In some ways I’ve wondered why E-flite's new ultra micro release has arrived at the tail end of the indoor flying season. The 17” span (432mm) machine looks to sit firmly in the ‘indoor’ category at first glance although closer inspection and flying experience points to a model, like their UMX Pitts, that’s really more at home outside and indoors only in the very largest of halls.
Actually, that’s a lie, I‘ve seen the Pitts flown expertly in smaller halls but only the highly skilled or reckless need apply if space is tight. Not that you need to be an expert to fly models like this outside, far from it and the good news is that, with care, this Sbach is nicer through the slow speed range than the UMX Pitts.
So what do we have then? Well it’s a four-channel aerobat, moulded using EPS foam and blessed with a powerful motor system. It’s a pretty little thing too – finished in a scale colour scheme with attention to detail that we've come to exepect from the brand. With a profiled symmetrical cross section and huge control surfaces you’d think it’ll do just about anything but, as designer Mike McConville concedes on the recent Horizon podcast, it’s not really a 3D machine, more, a freestyle aerobat. It takes some aerodynamic cues from much larger R/C machines so the wing offers slightly thicker tips to help slow speed flight.
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At the pointy end, thrust is provided by a tiny E-flite 2500Kv outrunner swinging a custom-designed 5 x 2.75 prop with power from a 20C, 180mAh 2S Li-Po battery. The model is pre-fitted with a DSM based Spectrum AR6400NBL receiver/ESC which differs to previous units in being completely separate from servos. It means that the tiny AS2000L long reach servos can be sited anywhere and in so doing provide more precise control to the moving surfaces.
The model is supplied as a Bind'n'Fly (BNF) machine, and, with a battery and charger in the box, binding to a DSM radio is all that’s required. Actually, there’s a little more than that and, a manual of the sort that other manufacturers would do well to emulate, guides starting control throws, C of G placement and SFG installation.
SFG? Side force generators – the wing mounted fins that help to improve rudder authority. Two sets are supplied, one larger than the other so giving the pilot more options as to optimum set up.
I’m a bit of a rebel where it comes to RTF models and C of G these days and, on the basis that ready-to-fly manufacturers (who supply a battery) really aren’t doing their job properly if the model needs some sort of C of G adjustment, simply fit the battery and fly. If the C of G is out to lunch then the model clearly hasn’t been tested by the makers – RTF means RTF surely not?
That’s all very well but it’s an attitude that can lead to disaster so I’m choosy where it comes to such recklessness and know I’m on a safe bet when test flying a feather-weight machine from the Horizon stable. I was here too – in retrospect the model balances spot-on at 29mm in from the leading edge at the root. Just as well though – there’s no room to shove a battery around for adjustment but the pack sits happily just behind the motor, secured by Velcro and sealed by a cleverly designed magnetic cowl hatch. Charging the tiny cells is courtesy of a 12v input charger and takes 20-30 minutes – indicator LEDs reflect the status.
FLYING
A simple under-arm hand launch will see the model make a clean getwaway while, needless to say, ROG (rise off ground) needs a smooth surface. If you don’t start with the low rates then, well, you may wish you had – these are large control surfaces here that call for expo and/or dual rates. In truth, I can never be bothered with dual rates – I’ve seen too many models go ploughing into the ground while flyers fumble around for the switches – so I start with low rates and perhaps a little expo (the settings in the manual!) and go from there until I’ve got the model doing what I want it to – fly smooth with unagressive elevator response through normal flight but with the ability to go a bit wild when I start banging the sticks. Knife-edge, point rolls, spins, flicks and all regular aerobatic turns fall happily to place.
I'll not give a blow-by-blow account of every manouevre – mainly because the model doesn't need it – it's a very neutral little machine that faithfully reproduces in miniature what a larger capable aerobat will do. Like all models of this size (and despite what you may read) it needs a flat calm day really; it'll fly in a slight breeze but enjoyment is lessened.
And those SFG's? Well, yes, fit 'em if you must. I think they look horrible and completely destroy the appearance of this pretty model and you have to ask yourself what's the point? They'll help through a few manouevers perhaps but full size Sbach's don't have them so why buy this model only to ruin the appearance? If you can't live without them then you may as well buy a 3D shock flyer.
ALL-UP
I’ve found myself attracted more and more to the Sbach over this last couple of months. This rather fine little machine could quickly become last week’s news such is the rate of new releases we’re seeing at the moment but it’s imbued with qualities that push the ultra micro genre on a few notches and makes a fine yard/park/driveway aerobat – an aerobat with a repertoire akin to a far larger machine. Allow time to tweak and become acquainted and you'll soon start to appreciate its obvious abilities.
Indoor? Well, not really or at least not in the average small hall but certainly a capable pint sized aerobat to fly in your (large) garden this summer while the shrimps sizzle away on the BBQ.
DATAFILE
Name: UMX Sbach 342
Model type: Ultra micro aerobat
Manufactured by: E-flite
UK distributor: Horizon Hobby UK
RRP: £109.99
Wingspan: 17" (432mm)
Fuselage length: 16.6" (417mm)
All-up weight: 60g
Power system: E-flite 2500Kv outrunner, 5 x 2.75 prop, AR6400BL combined Rx/ESC unit, 2S 20C 180mAh Li-Po
Functions (servos): Ailerons (2), elevator (1), rudder (1), throttle via ESC
