Built from fiberglass and balsa. The Fox glider is a fast and an exciting plane to fly.
Whether you like high-speed park flying, slope soaring or thermal searching, the Fox 1.5m is a versatile high-end glider that can take you there.
The Fox has plenty of room in the fuselage for a 1300mAh or bigger lipo and a 29mm diameter motor, allowing for a large number of motor power/size combinations. Servo sizes can be from 9~20gram and because the control surfaces move freely a light weight 9g servo is all thats needed for anything less than high-G maneuvers. For fast high-G flight we suggest a slightly stronger metal gear or 15g servo.
This glider will take around 4-5hrs to complete.
Be sure to install quality servos and components and always use an ESC rated higher than your motors max amp draw and never use cheap quality or damaged LiPo batteries.
Type: Fox Aerobatic Glider
Construction: (Fuse=Fiberglass) (Wings=Balsa & CF-Spar)
Motor: 29mm Diameter
Servo: 9~20g 32x12mm
ARF Weight: 480g (kit only)
Further to my review on this model, I have posted a video on the HK website which demonstrates the performance after modification. Just click on Videos above.Continued again
With the C of G at 25mm back from the leading edge, normal stalls are predictable and stable. Inverted, there is still a slight tendency to tip stall, but this is manageable - most inverted stalls are gentle.
Aileron movements are set at a maximum of 10mm in both directions with some expo. Much more than 10 mm results in aileron reversal which hinders recovery from the tip stall. I have used rates up to 15mm which give snappy rolls, but I switch to lower rates for normal flight, particularly at low speeds.
/- 8mm is adequate for elevator movement. You may wish to use aileron differential - I haven't.
I am using Turnigy 20/30C 2200mah 3S batteries - the set up pulls about 50amps max with a Turnigy plush 60 amp controller. Performance is "more than adequate" and well worth the effort to solve the problems. If you have CofG further back watch out for tip stalls.Continued
The main wing spar is 6mm carbon fibre tube and likely to break on a heavy landing - I suggest that you use a solid 6mm dia carbon fibre rod.
The spring which is provided to hold the wings in place is too flimsy and too long - I suggest that you use cable ties across the hooks.
Effect of some of the problems:
Down thrust, as suggested by some, may counter some of the effects of the negative tail plane incidence, but would seriously affect inverted performance. With the negative incidence, the model requires masses of down elevator to maintain level flight under power.
Even with the C of G at 25mm back from the leading edge, the model will tip stall as you reduce the airspeed. This tip stall is violent and it is difficult to recover from. (the suggested modifications below reduce the tendency to tip stall)
Ensure that the effective tail plane incidence is in line with the wing alignment pins and that the motor is also on the same line. To achieve this I built up the tail plane with a top surface at 3.5 deg to the wing. This results in zero effective incidence and only a slight tendency to climb under power. Inverted flight under power requires a small amount of down elevator. This will be trimmed out in later testing.
With the C of G at 25mm back from the leading edge, normal stalls are predictable and stable. Inverted, there is still aFOX Fibreglass 1.5m Glider Kit - SKU:FOXKIT
Once you've solved the design and manufacturing problems with this model you will really enjoy the performance, however I suspect that few will make it beyond the first flight.
The tail plane incidence as delivered is -3.5 deg relative to the wing - this is serious and should be corrected.
The ply mounting plates for the elevator servo and battery are too flimsy - replace with aluminium plates.
There are no instructions with the kit.
The Hobby King video suggests that the C of G should be 25mm back from the leading edge. Other comments suggest that the C of G should be 45 mm back from the leading edge. IT IS IMPORTANT TO AVOID TIP STALLING THAT THE C of G IS NO FURTHER BACK THAN 25mm FROM THE LE.
The Hobby King video recommends a Turnigy H2218 1860kv motor. This is an outrunner, and the power leads will be close to the moving rotor as installed. I would recommend reversing the motor and installing a new back plate further back from the bulkhead or using an inrunner. I have used a Turnigy 3536 1400kv with a 10X7 folding prop.
The wing alignment pins are short and difficult to set accurately - I suggest that you use longer carbon fibre rods which will pass through the fuselage and be self aligning .
The main wing spar is 6mm carbon fibre tube and likely to break on a heavy landing - I suggest that you use a solid 6mmdoes anyone know what diameter the CF spar is? mine snap and now its almost imposable to tell how big it was.does anyone know what diameter the CF spar is? mine snap and now its almost imposable to tell how big it was.Better gliders for the money. Needs so much work to get everything right and then still feels strange in the air. Ive flown for a long time but this one had inherent design flaws. Yes its cheap but between the elevator control pushrod issues, wing joiner access issues, rudder twist and elevator incidence probs (all ready documented), what is it really worth!Needs alot of work to make it fly even remotely well. Yes its cheap but the rudder angle is off, the elevator needs alot of attention (as noted previously) and regardless of how much i played with CG, and all other components it never felt right in the air. I modified the pushrod snake for the elevator but it still is difficult to make it work really well. I cut a hole out of the bottom of the fuselage under the joiner to help joining the two wing halves and i used the cut out part as a flap door. There are better gliders for the money needing much less work.ive put the plane together with modifications i did,nt use the two plastic servo covers i cut a slot in the balsa wood so the servo arms stick through and operate under the wing i had to do this because of that heavier wing. flies perfectly now.the hooks and the spring that come with this model are way to long so i cut the hooks shorter. cut them just above the first bend hold in a vice and with a hammer tap them around to make them shorter make sure there is enough sticking out for the spring to fit on them.
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