SIG Somethin’ EXTRA .  51 ½ inch span, SC52 2 stroke, 4 channels + flaps, finished with Oracover and Sola film. The box says ‘The design can be set up to fly as sedately as a trainer or switch to high rates and roll so quickly you can’t count them, perform violent snap rolls, enter upright or inverted spins with instant recovery confidence and while you’re at it, lay it on it’s side and knife edge into the next county’.

Though it is now available as ARTF, I bought the kit version. The reason being; I’ve already got plenty of flyable models and so I wanted a project – something to build during the winter months. I chose this manufacture because I’ve previously had 2 SIG models and am impressed with the quality and in addition, they’re a bit unusual – I haven’t noticed anyone else flying one. As mentioned, this model is also available in ARTF form. It looks like SIG first produced this as a kit in about 1999 and because it was so popular and presumably to satisfy the growing demand, they then also produced the ARTF version in the mid noughties. Looking at their catalogue there are several other models available in both formats. I think this says a lot about dedication to their calling and sheer enthusiasm.

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Anyway I see that they made some small changes to the airframe construction between the 1999 version and the later one, possibly as a result of feedback and / or to make factory production more efficient, but it’s useful to compare the two if you’re thinking about whether to modify something in the kit. Also, I see that the latter version now has a cowl.

The kit comes with good quality, cleanly and accurately laser cut ply and balsa parts, strip wood and sheets. There’s also a canopy, set of spats, engine bearers, undercarriage legs, axels, various bolts, threaded rod, linkages, hinges, control horns and a set of decals. Intriguingly since they supply all these ‘extra’ things it’s surprising there are no wheels or a fuel tank but no matter, I already had those in the spares draw. Finally of course there’s an excellent set of instructions and a very detailed set of rolled plans (so detailed in fact that you could build another without the kit!).

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If you follow the instructions to the letter, you’ll surely get it right. They’re so comprehensive and include lots of useful builders tips. I have to confess I made a few mistakes – not too serious but they just meant I had to double back to correct them. A few points to mention. This is a mid wing model, with wing joiner tube running through the fuselage. It’s vitally important, right from the off that you get everything aligned and true. There’s no way to correct a mistake with this if you don’t. The upper and lower surfaces of the wing, forward of the main spars are sheeted in 1/16th balsa. Towards the leading edge particularly it has to accommodate compound curves which is quite tough to achieve without cracking it. Also the canopy, whilst excellently formed, is a fiddle to fettle and fit – you need to ‘creep up on it’ as the instructions say. Trim a bit, try that and trim a bit more as necessary. A useful tip. I didn’t have any specialist glue to fix it to the balsa fairing but found a tube of balsa glue in the cupboard – goodness knows how old but it was still in good condition and did the job perfectly.

The next thing was to try it out. Well it certainly is lively if you want it to be. High rates scare me too much. It’s quite capable of doing everything I’ve tried so far and It’s urging me to try new details. It’s had a few ‘heavy’ landings and I’m pleased to say it’s robust enough not to have been damaged too seriously.

So there we have it. I thoroughly enjoyed building it and am pleased with the finished result. I’d recommend it to anyone who wants to improve from an intermediate standard.

Article Ref: https://sigmfg.com/collections/sig-kits/products/sig-somethin-extra-kit