Airfoil aviation E- Conversion

Airfoil Aviation's Power Parafoils

Developing story.... Check back regularly for updates..

Specifications:

Wingspan: 88 In
HEIGHT: 24" (62cm)
MATERIAL: Ripstop Sailcloth
Cells Air INLET and NO outlet
Has cross vented cells to handle gusty winds
FRAME: RAM Air
Total Flying Weight: XXXX.
Motor: Kontronik KBM 42-30 w 3.7:1 GB,
Prop: Master Airscrew Electric 12x8
Cells: 10x2400mah
ESC: Kontronik 45Amp Brushless w BEC
Radio: JR X3810, 2 Standard servos.
Price: $219.00
complete GLOW Powered Kit by http://www.airfoilaviation.com

For those very interested in converting the Airfoil Aviation's GAS powered parafoils
to electric... here is one success story.

This article is about direct modification to the model as it is built for GAS.
Suggestions to alter the model before it is built is listed in the conclusion.
this has been determined by flight testing and validation with other 'similar'
models on the market from Graupner and Hirobo, since these were designed
to be electric from the ground up.

Major Modifications needed

Prop Shroud must be widened to allow a 13 " prop clearence.
This is done by buying a larger than 1/4 inch diameter K & S tube and
extending the 1/4 diameter shroud..

Bend the tubing by inserting the wider K&S tubing and bending it over
a inverted garbage can slowly... The Garbage can acts as a round jig.. to
provide support as you expand the ring.

Extension tube is Super Glued in place after it is inserted into the original 1/4 inch tubing.

Hot glue is required to plug up all the holes so that dirt does not go in. Hot glue is required to SMOOTH the joints of the shroud so that the steering lines does not get in the way.

Wire ties left over are used to smooth the transition to high and low points around the shroud so that the foil cables do not snag.. Believe me they WILL SNAG regardless of height of the protrusion. Make sure the hot glue is smooth and nice by using a HEAT GUN to RE-MELT the glue to a nice consistent flow. Make sure the transition from metal to hot glue is smooth too (Gradual thin to thick layer) If not trim with wire cutter and Re-Apply heat.

The steering servos at NEUTRAL (neutral elevator) should pull down both
sides of the back of the foil when the foil is fully inflated.. If not,
trim down the elevator more... These servos need to be EXTRA STRONG because
they are supporting the foil 100% of the time. I recommend the highest torque servos
available.. Speed is no concern, Slow servos are just PERFECT compared to fast
servos.

This acts like FLAPs and makes your foil give more lift.. by slowing the
air bleeding away from under the foil.

Battery is strapped with releasable cable tie, forward so that pod is head heavy

Plug up all holes with hot glue

Flying The Model

On Full power takeoff, the Kontronik Speed Controller may suddenly cut off because of overamps..
in which case you need to be very careful and use 80% throttle, or bleed off the power for 30 seconds
at 80% power before attempting your first flight.. I will be DISABLING the over amp protection
for my controller since the controller is exposed to open air anyway..

Transmitter Settings:

Ailerons -

Elevator - No change, Full rate

1) WITHOUT attaching the foil, check the pod for correct tracking. The pod MUST track straight forward
when power is applied

2) Check the servos for equal travel

3) Check the servos to make sure the horn is NOT frayed or LOOSE

4) Attach the foil and use tension to brush back the foil and the steering lines through the collars

5) FACE the foil into the wind, at this time the foil may catch the wind, check to make sure
the foil is not swinging toward the left or right, if it is doing this, trim the alierons trim so it swings
back toward the center (neutral) when it faces the wind directly. This means you have shortened
one steering line by too much.

Underside of the foil must face upward

6) If the POD tumbles upward and raises its front wheel, the battery must be shifted forward

7) Best position for electric is when the pod is hanging head heavy by 10 degrees or more when it is
held by the hang point clevis

8) Check the radio to ensure all trim settings are neutral or set properly

9) Ensure you have a long runway ahead of you

10) Power up slowly and when the pod starts to roll, apply full power

11) The foil will lift upward and you should track straight

12) If you track left or right, ABORT immediately

13) If you aborted ,trim the alieron so that it will track straight.

14) On take off roll , the foil must track straight, it will then lift off

15) A different ball game is now activated

Flying Symptons and corrections

A) On take off if the pod starts to swing left and right --

B) The elevator trim is used to determine the amount of flap in the foil
it all depends on the wind condition.. Too much wind and the foil will
rock left and right , you then know you need to reduce throttle or bleed off
air from the bottom of the foil.

When flying at cruise settings, you can simply turn into the wind and reduce throttle
and the model will land itself. Downwind landings are also done the same way
but results in a harder landing.

Flaring during landing requires airspeed. You trim the elevator trim up to bleed off
air and you chop the throttle at height. Turn into the wind and steer level to the
target landing spot. When 4 feet above the ground, GRADUALLY APPLY FULL
ELEVATOR. The foil will catch the air..

Estimated: Watts: 400+ Prop Watts, @ 42 amps

Cruise time - 8 to 10 mins on light wind day, 5 mins on heavy wind day.

MPEG MOVIES


ROG - 352k	Downwind landing - 224k

Check out : http://www.airfoilaviation.com/ for the products..

Conclusion

So far, I have explained the modifications necessary to do a direct E-Conversion of the Foil
AFTER the GAS version of the model has been built..

If you have NOT YET BUILD the POD, these are the necessary things you need to do to improve
performance of the model. Apart from all the other modifications listed previously the follow is additional
and will allow the model to behave more like what it has been designed for.