EDFlerken! aka "Bad Kitty"

Jade_Monkey07

Well-known member
So I was thinking about your plane nose diving problem and in aero design rear swept wings act like they have dyhedral, so inversely forward swept wings will act like they have anhedral(this could be wrong, cant find my source on this so ignore this part of my comment), so you adding in anhedral is effectively doubling the anhedral.
To get it to be more stable you would need to lower the cg to below the roll wing plane. Like hanging a pendulum below the aircraft
As for the nose diving issue. Vectoring the thrust up(pushing the nose up) would help.

I'm going to find a video and link it here in a minute of a star wars plane with anhedral wings, pay attention to how low he had to mount the battery to get it to be stable. And how far back its tilted in normal flight. Almost like a nutball. he explains at 3:30 how low the battery needed to be and that he needed extra ballast on the low wing tips
Hope this can help you iron out some of the flight characteristics you're seeing.
 
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Paracodespoder

Elite member
From all I have read and seen, forward swept wings act the same as back swept wings, being that they do the same as dihedral.
Might be wrong, dunno, I’m not a rocket scientist 😉.
 

Jade_Monkey07

Well-known member
From all I have read and seen, forward swept wings act the same as back swept wings, being that they do the same as dihedral.
Might be wrong, dunno, I’m not a rocket scientist 😉.
I read that somewhere when researching the x29, but I could also be wrong. The one principle that will help him out of all of that will be the pendulum effect. Looking at the harrier and the other high wing anhedral planes is that their cg is below the wing plane.
I was incorrect in my previous statement that forward sweep will cause a pitch down, it will in fact stall at the root and cause a pitch up.
So maybe just get the cg as low as you can and make sure the thrust angle isnt pushing the nose down.
I'll leave my above comment but put a note.
 
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L Edge

Master member
Naw I’m skeerd I’ll lose sight or orientation of it in flight!

Mid7:

Biggest problem you will have is with working with pitch. With a FSW, once you get it tuned, it flies fast as well as being nice and slow.
My first problem was this:


To solve the problem, I extended the fuse(up front) a couple of inches and added a fixed canard (stop at 2:53) to get it to fly nicely.

I have some other concerns that could be causing the nose situation.
Hold plane vertical, find how much throttle it takes to keep it hovering.
let's say 1/2.
now chuck at 2/3 throttle to see what happens,
then try 3/4 and see what happens, might be thrust line.

Got more suggestions with FSW. Best I did is design a rectangular, aft ,forward swept wing that lets it fly morphing from one to another in flight.
 

DronePilot260

New member
Hey guys! Yeah the 70mm definitely works well in this but having the EDF on the bottom proved to be a flaw. I landed too hard and broke all of the blades 😎😁
 

CappyAmeric

Elite member
I am indeed the guy 😎 . This design is super tail heavy and it didn't help that I laminated the whole thing
It is quite tail heavy but balancing it out with weight up front helps somewhat. With a prop, the thrust angle is to nose high unless you have FPV equipment in the nose. Like the FT Versa, the nose needs to be about six inches longer, with zero thrust angle.

EDF is a great idea for a pitch sensitive design like the Flerken - however, EDF underslung or overslung tend to cause huge pitch moments unless the thrust is correctly ducted with the longitudinal axis. I suspect that both your mod and @Mid7night ’s mod suffered from similar issues with directed EDF thrust. In your case, perhaps the unducted EDF robbed too much potential thrust, IMHO.

Congrats on the persistence and a successful maiden.
 

DronePilot260

New member
Just did some more test flights today
 

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