FW6 (FireWorks from PCM.AT)
A new model out there, it promises high starts.
Wing area [dm˛]:
Wing loading [g/dm˛] :
Our long awaited new F3K model is born!
To meet the requirements of competition, we laid special attention to the increase of starting height. Main ideas of our concept are largely based on the theories of Gerald Taylor.
Our aim was, amongst others:
to minimize weight despite carbon construction
to minimize yaw inertia, which causes oscillation of the model after release and
- to maximize stiffness.
Our measures were:
- Reducing wingspan
Stiffer construction by full-core technology and lightest carbon fabrics
Asymmetric, smaller and thinner rudder
- Reducing cross-section of fuselage
As a welcome side effect FW6 is extremely compact and manoeuvrable. The carbon construction of all components also promises a high longevity.
CONCEPT - "high-starter"
Lower wingspan - why?
Due to the lower wingspan the yaw inertia is reduced (I=mr˛). Result is a faster stabilization during the starting phase as soon as the pilot has released the model.
The resulting advantage of more starting height is decisive in competition and can not be caught up during the rest of the flight. The better initial height allows scanning larger areas to find a lift. Therefore, the chance for finding thermals and prolonging the flight is higher.
In contrast to models with high aspect ratio lower span provides - in relation - more cross-sectional area of the wing. The resulting higher torsional stiffness in turn has a positive effect on the starting height.
The larger cross section also offers advantages in various detail solutions, such as the installation of the throwing peg. Thanks to thickness enforcing material, which creates additional weight, can be saved.
The smaller wingspan improves agility and therefore circling characteristics.
In contrast to models with high aspect ratio the FW6 has broader wingtips, which contributes significantly to a good-natured flight behavior. Simple re-centering and faster curve changes are possible without noticeable loss of altitude.
"Full-Core"- construdtion with rohacell - why?
For our new competition model, we deviate from the proven shell construction for the first time.
In this construction technology, the wing is completely made of rohacell. Just the outside surface is covered with carbon fiber.
With this building method the torsional stiffness of the FW6 wing is almost twice as high as of a comparable wing of our previous model FW5. We could verify this in appropriate tests. This stiffness again supports the starting height.
Since the stiffness of this design is based on the utilization of the volume body, the effect is better, the more compact the body is, or the smaller the aspect ratio ist. The cross-sectional area acts exponentially onto the torsional moment.
Full-core-construction means that the building material is distributed according to the volume and not the surface. This construction technology therefore favors the centering of the masses. Mass centering means less yaw inertia and therefore quicker stabilization of the model during start.
As the control surfaces are also built with full core they are very stiff. As a result the model can be controlled more precisely and ailerons will be less twisting.
Building with full core means that all reinforcing fibers are placed on the outside surface of the wing. There they are most effective. Overall, this building methode requires less fabric and resin. (In shell construction a part of the fabric is located on the inside of the supporting material, which is of a great disadvantage especially what concerns the stiffness of the control surfaces.)
Airfoil "Zone V2" - why?
After a long verifying process we came to the conclusion that this profile is still the best solution in total across the entire spectrum.
White crossbeams on the downside for optimal visibility.
As skin layer we use 26g or 39g IMS carbon non crimp fabric.
The gap covers are are made of adhesive tape glued into a prefabricated recess.
All hinges are designed as kevlar hinges.
The throwing peg is situated at the outer edge of the wingtip. By this, the lever arm is increased for optimal disc launch.
We offer special throwing pegs for left and right handers.
Ailerons are controlled by levers and push rods, servos are located inside the fuselage.
We reduced the cross-section of the fuselage in comparison to FW5. Due to the resulting lower resistance the dynamics is maintained longer during the launch up to the maximum height.
Thanks to the reduced mass inertia of the wing the fuselage can be shorter than with our previous models both in the front and the rear, which in turn results in a reduction of the yaw inertia.
The fuselage of the FW6 is manufactured as FW5 in proven shell construction with balsa as supporting material. This design enables high strength.
We use high modular UD-carbon fibre for high stiffness.
The slide-on canopy provides accessibility to the servo board from both sides. The space can be exploited better, the installation of the electronic components is easier.
The servos are mounted on the radio board with screws. So servos can be changed easily..
The ballast tube allows simple loading of up to 70g.
The fuselage cone is made of kevlar to provide receipt of 2,4GHz.
The pylon for the horizontal stabilizer is made in one piece with the fuselage. The horizontal stabilzer is mounted with two nylon screws.
All screw connections are prefabricated.
We decided on an asymmetric rudder. Watching pilots with good throwing technique, the first swinging out of the model after release is clearly visible in slow motion analysis. The subsequent movement in the opposite direction oscillation is already weakened significantly. The asymmetric rudder acts primarily against the first oscillation.
Having a thickness of 6% the rudder of FW6 is considerably thinner than that of the FW5 and enables higher starts due to less resistance.
Because of the lower inertia of the model, the stabs may be smaller and thus contributes in turn to the reduction of inertia.
The stabilizers are also produced in full-core design. The benefits have already been explained at the wing and apply analogously for the tails.
For the skin we use 26g IMS carbon non crimp fabric. For the first time we can offer extremely robust, stiff and at the same light weight stabs for our DLG.
A special shaping of the rudder enables an easy installation of the vertical stab.
All hinges are designed as kevlar hinges.
ACCESSORIES (not included in kit)
4 pieces of GP NiMH Accu 35AAAH are ideal for the power supply.
Protection bags for the wing
Shell construction, with balsa as supporting material and HM-UD-carbon or kevlar in the cone as outer skin.
Full-core-construction with rohacell as core and 26g or 39g IMS carbon non crimp fabric as outer skin.
Spar booms made of high modular carbon tapes / shear web made of balsa planked with glass
Hinges made of kevlar
Gap sealing of ailerons with adhesive
Full-core-construction with rohacell as core and 26g carbon non crimp fabric as outer skin
Hinges made of kevlar
Ailerons are cut
Gap sealing of ailerons with adhesive
Screw mounting for wing and elevator is pre-fabricated
Openings in fuselage are cut, fitting of rudder is pre-fabricated
Kitparts (radio board, pushrods, levers, ballast etc.) are included in kit
CFK-stabs completely prefabricated apart from mounting the lever and torsion wire
The building instruction can soon be downloaded from the website.
It would be interesting to measure the moment of inertia of the FW 6 against a Snipe, Fr3ak Nxt, etc. Drela published an experimental method to measure it.
But it is nice to see again a well made Zone foiled model on the market. And some like them skinny, some like them fat, so it is all good.
I like their thinking with the shorter span. I get what they're going for, trying to achieve the XX/Snipe launch heights without the nasty habits these high AR designs can have. The skinny wings have their niche, but they're not all-arounder's like conventional shapes are and I think this is an attempt to merge the two performance ranges. It's an interesting theory, I'll be watching eagerly to see how it works out.
I know I'm far from an officiating voice with PCM, but I have over a year on my FW5's and know them inside and out now and I think they could stay plenty competitive with just a few mods to the current design. A FW5.2 if you will. A solid core wing, conventional tails, and kevlar hinges would basically make it about as perfect as it could be. Don't even change the foil. I've come to prefer the Zone V1 foils over the V2 because I personally think they are higher performance and can range better, granted they are not as user friendly. GT has agreed with me on that sentiment as well, and also on preferring the V1's performance characteristics at times. But this is pretty much again all personal preference
Ok enough flaming for now, still watching with interest.
It is an interesting question how far the peg is allowed to stick out:
Per section 22.214.171.124. of the current FAI F3K rules, maximum wingspan is 1500mm and the peg must be within the "half-span of the wing".
If Halfspan thus is 750mm, then you could let it stick out 30mm.
If you just obey the 1500mm span rule (as observed at the ILHGF) and not care about the half span rule, you could let it stick out 60mm! That would be a long T-blade.
PS: I am a bit confused by the FAI half span rule though. If half span is defined on the actual wing (i.e. Snipe having 1490mm span or something), then you would not be allowed to let it stick out at all. Most let it stick out a bit just within 1500mm.
Joined Oct 2003
Shorter span better?
I was going down that shorter wingspan path for a while. "Major Tom" was a 40 inch super stiff launch monster I made many years ago now for the 1 meter competition class that never really took off. I found, much to my surprise, that it clearly launched higher than the 60 inch version, but the glide and sink rate was so much poorer that it could not compete with the 60 inch models in a real contest. I did think I was on to something. Think about baseball bats; the legal limit is much longer than what the pros bat with. Simplistically thinking a longer bat should give more speed at the tip for hitting the ball further, but no, the pros have better results with a shorter bat (perhaps because they can accelerate it better) so why not a similar situation for getting the best launch speed out of a DLG.
My next experiment was to cut down a Fireworks 3 wing to 50 inches. I left the boom the same length but made the tails appropriately smaller. My hope was to get a higher than normal launch as the 40 incher did for me, but get closer to the good glide and float of the 60 inch planes. Yes and yes, it did these things finding a middle ground between the characteristics of the 40 and 60 inch planes, but still as an overall conclusion it could not quite beat the overall potential of the 60 inch planes. That is when I abandoned the idea.
So I read the new Fireworks 6 did not cut out nearly as much span as I did when I went down to 50 inches. Maybe they found the sweet spot...
I totally agree, the Flow is fantastic!
One of the best models I've flown to date!
The handling, range, float and air signaling is fantastic. All that is needed to make the design current for another 3 or 4 years is a solid core wing and a different tail (conventional)
As for the new design, like Reto, I'm not sold on the shorter span. These designs are very sensitive to span...
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