What you are asking Atom is not an easy mod as not only mechanically is challenging, electrically also, as the fans are controlled through CAN bus so you have to make sure that what you connect don’t overload the fan electronics but let you control the speed ( unless you want to just connect to the 24V and keep the fan always on ). As part of my hotend improvements, I have already been thinking about how to increase the part cooling capacity as it appealed to me too low and you just confirmed it.
I just have a mockup and design idea, unfortunately, which I still don’t have time neither printer to work on ( for a couple of weeks at least ).
This idea includes two of the fans I’ve already found as Alternative Hotend Cooling 2, which each provides 3.3 CFM and consume only 0.05A each ( the actual fan consumes 0.1A) so fit nicely in parallel and a redesign of the actual fan duct to fit them. The mockup looks like:
The horizontal fan is inside the printhead and is quite a tight fit. It has to be snapped into the duct from the side after removing the left cover and the electronics.
The Vertical fan is outside and also snapped in the duct to be easily removed as it blocks the access to the extruder and is good to keep easy access.
If we make it to work mechanically with a good duct design that fits, we can have a total of 6.6 CFM (vs 3.7CFM) and electrically compatible and firmware controllable fans.
If anybody is able to work in it from the mechanical point of view, I’m glad to help as I can (the good part to have an inactive printer is that is not a big deal to dismantle it to learn).