Snap, Crackle & Roll!

This month I’m going to stand aside and hand the stage over to two truly remarkable pilots; a champion harking all the way from Israel, as well and a master of design much closer to home.

Those who read the last instalment of Snap, Crackle & Roll will know that the 2011 EXFC champion is a chap by the name of Ido Segev, a young Israeli freestyle pilot known the world over for his clean and fun routines that always fit the music like a glove. Prior to his success at last year’s EXFC he placed second at the 2009 event and third in the 2009 XFC, so there’s little doubt that this man is truly world class. Currently enrolled on a training course in Australia to become a full-size flying instructor, Ido kindly took some time out to answer a few questions...

Q. When did you start flying, and with what sort of models?

A. I began flying R/C at the age of five, following in the footsteps of my father and older brother, both passionate aeromodellers. My first aeroplane was a three-channel rudder / elevator design with a .15 glow engine up front.

A few times a week we ventured down to a deserted creek (I live in the desert), and with the aid of my father I slowly learnt how to fly; I have very many fond memories of those hot afternoons.

Having mastered the basics, things began to develop very rapidly. My father and brother wanted to build new models every week and were forever trying new things and exploring all corners of the hobby. As technology improved, so too did my flying ability and re-kitting aircraft became a less frequent event.

Q. What inspired you to get into radio control aerobatics?

A. My brother was the first to introduce me to aerobatics. When I started out, flyers like Chip Hyde and Quique Somenzini were amongst the best out there, and watching them was like seeing Houdini perform. The moment I clapped eyes on their flying, I knew aerobatics was what I wanted to do. I started out with simple profile aircraft, slowly progressing to 70” span models and eventually petrol aircraft. I now fly a 150cc petrol model, a progression that took around six years.

Q. What was your first proper competition like?

A. My first competition was a small freestyle show in the south of Israel in 2004. About 15 pilots took part, the models present ranging from small electrics to giant scale. I competed with a Morris-Hobbies Top Cap profile design, powered by an O.S. 50SX engine. I loved this aeroplane! (A video clip of this competition is on YouTube: www.youtube.com/watch?v=PBvNu4p_Ju8).

Q. Tell us about your preparations for the EXFC 2011, and what it was like to finally win? 

A. The 2011 EXFC was probably the best event I’ve attended, but also the most difficult challenge I’ve ever faced. I lived far from my family throughout 2011, so practice and preparation was that much more challenging. Not having sufficient time to practice just piled on the pressure even more. As a full-time student my weekends were no longer free to fly R/C as I had to study as well. I only managed to practice my routine about 35 times, over three days, so I turned to the simulator to help me prepare. Flying on the sim’ has the added benefit of being able to try a variety of conditions and scenarios, such as practicing my routine in a heavy wind, or with an engine down on power.

I was overjoyed to come first in the EXFC after three days of very close competition between me and Gernot Bruckmann, especially as I’d only just been beaten to second place in 2009. To finally win was the realisation of one of my biggest dreams, and the occasion was sweetened further by my dad and brother being present during the event. In truth, I think that they were happier than me!

Q. You’ve developed a number of foamy designs for Telink that are proving very popular around the globe. What sort of work goes into their development? Is there anything new in the pipeline?

A. That’s right, for some years now I’ve been designing electric foamy models for Czech company Telink. I’ve been fortunate to have the chance to bring some of my ideas to life and create aircraft that I believe to be excellent tools for practicing IMAC or 3D without the need to splash out on expensive petrol-powered models. The designs came about from my vision of a small, unbreakable aerobat that flies as well as much bigger and more costly aircraft. Not too difficult to achieve, but it’s incredibly time-consuming.

When designing a model from scratch, I have in mind what particular area I want the aircraft to be strong in. It’s very hard, almost impossible, to design a plane that will excel in all areas, so it’s better to home in on one aspect before drawing up a CAD model.

After we have a rough idea of what the aircraft will look like, how big it will be and what aerofoils we’re going for, the computer model is drawn up. After this the files are sent away so that a CNC machine can reproduce the virtual design in EPP foam. The process is so quick; computer model to flying field can sometimes take only a few hours!

Flight testing of the initial prototype reveals how flexible the model is during high-speed or high-stress flying. Subsequent prototypes address any structural issues, and small tweaks are made here and there to continually improve and enhance the flying characteristics. It usually takes about four prototypes before we’re ready to go to final production.

The latest model from Telink is the 3DBuster, a full EPP foam 3D biplane that’s the best 3D model I’ve flown yet. It’s very aggressive and a real joy to fly. This aeroplane was designed from the ground up to be a 3D-only machine, and we’re very satisfied with the results.

Thank you, Ido, for giving us a glimpse into the mind of a freestyle maestro! To witness his expertise for yourself, log onto YouTube and stick Ido Segev in the search box; his flight from the 2011 EXFC is my favourite video to date (www.youtube.com/watch?v=cBjEDnwGKeY).

BELL ON THE BALL

Now, I can’t speak for everyone, but sometimes I get a little jaded with the airframes on offer in the freestyle world. There are hoards of the usual Extras, Yaks and Sukhois to be had, but not much that’s non-scale (in larger sizes, anyway). Above about two metre wingspan your options are severely limited. I know of the 50cc Capiche that Weston UK offers, but that’s about it. I’m not sure why this is? Maybe manufacturers are under the impression that everyone wants to compete only in scale aerobatics? Whatever the reason, it would be great to see some more non-scale aircraft in giant-scale sizes. By their very nature, scale designs have to more or less follow the lines of full scale aircraft, but pure freestyle designs don’t have these limitations since the designer is free to try and design the ultimate aircraft.

One chap who’s always pushed the boundaries in this regard is Martin Bell. Some of you may recall the name, as it was Martin who released one of his .50-size glow designs, the Stiletto, as a free plan in the October 2005 issue of RCM&E. As well as being an unconventional designer, Martin is also a brilliant pilot. He’s a little modest in this regard but the man’s interpretation of music and his repertoire of manoeuvres is right up there with the rest of the best in the UK. However, he prefers to lurk in the shadows and fly for his own enjoyment rather than strut his stuff at the shows. I asked Martin whether he could spare some of his valuable time for RCM&E readers, and he kindly obliged:

      

Q. Martin, would you mind describing some of your exploits, both past and present?

A. In my mid-teens I started getting a little bored with turning up at the field and flying the same old manoeuvres over and over again. I needed a challenge. Around that time I started visiting the Nationals and after witnessing the fun-fly event I boldly claimed to my clubmates that I could win it. Of course, they weren’t going to let me off the hook with that one, so a year later I flew in my first national competition and somehow managed to win my class! I was very modest and humble afterwards, naturally. 

Since that first event back in 2000, I’ve attended every fun-fly and have been fortunate enough to win Class 1 on four occasions. The best thing about the competition, though, apart from the great camaraderie, is the opportunity for designers to come up with weird and wonderful creations. I’ve so far competed with canards, flying wings and models with all-moving tails, some being more successful than others! However, the relative inexpense, ease of construction and low wing loading these types of model offer make them perfect for learning the basics of aircraft design.

As the trend for the ‘young dudes’ shifted from fun-fly to 3D / freestyle in the mid-2000s I found myself looking at the then-new RCM&E Freestyle Championships as my next challenge, and so set about looking for an airframe with which to compete.

Being at university at this time I was naturally reluctant to dip into my beer money reserves, so an expensive ARTF was off the cards. Instead, I decided to build a 50-size model, which ultimately led to the Stiletto design that featured as a free plan in RCM&E. In 2005 I used the model featured in the magazine to win the advanced class of the RCM&E Freestyle Champs. It was the first time I’d won a national competition with an own design and I have to admit I was pretty pleased with myself! It was becoming obvious, though, that the trend for freestyle aerobatics was towards the larger, petrol powered models and, as such, I set about designing a 50cc airframe. 

From the outset I decided to use CAD rather than pen and paper, and to design something that was deliberately different to all the Extras and Yaks that were becoming so common. Apart from being able to visualise things in three dimensions, CAD also gives the opportunity to produce considerably more complex and detailed designs, as seen on many of today’s laser-cut ARTFs. The prospect of cutting so many parts by hand wasn’t very appealing, and having already had a number of my designs CNC cut by Mike Checkley at Cutting Edge CAD / CAM, I chose to go this route again. 

I created a 3D CAD model over a period of approximately eight months, a process that was rewarding and maddening in equal measure! I started by creating a CAD-based solid model of the airframe, as if it were made out of solid wood, and then began the process of cutting up that model to create things like fuselage formers and wing ribs. Lastly came all of the detail design work, such as drawing lightening cut-outs and creating the tabs and slots for the interlocking structure. Once complete, each part from 3D space was taken and nested together in 2D, ready to be emailed off and magically turned into a router cutting program.

The excitement that built waiting for the parts to arrive in the post was tempered somewhat by the discovery of the inevitable design cock-up, but regardless of that, it was immensely satisfying to receive a box full of bits I’d previously only seen on the computer screen, and even more so to start fitting them together. My fuselage design consists of a box-like central section running the length of the model, onto which is glued the bottom, sides and tops of the formers. The interlocking nature of the design meant that the basic structure could be assembled entirely without glue.

The fact that I had to sheet the whole fuselage (including canopy), and that the shape itself was quite complex, meant that a lot of stringers were required. Sadly, I wasn’t clever enough during the design stage to be able to draw the way each stringer curves and twists through 3D space, so I had to notch each former manually during the build. In other words, I bodged it as I went along! Sheeting the fuselage and wing roots in 1/16” balsa would prove to be far and away the hardest part of the build, and certainly the one that involved the most swearing!

The rest of the design is fairly standard, save for the balsa cowling. The model pictured is actually Mk.II, as Mk.I was lost to an embarrassing design flaw: the wing tube end-stops weren’t strong enough and, unknown to me, I’d knocked one off when inserting the tube. This allowed the wing tube to migrate fully into the left-hand wing, and for the right-hand wing to part company during a snap roll. The 30 seconds following this were quite entertaining, and although I managed a knife-edge approach to the strip I was unable to prevent further damage on arrival. It did, however, provide a good excuse to take the lessons learnt from the prototype and develop Mk.II. 

All-in-all I’m pretty pleased with the result. Despite the construction method chosen for the fuselage the model is on par with any ARTF weight-wise and with its large wing area and control surfaces it’s a very capable 3D performer. Ironically the large wing area is also its main weakness, as it prevents the model from snapping cleanly and can be too floaty in windy conditions. These are minor details, however, as its main purpose (to look different and prove that own designs can still be competitive) was a success.

ON THAT BOMBSHELL...

(Sorry, Clarkson) ...It’s time to wrap up this instalment of Snap, Crackle and Roll. As always, if you have any 3D, freestyle or aerobatic related questions or queries, or perhaps you just want to chew the fat, feel free to fire an email my way: [email protected]

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