After mothballing the Rogollo Wing Project, got an inspiration from BMBLB (forum member) for building a flying wing.So started one. In fact I was with him when he maidened his DivinityII last Sunday. It flew so well that I also wanted to build one.
The wing is based on DivinityII on RCGroups. Instead of printing the plans, drew them on 6mm biofoam sheets and cut out the 5 panels. The Kfm6 panels are at 50% and 25% of the cord.
Wing span is 48in, root cord at 14.5in, tip cord at 8in including elevon at 2.75in. Sweep is at 14.5in.
Good luck!!
Laminated 5 pieces of 6mm foam which were cut in the shape of a B2 bomber canopy. The four lwer pieces were hollowed out before lamination. After the fevicol had dried overnight, the outer surface was sanded to merge the edges of the five sheets. The end result is shown below.
A hole to match the profile of the canopy was cut out in the top twp Kfm panels. The conopy will be held in place with button magnets for easy access to the electronics.
To add stiffness to the wing, a 4mm carbon fifre rod was installed at the COG point. I had a few spare pieces of carbon fibre rods 3mm which I stuck parallel to the alevons. Another spare piece was attached near the motor mount.
To cut the slots beveled at 45 degrees, I used a triangular strip of balsa to act as a guide as its edge is sloped at 45degrees. Two swipes at the edges of the area to be hollowed out and a thin strip of biofoamn can then be easily be pulled out. The carbon rods were stuck in the slot using slow curing araldite and left to cure for the day.
Wanted to make this model for sometime but settled for an Alula lately. The Alula is complete minus the electronics for which I am waiting for the parcel from Hobbyking. Will be eagerly waiting for the results of this model before I start my build... Best wishes..
KFm 6.....fantastic Sir!!! And having seen your other builds, this one is going to be a stunner
Please could you share the weight of the foam wing alone with ailerons before and after taping?
a pic to show the triangle formers I used for better wire management.....
The weight after a dry fit including a 2200mah 3s battery, motor and esc, servos comes to 633gms. Assuming additional weight of receiver and glue for attaching the panels the final weight should be about 683gms which is 24.1oz. With a wing area of 516sq in (3.58sq ft) the wing loading works out to 6.73 oz /sq ft worst case about 7oz. So should be flyable :P
sir any paint work??
JK
@Subhashjk0508.
Yes, after the maiden. Will try out my airbrush.
Glued the five layers of the wing using Fevicol pur 1k. The glu dries within half an hour whereas regular fevicol would have taken days to dry on such a large synthetic surface. After drying trimmed the leading edge using and sanded it round.
Balsa evelons installed. Motor mounted with electronics. Attached magnets to the canopy. Now fins and landing skid left before maiden. ;D
Ready for maiden. Added fins and landing skid which was required for holding the model during takeoff. Today cloudy and intermitent rains.
Awesome! !!. All the best Sir
Will be watching for the maiden.
Add some colour stripes etc while waiting for weather ;D
While waiting to go out for the maiden, fibreglassed the leading edge and mid section of the trailing edge with a strip of very light fibre glass cloth. A little bit of sanding and some stripes on one section of the wing.. Need to hurryup with the maiden as we have entered the last week of the sweepstakes
Enjoy the maiden video. Thanks to Mr Bhavesh who stepped in as the test pilot.
https://www.youtube.com/watch?v=DJCTJVwy2TQ&feature=player_detailpage
Nice and steady Sir. Congrads.
I was eagerly waiting see the test pilots face expecting he will pose after the successful flight with the model. Missed it. Super flying Bhavesh. Clean launch too
Quote from: ashok baijal on September 02, 2015, 11:07:40 PM
Enjoy the maiden video.
https://www.youtube.com/watch?v=DJCTJVwy2TQ&feature=player_detailpage
....its a finely crafted plane and an opportunity to maiden it is both a privilege and a pleasure - my apologies for the bumpy landing !
....the partial glassing is a nice way of strengthening it with negligible weight penalty and I will use this method in my future builds.....so much to learn !
Quote from: sundaram on September 03, 2015, 12:16:31 AM
Nice and steady Sir. Congrads.
I was eagerly waiting see the test pilots face expecting he will pose after the successful flight with the model. Missed it. Super flying Bhavesh. Clean launch too
thank you !....was naturally tensed as it was for the SW !
...Mr.Photogenic poses with his Fenix on the SW thread here:
Added landing gear with steerable nose wheel and gave it a coat of paint with contrasting colours on the top and bottom surfaces. Awaiting a vist to the flying field to test out the new setup.
Wow. Looks like a spaceship!
A closeup of the interesting shock absorber in the steering pushrod perhaps...
Looks lovely now.... Good job on painting. Hey what paints did you use ??
Thanks Iyer. Closeup of the landing gear servo arm attached. Hope it will prevent damage to the servo.
Shobitji I used Fevicryl colours with a light final spray of fevicryl pearl paint on the upper surface.
Good I also use Fevicryl but I use paint brush.....