Originally Posted by quorneng
I think you will find that my "home made" fan unit is not so far off the thrust to watt ratio of commercial units. It just does it a much lower power.
I think you might find that's not actually the case.. no fault of what you have done in the build, but without stators and suiotable blade design you are always going to be struggling to get any where near a unit thats designed for the job.
If we take a cheap and cheerful GWS 64mm an unit as an example..
GWS EDF-64 fitted with a GWS GWBLM005A brushless motor. This fan draws 10.8A on 3 cells (11.1V), which is 2.2A less than your unit is pulling an a similar battery. The GWS fan gives 301g of thrust
This shouldn't stop it being a interesting and fun project but a modified PC cooling fan isn't ever going to work as well as a specially designed EDF unit.