Bradley Fretwell reviews FMS' 64mm EDF jet - 20/5/11
Speed, that’s one of the most noticeable things about this model, and I don’t just mean in the air. This truly is an ARTF. It took me just one evening to build - the longest part of this was waiting for the epoxy (included in the kit) to dry.
So what’s in the box? Surprisingly almost everything you need; there’s a three-cell Li-Po, 12v balance charger, all the servos pre-installed, motor and fan unit along with the ESC all installed. All you need is to add your own receiver and transmitter, which frankly most modellers that would be looking at this type of outfit should already have.
The airframe itself comes out of the box in three main parts, the fuselage, wings and the tailplane. And it’s just a simple job of gluing these in place. When attaching the wings you don’t even need to support them, as the tight fitting lugs do this for you. After a ten-minute wait for the glue to be sufficiently dry to allow me to work on the tailplane, I moved on. I found this was just as quick and easy as the wings but you do have to watch that you have the fin straight and that it stays straight whilst waiting for the glue to set.
After completing the construction I discovered that the base of this model is held on by magnets, and therefore removable. This has to be my favorite feature as it allows access to everything, which on a model of this type is quite rare. When this belly pan is removed you are left looking at the fan unit, motor controller, elevator servos and all wiring. This makes any changes or replacements not only easier but also more feasible than in other foam-molded models.
Connecting the push rods for the elevators couldn’t have been easier. After locating them in the hardware pack, which only contained these push rods, two spare clevices and control horns, I connected them up. No adjustment of the clevice and the push rod length was necessary and I didn’t even need to drill the holes out in the servo arms, as this is already done and the z-bend slipped in a breeze.
Now time to set the C of G. Or rather just to check if it was correct, and it was perfect. Exactly 66mm back from the leading edge as recommended.
Finally, all I had left to complete this model was to set up the recommend control throws. Surprisingly, the movements were already correct. All I did was add dual rates to give myself the option of more movement if I needed it. I decided that, instead of using the 30% of exponential that the instructions recommend, I would go for a smaller and more acceptable ten, for now.
After waiting for the weather to become suitable, I charged the battery using the included charger, a particularly timely process, and we then headed down to the model flying club to fly and photograph the model for the first time. Having never flown an EDF before I was looking forward to this.
As this model doesn’t have an undercarriage our launch method would be a good throw, after facing into the wind and a few running steps, the model was in the air. This is when I began to realise some serious point about this model, and I suspect all models of this type and size, you can’t fly it slow.
Just after the launch, with no air speed and no prop wash over the controls, things can get a little hairy if it’s not launched well or when trying to keep it slow, as I did to make photographing it easier. It felt as if I was trying to balance the model on a pinhead.
When returning to my home club, our small strip located in the Kent Gliding Club field I had all the space I could ever want to play with this model, and that’s exactly what I did. Another hand launch and another flight, this time I told myself I was going to fly it in a smaller space, as the small size and grey colour scheme makes it very difficult to see when it gets over a certain distance away. So much so that, on a few occasions, I could have sworn I would be taking it home in pieces.
Thankfully however, its benign characteristics allowed me to predict how it would continue to respond until I knew for certain what it was doing.
Up and down the runway with turn-around maneuvers at each end, and keep it faster. I came to the conclusion that I wouldn’t fly this model around normally at less than half throttle, this gives you plenty of control authority, however this only gives you three or four minutes flying time on the 1300mah battery.
Time once again to land, and you only really have one attempt at this because it takes a while for the 64mm fan unit to get the model moving again, but one attempt is all you need. Flying the downwind and base leg on about half power, and then lining it up along the runway with my final turn I completely closed the throttle and committed myself to landing. Thankfully I had pushed my base leg right down wind; otherwise it would have sailed right past me.
I once again charged the battery, however this time on my own balance charger. Unfortunately the battery pack says not to charge above half ‘C’ charge rate, this did little to the time it took to charge, so after another timely wait it took to the air again.
This time I decided to explore the aerobatic capabilities of this model. As I had already had a go at turn around maneuvers I started with these. Just a few basics such as a split-s, it handled this well, flying the inverted sections just as well as normal flight, however through vertical lines it suffered and would tend to veer off to one side with the lack or a rudder stopping this from being corrected. After finding this out I decided how well it would cope with some loops of varying size. The first, relatively small, loop went without difficulty. The second, a large one, this went horribly. After a gradual dive to gain speed I began to pull up and the model began to swerve left, more and more to the point that it was now traveling at 90-degrees to its original heading. At this point I gave up. Maybe I’ll try again on a calmer day.
Another weekend, and another trip to the field. A bit of a breeze in the morning but I was confidant that the F-16 could handle it well, and it did. It does make things a little bumpier, and any fancy fly-pasts were raised up by at least a few feet, however it does make hand launching al lot easier, and slowing the model down easier for landing so this time it was right at my feet and perfectly controlled. After taking a break from model flying during the day to do some full size gliding it gave the wind a chance to calm and once again time for another flight.
This time I decided to play with the settings on the transmitter. Starting with the control movement. I feel that low rate for all controls is perfect, the recommended throws are spot on, and I don’t feel you should really want any more elevator. Next on the agenda would be the exponential. The only time this would really play a part with this model is when you’re flying it fast and even more important when it’s fast and low. Which for me was most of the time. As I mentioned earlier I made the decision not to use the recommended value of 30% and instead went for 10%. This was not quite enough but I still believe that 30% is too much, and I'm now flying it on 15%.
For me this model is great to have sitting ready to go in the back of the car. It looks good in the air. It flies so well, and it’s fast. All of this makes for a great package; however the lack or rudder really does hinder its overall performance. It would be easy to fit a servo to the rudder as it is already marked out on the fin. It’s also plausible to run the cables through to the receiver due to the base of the model pulling away; perhaps I will give this a go. But for now I’m going to continue to fly it at every opportunity I get.
Model type: EDF jet
UK distributor: CML Distribution
Wingspan: 20” (530mm)
Length: 32” (830mm)
All-up weight 1.01lb (500g)
Supplied with: Prefitted servos (4), 30 amp ESC, power system and 3S 1300mAh Li-Po battery.
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