.
i have the hotend
it prints amazingly, i found the fins keep cool without a fan directly on them
the nozzle shape is nice, bridges and flat spots print great
i have sped up the print speed form around 30mm/s to around 40mm/s without any ill effects
i couldn’t find any putty to hold the thermistor in place so i wrapped it in aluminium foil, enough to keep it there snugly and tied the wires off