|Mar 02, 2013, 01:11 PM|
Scratch built 63" FPV Wing "Hammerhead" Vids & Images
I just finished building my new 63" wing using a KFM2 airfoil.
Its main use will be fpv flying.
To form the wing I used white foam (k20). For the fuse I used blue heavier foam.
For reinforcing I used three carbon tubes forming an "A" inside the lower part of the white foam.
For extra strength I also embedded a wooden rod near the trailing edge.
I also installed thin wooden rods to form the leading edges and make them crash proof.
I pre- carved almost all of my bays before I glue the three layers of foam together using PU glue.
All of the reinforcing tubes were glued using 30min epoxy.
The elevons are made of two layers of 6mm depron glued together and then sanded to become curvy.
Top and bottom of the wing is monocoated.
The motor is a NTM 35-48 with a 12-6 folding graupner prop.
(Edit Apr-13. I replaced the motor with a bigger slower one: Lindiger (DualSky) 42x50 720kv and the prop with an APC 14x7).
The motor base is made using 4 solid PVC tube pieces. They are glued inside slots formed in the blue foam.
On the 4 PVC ends are installed the 4 screws that are on the "X" motor base.
(Edit Apr-13. I installed a wooden firewall treated with CA and then 30min epoxy).
(Edit Mar-14: I reinforced the motor base by adding 4 carbon tubes, 2 top+ 2 bottom, and I ziptied them together to compress the top and bottom part my wing)
I am using a plush 80A ESC and 2x2.200mah 3s lipos.
(Edit Apr-13. I am now using a 5.000mAh 4s zippy flightmax lipo).
(Edit Mar-14: moved on to 2X5.000 4S motor lipos and a 2.650 3S lipo to sustain the longer flight times and Hornet OSD munchies)
Fy31AP, Remzibi OSD, futaba full size servos,(Edit Apr-13: installed Futaba full size digital servos), 5A BEC, camera, FrSky telemetry Rx and 500mW 5,8Ghz VTX are powered through a separate 1.300mah lipo. (Edit Apr14: moved to 800mW 1258Mhz ReadyMadeRC VTx).
The frsky antennas are located by the left wingtip and the 5,8ghz Vtx by the right wingtip giving a total separation of 63".
In the videos you can see how easy is to hand launch it.
The inflight footage is of poor quality as it comes from my ground station DVR and its main purpose is plane recovery in case of an accident using
the OSD GPS coordinates that are shown in the lower part of the screen.
The total surface is more than 72dm2 and AUW is about 2.100gr including all fpv equipment.
(Edit Mar-14: not any more, the wing is waaay heavier now with a wing loading of (t.b.c).
The total wingspan is 160cm or 63".
Root cord is 60cm, tip chord is 30cm and the sweep is 30cm.
To achieve correct CG, I added the flat lipo tray in front of the nose that gave my wing its name.
The flat tray is attached to the wing in an angle making landings easier and constantly pushing the nose up during flight.
In the DVR footage you can see that I have an Artificial Horizon and RSSI percentage.
This was possible by connecting my OSD to the uart port of the FY31AP (thank you Remzibi).
For the RSSI, I hacked my FrSky Rx to get (+) signal from the green led. This signal was fed to the Remzibi Hall Sensor input and calibrated to appear correctly scaled from 0% to 100%.(Remzibi ROCKS!)
(Edit Mar-14: Added a Hornet OSD that I got on an ebay bargain).
The good thing is that the wing glides forever. It thermals easily and stalls like gliding. I Love KFM steps!!!
I am pretty sure that it will fly perfectly even by carrying twice the lipos I have installed if I wanted to. (Edit Mar-14: I was right)
For lipo monitoring I am using the OSD for voltages and two balance port sensors for audible independent cell monitoring of my motor and avionics lipos. It is easy to hear any alarms while flying through the vtx microphone. All you have to do is to cut to idle and pay attention.
I am very happy with my stepped Hammerhead and I would like to thank all the rcgroup members who helped me bring to life a dream of mine.
Have fun, fly safe.
|Mar 05, 2013, 09:15 AM|
the only drawback until now is that it takes a lot of space in my car for transportation.
But I really enjoy the fact that I don't have to assemble anything on field.
Plug in batteries, setup ground station and take off.
|Mar 20, 2013, 03:35 PM|
A few 1080p videos
hand launch and a vertical climb. I am now using 4s lipos.
today I was range testing my 1W boosted FrSky
A view of my GPS GSM locator.
|Apr 02, 2013, 12:38 AM|
Futaba digital servos installed:
Motor replaced with a bigger slower one, in order to use a 14" APC prop in replacement to my 12" Graupner folder:
I also installed a wooden firewall using PU liquid glue, because my old motor twisted the 4 pvc rods installed inside the dow fuse.
Flight testing is coming...
|Apr 06, 2013, 01:02 PM|
After seven flights I am pretty certain that the Lindinger motor is just right for my wing. Today I tested max flight time with one 5.000 4s lipo.
I was using a non folding APC prop 14x7 and my AUW was a bit over 2.200gr.
My cruising amperage was about 6,5 to 7,5Amps and I stayed on air for a little bit over 38 minutes.
I am happy with those figures and I really love the sound of the big prop pushing my wing.
Images will follow...
|Apr 07, 2013, 04:02 AM|
38min on a 5.000mah 4s
I think I could get a longer flight if I managed the throttle better.
The video is of bad quality and boring but,
the last minute shows two hawks flying with me in 720p...
(youtube ate my 5 last secs.....)
|Category||Thread||Thread Starter||Forum||Replies||Last Post|
|Sold||Scratch Built Flying Wing Giant 80" Wing Span RTF with Lipo||rhampton||Aircraft - Electric - Airplanes (FS/W)||2||Feb 12, 2013 05:15 AM|
|Build Log||Designing for scratch-built FPV wing...||PiperCub49||Flying Wings||15||Mar 09, 2012 09:15 PM|