FPV49 build thread
The FPV49 is a scratch built RC deltawing designed to carry an on board live video system as well as an on board HD camera.
FPV49 uses Kline-Fogleman airfoils also known as KF or KFm (modified) airfoils. Unlike traditional airfoils the KFm has one or more steps induced along the length of the wing. Behind the step a vortex is formed which becomes an adaptive part of the airfoil with low friction. The KFm will give the plane a very mild stall curve and in my experience dampen vibrations due to “un-clean air”. I, like many others have found that the KFm performs very well when flying in the wind. The biggest drawback in my experience is that there is some drag compared to “standard airfoils”. However in my opinion this is a small price to pay considering the stability of the adaptive airfoil.
To learn more about the Kline-Fogleman airfoils please check out the following links:
The plane design is heavily inspired by both Schraut5 and rctestflight. Compared to Schraut5’s FPV40 and rctestflight minizephyr the FPV49 has less sweep as one can see on the illustration.
Since FPV49 is designed to carry FPV equipment it needs to have most of its payload in the nose section of the plane. Center of Gravity is about 24cm from the nose. If you fly with a tail heavy FPV49 you will have a hard time to control it, so put that weight in the nose.
- Wingspan: approx. 49 inches
- Weigh 1 to 2Kg (depending on your electronics)
Plane Typical Building Material/Tools:
- Depron foamboard (but most types of foam will work just fine)
- Packing tape (tapebrothers.com)
- Control Horns (or popsicle sticks etc)
- 3x Carbon Strip (8mm ish recommended for main fuselage)
- UHU Por glue or other foam friendly glue (woodglue works, but takes a long time to dry properly)
- Hotglue! But be careful it can melt depron
- Pushrods (or stiff metal string)
- 2x Carbon strip (6mm ish for elevons) (you can drop this if you don’t plan to fly fast)
- Battery bay made out of plywood or similar
- Camera bay made out of plywood or similar
- Coroplast for hatch/winglets
Plans for FPV49v1, 2 & 3:
I strongly propose to laminate your FPV49 with packing tape in order to reinforce the construction. Depron can easily break in a crash, but once depron is laminated with packing tape it is almost indestructible. Use the same method as Ed from Experimental Airlines to cover the plane.
This version is the first one I made in the FPV49 series. It is very light and flies really slow. It has a KFm-2 arifoil, but it could just as easy have a KFm-4 with one 6mm step at the top and bottom.
Of all the planes I have tried this is the simplest one to fly since it is so slow. The drawback with this one is that it may flex a little due to it’s light/thin construction. If you are new to large wings this is the best one to start with. It is also very nice for Line Of Sight flying.
With this plane I would recommend to make real large winglets to make it even more slow and steady :)
Use one C sheet and two A sheets.
This version is just like the FPV49v1 only with double thickness of the main body. The extra thickness makes the plane more solid and less open to vibrations and thus better suited for high quality areal video.
Use one C sheet, one D sheet and two A sheets.
For advanced FPV fliers. I made this plane to take the FPV experience to the next level, it can be build light, but for my purposes I wanted a strong reinforced wing that could handle greater speed and give rock solid video. It is reinforced with more/thicker carbon spars or rods and uses plywood battery and camera bays to reinforce the plane and protect the equipment better. Because this is build for more speed it uses symmetrical KFm airfoils like KFm-4, but KFm-7 is also a good candidate for this wing. I use a bigger motor and ESC and load it up with two 3cell 2650mAh batteries.
Use one C sheet, one D sheet, two B sheets and two A sheets.
KFm-4 fluid simulation:
(watch in HD)
Oh yes it has been built and plans will be posted here as soon as I have perfected it!
Flies pretty good:
I use one or two 3 cell batteries that power everything for all my setups. This is simple but the drawback may be that you have to put some effort into reducing noise from motor/esc so it doesn’t interfere with the video system.
I normally place the video transmitter on one wingtip and the radio receiver on the other. Ferrite rings are used on cables going along the fuselage to reduce unwanted noise.
Ferrite rings on control cable connected to the ESC is a must! Use ferrites on video cables as well.
I normally use a separate UBEC to power the radio receiver instead of feeding it via the ESC. If you do the same you can cut the + and – cable from the ESC and only use the signal cable (white) between the rx and the ESC.
Live video camera:
I use a 600TLV Sony Super HAD II camera with 2.8mm lens.
To me the most important thing is not to have “realistic” colors in the live video, but rather to be able to see as much as possible due to safety reasons. The Super HAD II camera is very good for this purpose.
I prefer a smaller lens like 2.8 to the 3.6 simply because 2.8 give a wider field of view. Flying with bigger lenses feels like flying while looking through a binocular to me. :)
Motor: 1400KV / 88,3gram / 420W
Prop: 9x6 / 10x6 / 11x6 ish
NTM Prop Drive Series 35-42A 1250Kv 500W:
(or something like this)
OMA-3820-1200 (.25 Size)
Or maybe something bigger:
Battery: 3cell (11.1V) 2650mAh (25-50C) (when using GoPro) // 4000mAh 3cell without GoPro
2 x 32 gram ie: DS329MG:
Electronic wiring diagram:
Don’t want to ruin the plane on the first launch?
Check out the How to launch the plane properly video:
Do not side toss it like you would a lighter and smaller plane. You have been warned :)
Some videos taken from FPV49
If you have suggestions to improvement or alternative electronics please let me know :)
The next step:
- UNDER CONSTRUCTION -