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Grunder Industries ADF-01 Falken build log

#81
I finally got a nice day to try and fly the falken, I didn't build a new plane and I'm glad I didn't because after a few nosedives the cockpit was totally destroyed. I took the advise of @Namactual and didn't sweat the nose damage, and the funny thing is, is that it glides just fine without it!o_O
Anyway I still need to adjust the thrust angle, I tested it by giving it a good toss and then applying throttle and it dives harder when it is given more throttle.
 

L Edge

Active member
#82
I finally got a nice day to try and fly the falken, I didn't build a new plane and I'm glad I didn't because after a few nosedives the cockpit was totally destroyed. I took the advise of @Namactual and didn't sweat the nose damage, and the funny thing is, is that it glides just fine without it!o_O
Anyway I still need to adjust the thrust angle, I tested it by giving it a good toss and then applying throttle and it dives harder when it is given more throttle.
Try about 5 degrees and see what happens.
 
#85
Sorry it has taken me so long to reply, but I wanted to have more to show than just the damage, but here are some pictures of it anyway.

1558659783407.png 1558659864656.png 1558659979991.png

As you can see from the first two pictures the cockpit was completely kiboshed, but worse was the wing bending as can be seen in the last picture. I am pretty sure that this was partly to blame for the violent down pitching that this plane suffered from. However, I think that the main cause was that the motor was directly above the center of gravity, so I decided to make some modifications and build a whole new airframe.
 
#86
Here is my progress on the new build.

1558660738816.png

This picture is just a mock up so I still need to mount the cockpit to the wing. I moved the power pod down so that the motor's thrust line would be in the center of the wing which should take care of the downward pitching moment, but that threw off the geometry of the old cockpit mount, so that will have to be redesigned. I reinforced the leading edge of the center wing panel with some bamboo skewers so that it won't sag like the last one, and I put the servo wires inside the wing so it looks a lot cleaner. I am vey happy with the way this plane looks, and if it flies well then I will start working on making PDF plans.

Also @L Edge I will definitely have video of the maiden flight!
 

L Edge

Active member
#88
If it doesn't fly, I have 2 suggestions for you.

1) When I built mine, I ended up with small elevrons and it's deflections. Try less deflection and have a high expo rate.
2) You have a small area of wing. Can you extend the leading edge by about 1 1/2 to 2" to increase the total wing area and that changes your CG.. Might help you.

This is based on 3 FSW planes I built. Here is one of them.
https://forum.flitetest.com/index.php?threads/forward-swept-wing-using-64mm-edf.57659/
 

L Edge

Active member
#90
Thanks guys!

@ L Edge what were your rates and expo for that X-29? Right now I have 12 degrees and 30 percent expo on both channels.
Finally, got back to internet. My elevon is only 1 1/2" wide and I have only 3/8" max (25 degrees) deflection and my expo is 35 percent for elevator and 30 for aileron. What my concern was your control surface takes up quite a bit of wing surface and with a large deflection of your wing makes it like a 3D airplane, very twitchy. I use very little deflection to make it go.