This review was first published in RCM&E Jan 2004 and the kit is still available (see 'up to date' comments below).
The Filip 400 Light was reviewed in the 2008 Special Issue and can be viewed in the digital archive.
I’ve always tried to use kit reviews as a way of building and flying models that I wouldn’t perhaps, have bought on impulse at my local model shop. Call it a bit mercenary if you like, but for me the joy of reviewing a kit is building something a little removed from the worthy but everyday .40-size sport model.
Having said that, the Filip is a difficult model to categorise. Is it a hotliner? A powered soarer for flat field and slope? Perhaps a little of both – the instruction manual describes the Filip as an excellent slope glider which is also capable of thermal flying.
Distributed by Puffin Models in the UK, the Filip 600 Sport is produced in the Czech Republic and is available in T-tail or V-tail versions. The word ‘sport’ in the title means the model has a solid wing that provides the strength required to cope with aerobatics – although a standard version with built-up wings is also available. The model spans 1990mm, all-up weight is about 3 lb 12oz, wing loading is 17oz / sq. ft., and the wing section is SD7037.
Good old SD7037… er… yes, you probably think the same as me – the meaning of the number is lost on this common-or-garden flyer, but what is obvious is that the Filip has a thin wing designed for speed, and a beautiful wing it is too. I really mean that, the quality of this model is absolutely top notch. The Solarfilm covered wing halves are made from a foam core sandwiched between a liteply veneer, the V-tail is balsa sheet and the fuselage a superb one-piece fibre-glass moulding. The standard of construction and covering is superb throughout. All moving surfaces are pre-hinged, with a little bag of hardware bits and an instruction manual completing the contents.
Solid core wings and a fibre glass fus' mean it's very strong
What I also found in the kit box is something that I’ve never seen before in some 15 years of model kit reviews – a letter to me, the reviewer, from distributor Puffin Models. What a nice touch! However, it shouldn’t have come as a surprise. John and Sandra Emms at Puffin have been in business selling electric models and motors for a couple of years now, and during this time they have built up a good reputation for outstanding service to their customers. Those customers talk, and although I’ve never shopped at Puffin I’ve heard many flyers sing their praises. Now I’m sure John doesn’t have time to write to every customer, but it was clear from his letter that he’s pretty passionate about sharing his own experiences of flying the Filip 600, which, by the way, he later told me he numbers amongst his top five models of all time!
I spent a week or so talking to flying buddies, trawling internet reviews of the Filip 600 (there are some excellent write-ups on this model – just type Filip 600 into Google and you’ll see what I mean) and of course, I had a good chat with John.
The Filip is a practical design that can accommodate most speed 600 size motors from the basic ‘can’ unit, upwards. What’s obvious is that fitting a basic ‘can’ motor simply won’t do this design justice. Since this is a performance model that requires a 12 x 6” folding propeller to pull it around the sky, a ‘can’ motor just wouldn’t suitably turn a prop of this size without a gearbox, and there’s precious little room in the fuselage for one of those. At John’s recommendation I opted for an AXI 2820/10 brushless motor with a Graupner 12 x 6 folding Cam prop.
Power would be from a 10-cell 1700mAh CP NiCad pack. Actually, I rang John at Overlander to order my batteries and he thought I ought to try their 10-cell 2100mAh HR-SCU NiMH pack, so I got one of those too.
So far so good, now all I had to do was put the model together. John Emms made a point of telling me to take my time putting the Filip together. It’s good advice. Although the kit contents are high quality and there aren’t many bits in the box, this is a model that demands some thought as to where everything is going to go and how that will be achieved.
The Filip requires four servos. One mini servo in each wing and two micro servos for the ruddervators. I used Ripmax SD200s in the wings and Hitec 55s in the fuselage. By the way, you shouldn’t think about buying the Filip unless you’ve got a computer transmitter.
In this respect you’ll need v-tail mixing, flaperon mixing and aileron differential – all of which require the aforementioned Tx. Yes, I know you can buy plug-in mixers and the like, but what a lot of messing about.
Construction started with the wings, which require that boxes be cut out for the mini servos and extension leads be fed through using the pre-installed small tubes. This was a simple enough task, but I couldn’t quite see the point of facing off the area I had cut away. Given the narrowness of the wing, I simply cut away the foam inner until I reached the veneer on the top. Said veneer is a good 3mm thick and it was to this that I attached each servo. Each wing servo installation is covered by a neat, streamline hatch cover that hides away all the untidiness and protects the servo when landing.
The V-tail is cyano glued in place and although I was prepared to drill though and add some small screws for added security, on reflection this seemed unnecessary. One major variation from the instructions did take place here. In considering the radio installation it was apparent that the v-tail servos would need to share a pretty small space with the flight battery, speed controller, and receiver. Also, the control runs provided in the kit are thin snakes that would be difficult to secure along a narrow tubular fuselage, possibly resulting in sloppy ruddervator movement. Whilst pondering a solution I noticed that some of the guys who had reviewed the Filip for their internet sites had got round this by installing the servos in the fuselage itself at the point where it widens below the tail feathers.
Two Hitec 55s fit a treat, providing direct, slop-free movement to the control surfaces and freeing up a ton of space at the front. Needless to say, I did the same.
That was basically it as far as the building went. My AXI fitted a treat in the nose and I made sure the cables were free of the revolving rear-end of the motor by running them under the battery tray floor. The speed controller also went under the battery tray floor, with the receiver behind the battery. The battery floor was Velcro fastened in place and the battery attached to the floor via the same method.
I spent a good two hours carefully setting up the model – control throws, differential etc. It’s recommended that 50% differential is selected for the ailerons, and 30° flaperon. The AXI was tested in the garden and I don’t mind telling you I was very impressed with this smooth but incredibly powerful unit; it was time to fly the Filip and I couldn’t wait!
FLY FILIP FLY
The model simply roared off into the ether and I immediately throttled back to take stock. A little left aileron trim and some up-elevator soon had the aircraft flying perfectly but my mind was concentrating on two initial aspects of the Filip’s flight envelope. First, the slow speed check – the stall characteristics showed that the design really had to be pushed before a wing would drop and even then recovery was fast. I remember thinking, ‘good, I can cope with that’.
Secondly, I needed to get the Filip to a safe height before dialling in the spoilerons (both ailerons 30° up) to make sure that they didn’t have any adverse effect on the flying characteristics. Again, the model behaved impeccably and some speed reduction was evident.
The aircraft looked beautiful in the air and was exhibiting a good turn of speed with full throttle. I tried a quick loop before deciding to land and brought her round in a large circuit to let the speed bleed off before touch-down. Landing the Filip was easy – the spoilerons had helped slow her down and she simply flew herself in for a gentle arrival.
At this, I decided to take the model home for checking over and it was just as well I did as the tail surfaces had come a little unstuck during the flight. Some cyano soon put paid to that, but I made a mental note to keep an eye on the tail area after future flights. In addition, the speed controller was very warm so I moved it to a position where it would benefit from improved air-flow cooling.
Outing No.2 was a pure joy. The day was perfect – a beautiful windless autumn afternoon. The model was a delight to fly and just soared around in a big blue sky. My batteries were starting to get run-in by now and even without any thermal activity the aircraft put in flights of over fifteen minutes with power in reserve after landing. Needless to say I was a very happy chappy indeed.
I’ve built and flown many electric models, but each and every one has been powered by standard ‘can’ motors. In this respect I’m really glad I reviewed the Filip because aside from the model itself, my eyes have been opened to the benefits and sheer power that brushless motors can provide. It really is another world. Ha! Who needs glow motors?
Turning to the model itself, I can understand why John Emms is so excited about it. Make no mistake, it’s a quality aeroplane. In flight the model will assume the persona you give it. By this I mean that if you want to soar or try and catch thermals then you can. If you want to fly some big jet style aerobatics then you can do that too. Prefer to just power around and make low exciting passes followed by sharp pull-ups and wing-overs? Guess what? You can. If you want to take this model to the slope then you can, and if you want to take it to a flat field site then you can do this too. The Filip will do pretty much anything you ask of it and always look good in the air. I won’t waffle on with the superlatives other than to say that the Filip 600 Sport is a wonderful machine. I like it and I’m sure you will too.
2010 – LOOKING BACK
I gave my model away after a few years and have many times since regretted doing so to the extent that I may just have to buy another. I always flew the Filip from a flat field and, with my soaring hat on, the longest flight was approaching an hour but the model looked and sounded great in 'warmliner' mode just flashing past at speed.
My decision to place the V-tail servos where they were did elicit concerns from some that they would suffer knocks with a risk of stripping gears although I never had a problem. I would fit high torque (perhaps 2kg) metal gear units if doing the job now though.
That said, lighter (compared with NiMHs) Li-Po batteries may also demand that a little weight is added at the nose, something to be aware of and a factor that may dictate the V-tail servos are placed forward to reduce weight aft. The Filip series has gone on to garner a strong following over the years and still sell well, deservedly so.
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