30/03/2014
Some photos from Colin of his new model- please see writeup aswell.
Putting together a Hybrid F3J Competition Model – Colin Paddon
Over the past few years I have campaigned a Cluster for a lot of my F3J competition flying. During this time it has notched up many high level competition wins for myself and others in the UK. Its always been my “Go To” plane when the wind gets up, ie most of the time here in the UK. However it is an excellent all rounder that really deserves more recognition on the world F3J stage than it gets. I have always thought, along with others, that the moment arm on the standard Cluster fuselage was a tad short and that the rudder was a little small in area. The short moment arm has since been addressed by Heino, producer of the Cluster who has introduced a longer moment arm fuselage but only so far in V Tail form, which for me, wasn’t the way I wanted to go. We are all hoping that Heino will be producing a 3.8m Cluster wing sometime in the near future too.
Whilst attending the European Championships in Turkey last year, a potential solution to both my own and Graham Wicks thoughts appeared in the form of a new beautifully made Spread Tow (ST) cross tail fuselage that was being produced by renowned TRNC flyer, Eser Kismer. The fuselage Eser produces is in fact an alternative for Nan’s own Xplorer fuselages which, of course, have a different wing section and mounting screw placement to the Cluster wing so some work to retrofit it would be necessary. Having seen the fuselage all the UK team immediately placed an order for one and then awaited delivery. After a short delay due to sorting out some logistical issues, the fuselages duly turned up in the UK courtesy of TNT. Courier costs spread between the three of us ended up being pretty reasonable all things considered.
Eser’s ST fuselages are light, small in cross section, extremely strong and look great! The fuselage came supplied with a nice carbon ballast tube which can accommodate up to approximately 700g of lead ballast if required. They come with a very novel servo tray/carrier which is completely pre-assembled in high quality laser cut ply and is designed to be held in place by a large single rear positioned bolt. I modified the servo carrier slightly to provide an additional fixing at the front for extra security. See pics.
We also bought matching spread tow tailplanes with the fuselages but it was obvious that it was designed/sized for 3.8/4m wings and therefore looked “wrong” with the smaller Cluster wing. Fortunately the existing Cluster tailplane was a good fit without modification to the new fuselage so it was decided to use this which looked absolutely “Right”. The pictures tell the whole story of how it was modified and ended up looking so nuff said.
The new Cluster wing being mated to the fuselage was Heino’s extra strong lay-up meaning that it can take anything you throw at it. Total AUW ended up at 1840g which meant that it had the potential to not only be a great windy weather model with ballasting but that it was light enough to be a good all rounder too. With some further modifications I have in mind I hope to get this AUW down to below 1800g .
A week or so later it was ready to fly. Of course, on the day, it was blowing a gale but as they were the very conditions the wing had shown itself to excel in, we went ahead. A full-on F3J Ober winch was duly set-up on the field and we were ready to go and go we did!
What can I say other than that the performance has exceeded all expectations. The on board testing vario confirmed that the average launch height ranged from 205 -215 mtrs without any “dialing in” or ballast being used. Pe*******on has improved with there being less fuselage cross sectional drag too. Ease of circling/thermal turning has without doubt also improved making it extremely easy to fly at distance. Stability/behaviour on tow is exemplary with its landing tracking/behaviour is first class.
The strength of the fuselage was fully tested out early on when for the first time in over 15 years I managed to get the towline hooked around the tailplane after a somewhat over exuberant launch dip/zoom. The plane ended up inverted despite my best efforts to untangle it whilst providing a great impression of a spinning falling leaf until it hit the ground flat pancake style from some height. Only damage was a small crack at the base of the fin where it meets the top of the fuselage which was easily fixed along with a minor cut line into one half of the tailplane’s leading edge, again easily fixed. Very annoying as it always seems to happen to brand new planes rather than old one’s. Why is that!
Although I may be a little biased being a designer myself, I think this has to be one of the prettiest looking models I have ever owned. Others can make up their own minds on this of course from the pictures.
In the coming weeks I will be fine tuning the models set-up to optimise performance.
Colin Paddon
26 March 2014
