имонтн є151 |

/ - WINTER FLOAT FLY

TROPIOI

FREE Spitfire instrument panell Breakout the glue and get building Plugs, connectors and batteries

WHEN AN ARTF MANUFACTURER TURNS TO PRODUCING BOXES OF PRE-CUT BALSA

YOU CAN BE SURE THERES LIFE IN THE TRADITIONAL SIDE OF THE HOBBY YET – DAD ASHBY BREAKS OUT THE BALSA CEMENT

Seagull has entered the kit market by releasing two self-build versions of existing ARTFs. The Other is a trainer

Everything youd expect from an ARTF is included, except the building and covering!

ARTFs are made then just cast an - eye over Seagulls Facebook page, where regular updates provide a fascinating glimpse of the production line. Alternatively, you can build this Challenger. Along with its Boomerang trainer this is the first traditional kit the company has produced and it reveals how ARTF models must be designed; not only for the end user, but from a production perspective, too. The girls making your ARTFs dont have time for plans and pins, so the models must be speedily

you want to know how your

assembled with no more

than a few simple jigs, bottles of cyano, and white glue.

This Challenger is an attractive, classically styled sport aerobat with more than a passing resemblance to Hangar s Pulse series. It isnt new — the ARTF version was introduced last year – but that hasnt stopped a number of retail websites tagging this kit version as being 61" (155cm) span. Matters havent been helped by a manual that does the same, but in fact this one spans 52.8" (1340mm), and is the same size as the ARTF. Is it suitable for firsttime

builders? Yes it is, although

the process wont be without a few niggles, which Ill come to, but theres nothing insurmountable here, indeed building the Challenger should be an enjoyable project.

Seagull produce a large range of well-made and affordable models but their instruction manuals arent the best, so I was curious too see how theyd manage to describe a construction process that needs a bit more guidance than they normally manage. Predictably, the answer is, not very well. Building starts with the wing, where the manual seems full of good intent, although a decline sets in when its time for the fuselage with some parts and processes being taken

words David --

photos y David Ashby / Graham Ashby

for granted or ignored. Comfort can be taken from the full-size plan thats included, but only a little as not all the parts are labelled on the plan, and some have been missed. Its nothing Id describe as critical, and the lasercut structure means that theres only one place where most parts will fit, but bear in mind that

head-scratching must be expected along the way.

Its a pretty comprehensive box of bits though, where, curiously, the liteply parts are individually labelled, separated from their frames and bundled up; one pile has the wing bits, and the other builds the fuselage... I suppose it reduces the size of the box. Alongside youll find the tail parts, dural uc, clear canopy, glass spats and cowl, large decal sheet, bottle of white glue, a brilliant permanent grit sanding block, an awful pilot figure and all the usual good hardware that Seagull include. Surprisingly, youll find that a little work has already been done, with the forward fuselage doublers and wing servo mounts in place, and the wing tips strengthened.

Power should be from a 40 or 46 twostroke or four-stroke equivalent, but they got a bit muddled where electric power is concerned. Although theres no mention of an EP option on the box, both the manual and plan describe outrunner installation, made practical thanks to a large canopy hatch, although the plan and manual state that motor standoff parts arent included, when in fact they are.

WING Seagull suggests assembling sections before adding cyano and then using the white glue to strengthen some of the joints, but with the glue supplied having an unhelpfully thick, porridge

like consistency I used cyano and my own aliphatic throughout.

The wing is a slottogether liteply structure with balsa leading and trailing edges and partial sheeting. It has a semisymmetrical section, so although its suggested to be built over the plan, the t. will need some support if you do this. Liteply means pins need a bit of effort to push down and secure to the building board so, discarding the plan, I drew a large right-angle on my workbench representing the wing outline corners and squared the structure up to this while also supporting the t. The parts fit well, but some ribs and the t. should be weighed or taped down to prevent twists. Okay, heres a few items of note for this part of the construction:

O Leading edge part W8 needs a

little trimming to fit.

O Note that the ailerons must be

trimmed to fit, too.

O The manuals reference to a central aileron servo can be ignored as the model is designed to accept a servo in each wing.

ΤΑΙL ΕΝΙΟ The depth of the balsa from which the tail parts are cut surprised me. Thank goodness for all those lightening holesMind you, the parts come down nicely using the sanding

of parts – one each for the wing and fuselage.

The fuselage is a neat and very useful inclusion.

25

Wheel clearance is good and the spats robust. If youve complained about an ARTFUC in the past then don't ignore this opportunity!

A few personal touches include my own pilot figure and a spinner thats better suited to an

| Laser-cut trado kit

block. Here, then, note the following points of interest.

O If youre a firsttime builder don't

forget to round the tailplane I., despite the square edge depicted on the plan.

O All control surfaces are predrilled to accept the control horns, which is a nice touch.

FUSELAGE Like the wing, the fuselage is a lasercut, slottogether, thin liteply structure. The manual has got a bit bored by now and popped out for a coffee, so youre largely on your own. Its made by assembling the sides, adding the formers to one such, then adding the other side and bringing the tail ends together after inserting a jig. This jig, a rectangular aluminium rod, is included with the kit yet its purpose isnt stated other than with a reference to insert it. Builders will see that some formers have a rectangular slot cut in them, through which it passes, and the purpose is obvious as it draws the sides together, straight and true. Its a clever method and demonstrates how Seagulls people can build models quickly and accurately. Here, then:

O The manual omits to mention that

the rear formers shouldn't be fixed until F16 and F17 – the upper and lower strips – have been added.

F14 and F15 arent mentioned in the manual or plan but should be used to add strength where the fuselage halves join. They also provide guidance slots for . Again, ignored by the manual and not noted on the plan, F26 sits on F27 inside the fuselage so as to improve purchase for the tail wheel mounting screws. If youve complained about ARTF uc rigidity then heres an opportunity to do something about it. I wouldn't describe this area as structurally unsound, but wouldn't blame those who beef things up a bit. I did. Although side- and down-thrust are noted on the plan the parts dont seem to align accordingly without some interference from the builder. As a result its all too easy to set everything perfectly square. The appropriate adjustment could be made using

washers when fitting the engine or

motor mounts, though. Seagulls suggestion that the ESC is laid over the battery is entirely

impractical, so those using electric

power may decide to place it under the battery tray and drill air cooling holes in the lower face of

. This is best done before the part is fitted. O Of course, the tray for elevator

and rudder servos can be adjusted before fitting so as to accept your servo choices. O Pushrod guide tubes must cross

over mid-fuselage en route to the tail feathers. o The upper parts of F2 – are

scored and designed to be easily cut away to provide hatch access after the jig has been removed. O If its not obvious, part F31 is the canopy hatch floor, while F25 provides the fuselage base upon which it sits. o The hatch rear, part 35, is best

added with the hatch in situ so as to get alignment correct. A layer of cling film prevents the hatch from sticking down in error. o The manual omits the hatch top sheeting, however parts F37 are there for that purpose. O Undercarriage assembly is

straightforward, although the axles in my kit had substandard threads so I replaced them with long bolts.

I was generally impressed with the way in which the main assemblies align, although I had trouble getting the wing root to slot into the recess created by the fuselage doubler. It may have been my building accuracy, but I had no option other than to sand the edge of the ply root rib to achieve a good fit.

The tail feathers can be fitted then covered, or covered first. Mind you, the latter seems easier. The manual refers to three lasercut pieces being used to blend the fin to the fuselage and tailplane, but theyre not included. Some tapered balsa is,

words W David Ashby photos y David Ashby / Graham Ashby

though, and must be shaped accordingly. Seagull includes a big sheet of decals that is identical to the ARTF decoration and, in my opinion, not particularly attractive. I imagine few will use them. After all, why would anyone want their efforts mistaken for the ARTF

With the Challenger vaguely reminding me of an RV, I designed my decoration based on a few Google-sourced pics using Oracover and Oratrim. You cant beat polyester film and although Oracover isnt the cheapest covering youll find, it takes loads of heat and can be reheated and easily removed if need be.

Standard servos are what the model was designed for so my Hitec 311s slipped home easily. Powerful miniservos – perhaps Hitec 225BBs – would also be fine. Control surfaces are secured using cyano wick hinges and although the horns may seem overspecified, theres no harm in that. The pushrods use threaded metal clevises and bends, so theyre easy to fit, too.

ΡΟΥΛΙΕR ΟΡΤΙΟΝΙS Both the i. engine mount and the electric motor Standoff mate with F1 using the same bolts and prefitted captive nuts. The outrunners plywood standoff is adjustable so its easy to get a prop adaptor in the right position before fixing the parts (triangular balsa reinforcement is also provided) together using epoxy. The cowl slips over the side cheeks with a squeeze, so I trimmed these back a little. Those fitting an i. engine will find that the manual only describes an upright installation with side cheeks (no cowl) and, to be fair, this does suit the models traditional design. I imagine, though, that many builders will prefer the cowls sleeker lines and sidemount their engine to reduce the amount of material that must be trimmed away. Theres no right or wrong solution here, its really just down to your personal preference.

ELECTRIC AVENUE Twas an outrunner for me, an Overlander 3548/05 900KV unit spinning a 13 6.5" APC prop allied to a 60A ESC, which, hooked up to a LiPo, produces 700W peak at 50A. My ESC lives under the battery tray so | opened slots in the cowl to improve the air cooling and appearance. Incidentally, the covering can be cut away to reveal a lasercut exit aperture in the mid-fuselage underside.

Youll find that theres plenty of room for 3200 – 4000mAh LiPos, and a combination of Velcro strip and straps retain mine safely enough. Flying endurance is a respectable seven minutes, which still leaves around 30% left in the pack.

ΝΕΕΙΟΕΙΟIts worth spending a little time on the cockpit area. Sporting a beret, lets be kind and say that Seagulls pilot figure is bit out of place. I replaced him with an FMS bod left over from a deceased foamy aerobat. A headrest and some instruments followed before the glazing was trimmed and fixed using canopy glue. Thats best achieved in situ, of course, with cling film laid down to stop glue going where it shouldnt.

My model topped the scales at 850z (2.) including battery and the stick-on lead around the motor standoff that was required to get the C of to the suggested point at 60mm back from the I. at the root. Thats in front of the spar, and a very conservative recommendation, so the point can safely come back to the main wing spar without fear.

Seagulls control throws are another safe set of figures, aimed at ensuring nothing dramatic happens during the test flights. Actually, theyre perfect if this model is your followon trainer. Intermediate and experienced pilots will increase aileron and rudder movement soon after the first flight, although the suggested elevator throw is pretty much otherefor a model of this type. Exponential is down to

Its a genuinely attractive model, all the more so if you avoid the supplied decals.

Typically good Seagull hardware is supplied, although some of the horn retention bolts were too short and had to be replaced.

| Laser-cunt trado kit

preference; I use 20% to soften that large elevator while rudder and ailerons seem fine vvithout.

UPWARDS Challenger doesn't offer any surprises in the air. Its a safe, friendly, predictable, fineflying sportster. Slowspeed handling is exemplary at the suggested C of G, with a stall thats very difficult to provoke, especially in stronger winds. My model needed some right aileron trim and a little up elevator, but the side- and downthrust absent as a result of my workbench labours arent too obvious in the air.

Im happy with my power system. It doesn't generate the sort of urge Im familiar with when flying, say, a Foame Acro-Wot, buts whats here is perfect for the sort of model the Challenger is. Manoeuvres come easily with a little planning, while using the models mass also helps, especially when its breezy,

Name:

Model type:

Manufactured by: UK distributor:

RRP:

Wingspan:

Fuselage length:

Wing area:

Allup weight:

Wing loading:

Functions (servos):

Suggested power:

Powertrain fitted:

Ouality:

Assembly:

Flying:

28 ксплав

Challenger Sport aerobat Seagull Models

J. Perkins Distribution www.jperkinsdistribution.co.uk

Easy - Difficult

Improver -

Flying the Challenger has reminded me of my early i. low-wingers, and a good reminder its been. Flying frenetically agile foamies always runs the risk of warping my stick-style so the Challenger has been a reminder to relax. Breathlessdoesn't necessarily mean good

Seagulls throw suggestions deliver a modest roll rate, while rudder deflection must be improved to help with stall turns and spin entry. So doing may provoke some to introduce expoacross these surfaces, but Id suggest going easy with, say, 15% at first. Inverted flight needs only a little forward pressure on elevator and feels safe and solid. Knifeedge flight is better than I was expecting; some coupling is evident, but nothing that cant be managed at the sticks. The Challenger flicks well, too.

Takeoff should be uneventful. Its not a model that should be yanked from the deck, and just needs easing off after a reasonable run. Theres a slight pull to the left when it starts to roll, but nothing a smidgeon of rudder wont correct.

Landing is straightforward, although its easy to let the unyielding, thick dural uc and solid foam tyres bounce the model down the landing strip. This being the case I

Inverted flight feels safe and effortless.

wager that softer tyres will soon be on your shopping list.

FINE CHALLENGE Would I recommend Challenger to firsttime builders? Yes, certainly, although Seagulls first traditional kit isn't without fault. Theyve bundled some items that arent required – decals and pilot – and its obvious that a bit more thought and care should have gone into the production. Theyve got away with it, though, thanks to the simple design where a solution of some sort should come to mind when the plan and instructions dont want to help. Firsttime builders who persevere a little will own an attractive sport aerobat with a personalised scheme that flies very well indeed.

Completion pushes the project cost beyond the ARTFs ticket price, twas ever thus, but would you want a model with such dreary, factoryapplied colours? I cant think of an ARTF that shouts ARTF" more than the Challengers ready-made sibling. Just think of that when you buy covering materials. Besides, building the model has been a relatively quick, absorbing and very enjoyable process, one thats reminded me that I should bash balsa more often.