This has turned out to be a really nice plane. Zooming around and flat spins are its speciality. It's cheap and easy to build and fix so you never feel intimidated by it. Roll rates are more than I can handle. Even TonyS "I'll never fly electrics" never gave my model back! With lighter setups it is reasonably quick and entertaining and very forgiving at low speeds. Slow high-alpha passes are great, as is the DavidS 'Wall' stunt. With higher power levels, Peter burns holes in the sky although the extra weight removes some of its low speed strengths. The smaller 'Rafs' are just as impressive as Raf600 and fly pretty well in wind. A conservative CG is indicated on the plans.
Plans are provided for various sizes and materials:
1. Raf600B - 600mm span, simple airfoil wing, balsa fuz, either a CDRom motor/3S 500-1000mAhr lipo/7x5 APCe or double that with say 1000-1300 lipo, 9g servos (L'Original version).
2. Raf600E - As per 'B' (balsa) version but this has an 'E' (EPP) fuz; less stiff so only suits CDRom power.
3. Raf400 - 400mm span, flat sheet wing, 6mm EPP fuz, 10g 2000Kv motor, Gunther prop, 2S 300mAh lipo, 3.7g servos ('Fox' version)
4. Raf340 - 340mm span, flat sheet wing, 3mm EPP fuz, 5g 2000Kv motor, 4x2.5 prop, 2S 150mAh lipo, 2.5g servos, 43g AUW
5. Raf1000 - 1000mm span, (PeterW WIP)
6. Raf280(?) - 2g brushless, 1S lipo, 1.7g servos
Raf600 - CDRom motor
I will mainly describe Raf600B with the balsa fuz. The others are very similar. The wing comprises four 3mm depron triangles. The outer two form the skin and the inner two simply create an airfoil shape. Just tack them together. No spar is required and the wing is built flat initially as a 4 layer sandwich. A symetrical airfoil is then created by gluing the leading edges with contact adhesive such as UHU POR with their outer edges rounded with a sanding block. Flappy bits are 6mm depron. 9g servos are glued into the wing. Align the elevator with the bottom of the wing to give the wing the required reflex shape. The 'side on' photo of the wing above shows two wings, the lower in it's flat state, and the upper with the leading edge glued together and sanded slightly.
The fuz is 3mm balsa. The rear section from behind the canard is intended to be built first, upside down. This should help you get at least that part straight. Some dummy balsa formers are placed on either side of the canard/hatch opening allowing you to pull the nose together around them and then sheet the rest of the bottom and nose. Remove the formers once done. Nothing is critical; you are just trying to make a simple box fuz so make up your own technique if you prefer.
I use a cheap single CDRom motor such as the 1500KV Blue Wonder with an APCe 7x5, a 3S 800-1000mAH lipo and cheap 12-20A ESC. Double the motor size with perhaps a 1300mAh for more speed. I normally put my ESC near the front and lengthen the 3 wires to the motor. Abrupt landings can unplug the ESC wires from the motor at the back. This is 'good' because you don't want to rip the wires out of the motor. So a hatch is made in the bottom at the back for access. However, I also put a bamboo skewer through the sides of the fuz and secure the ESC wires to that with tape or cable tie to reduce the likelihood of disconnects. With a light motor some of the wing may need to be cut away for the battery. With a heavy motor, the fuz is deliberatly quite bulbous to allow the battery to be further forward.
The canard definitely improves flying characteristics. One photo shows how I used a tongue in the front and a sliding wire catch at the back to hold the canard on. However, I now have a tongue at the back and a magnet at the front to improve 'leverage'. PeterW has a balsa or foam canopy and uses a tongue in the front and a magnet right at the back of the canopy. The fin is 3mm balsa or 6mm depron.
Objective is to make them more resilent to knocks. Landing from the flat spin is fun but can crack a balsa fuz. Depron is still used for the flying surfaces because it is stiffer and looks better than EPP. Pretty much the same construction as above. However, because the EPP fuz is very flexible I glued the fuz to the wing along its whole length of the slot in the fuz, top and bottom. This is mostly easily done by cutting the fuz open as shown in the last photo above. The catch on my smallest is two pieces of 1/64 ply to 'trap' the depron canard to hold it in place. Another option might be to glue the canard to the fuz and make a hatch in the bottom.
Free plans are provided. As usual you may build the model but may not profit from the design. Check your printer settings (don't 'fit to paper') to avoid distorting the size. Let me know if you have any queries.
Art of the Possible ¦
Absence of Matter ¦