EDF inline ?
 

Has anyone ever tryed to put 2 EDF motors in line, I was needing to know if the first motor would cause wash to cavitate the second motor. I want to try something involving 2 motors but if it's been tried and won't work I'd rather know up front. I want to use 2 300 motors and 55 fans, same as on the A-10 Any thoughts on this would be appriciated

RE: EDF inline ?
 

To gain any effective benefit the second fan would have to be pitched as to provide more thrust based on the incoming airspeed. Off the shelf you run the possibility that the exhaust from the first fan might be too fast for the second fan to handle.

RE: EDF inline ?
 

That's what I had originaly figured, also considered using 300 for first motor and 400 for second, not sure about need to reverse direction of second fan to counter thrust, or if that can be done. might just scratch idea and move on :D
Thanks

RE: EDF inline ?
 

On pg 16 of "Mike's Jet Book" by Mike Cherry is a pic of Ralf Dvorak and Heino Dittmar with their P-80's, 110 mm span, 1.15 kgwith retracts. They used two 65 mm impellers facing each other and rotating in opposite directions. It said with properly matched motors there is no need for stators. Claimed "sparkling performance from a small inlet area". The models in the pic appeared to have pretty scale inlets. It said "...using Speed 400 6v/480 race motors and 10 Sanyo 1700 cells thrust is 700 grams with 52 m/sec exhaust velocity."

The captions said a fully molded kit was "soon to be available from Fiber Classics" and that the fans were expected to "soon be available commercially". If they were, I never heard of it.

The book has a 1997 copyright and I have never heard anything more about this tantalizing idea since. Was it just another seemingly good idea that did not pan out or was it a really good idea that got lost in the shuffle and ignored? I've often wondered. Maybe it would be improved with brushless/Lipo technology that was not available back then.

Anybody have any more info about this?