Hi guys, welcome to another 3D Clinic with Josh “BoneDoc” and my lovely wife, Inn.

In this edition, we’ll be talking about Knife Edge (KE) Spin. IMHO, KE Spin is one of those “high yield” maneuver, meaning that it’s relatively easy to learn, but it has a high wow factor, and is a definite crowd pleaser.

Basic Stick Input
The basic stick input for a KE spin is simply this:

• Full down elevator
• A little left aileron
• Some left rudder

To exit, simply put right aileron, and right rudder to bring the model to an inverted flat spin, then you can either exit inverted there, roll into a rolling harrier, or just roll upright, and fly away.
Each model is a bit different in the amount of left rudder and left aileron you needed, but if you understand the basic principle, you should be able to KE spin any 3D-capable aircraft. Be forewarned though, KE spin puts a lot of stress on your airframe, and some have known to have fallen apart with this maneuver. But rest assured that any properly built (and uncrashed) 3DHS aircraft can easily withstand this, as I have done hundreds of times to mine.

AILERONS, AILERONS, AILERONS
The key to nailing this maneuver EACH AND EVERYTIME is to properly modulate your ailerons. Once you’re locked in, it’s a piece of cake; all you’d have to do then is to just hold it in place until you decide to exit. But …

• Have you ever tried to KE spin, and for the @#$@ the plane just won’t enter that attitude regardless what you did?
• Have you ever asked yourself, why the $@#% is the plane looking like it’s in an upright flat spin even though you’re putting full down elevator?

… I know I have, and the proper aileron input holds the key here.

I’VE GIVEN HER ALL SHE’S GOT CAPTAIN AND I CAN’NA GIVE HER NO MORE


The key to proper aileron input is to see what your wings are doing, and respond appropriately. When your wings are “upright” (meaning that you can see the top of the wing pointing to the sky), that means that you have TOO MUCH LEFT AILERON, and the correct stick input is to ADD RIGHT AILERON. Just a slight “pump” of the stick is all that’s needed to bring the wing back into a more vertical position.







Vice versa, when the wings are “inverted”, that means that you’re putting TOO MUCH RIGHT AILERON (and consequently are in danger of falling out of the KE spin into an inverted flat spin). The proper action at this time is to PUMP some LEFT AILERON.







When the wings are “vertical” then you’re good to go, and in many models, you can just hold the stick and let the plane fall gracefully in the KE spin


ABANDON SHIP
As always, it’s good to know the exit maneuver for any 3D maneuvers you do. Fortunately, for KE spins, it’s redonkulously easy. Just put in RIGHT AILERON, and RIGHT RUDDER, and you’ll automatically exit in an inverted harrier. From there, you can either, exit into inverted flight, roll into a rolling harrier, or just roll upright, and fly away.

SETUP
Since I've gotten PM's on previous clinic on my setup, I'd thought I'd post that preemtively . Here are the following setup on the two aircraft used in this clinic:
3D Hobby Shop 103” Extra 330 SC
DA 85 on Pitts
Xoar 27x8
Optima 7 / Aurora 9 guidance
HS 7950TH on ailerons and rudder
HS7955TG on elevators

3D Hobby Shop 70” Andrew Jesky Slick
Neu 1512 2D: P32 6.7 gearbox
Castle Creations Phoenix 80
UBEC
Optima 7 / Aurora 9 guidance
HS 5985MG on all surfaces
APC 19x9
Rhino 20C 6S 4900


Enjoy, and as always.... FLY LOW

High Def - 3D Clinic #19 - Nailing Your Knife Edge Spin (6 min 39 sec)

Here's the link to the videos if you'd like to download it yourself
http://young99.net/images/Videos/3DCLINIC19-HD.wmv
http://young99.net/images/Videos/3DCLINIC19-SD.wmv

Special Thanks Again to:

• My lovely wife Inn
• 3D Hobby Shop
• Hitec
• Neu Motors
• Castle Creations
• ADC Vinyl (ADChobbystore.com)

I LOVE YOU JOSIE & GRACIE

awesome job as always

wow badass josh. Great Clinic.

Thanks guys .

there should be a section for these, I like that someone is doing detailed videos on 3d,
mike

another awesome vid Doc! thankyou!

Originally Posted by pitviper51

there should be a section for these, I like that someone is doing detailed videos on 3d,
mike

When Josh finishes a few more I'm going to build a new forum for these to live in.

Vary nice Doc......Thank you for all your help !!!

Glad I could help .

Hey Prof,

No mention of the throttle, how crucial is the throttle setting in this manuever? Higher the throttle faster it spins and the lower the throttle the slower it spins? Maybe it isn't a factor at all, just was curious.

Not crucial, usually med throttle (half stick or so) for me. The spin rate is dependent more on how aggressively the model can pitch.

I have been doing this on the sim for a couple of days, I think tomorrow I will giving it a try.

Awesome vids as usual Josh........
(The Tx in the screen is a nice touch!)

I would like to add that generally speaking.. the KE spin is a gyroscopic maneuver... to get the fuse level/wing vertical... lots of power is needed.... the gyro-precession of the motor when pitched causes forces to level the fuse.... (if the motor turned the prop the other direction, we would need to reverse the direction of the KE spin.....)
Play with it... modulate the power and notice the difference in Fuse angle....

Nearly all my 40% planes would KE spin with nearly no aileron.... the trick is to get the wing stalled so it rotates around the spar rather then fly around....

in this vid... you can see the Sx get quite wound up.... (Actually.. the only abrupt maneuver it will do!! lol)

http://www.giantcircus.com/Videos/SX-Cable-2009.wmv

at about 3 minutes.... all down elev and left rudder....

Great help as always....Thanks

Anytime. Glad it helps .