Choosing a Trainer

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Choosing A Trainer


IC or Electric?

When choosing a trainer, one of the first decisions to make is whether to go I/C or electric. This is currently quite a finely-balanced decision and a proportion of it will be down to individual taste. The following list gives a summary of the pros and cons of each (note: a charge rate of 1C is 1 x the pack capacity, so a 1C charge for a 4000 mAh pack will be 4A);


Model Types


IC (Internal Combustion)

Pro Can fly all day on a gallon of fuel. Four-strokes in particular make a nice noise.

Con Lots of support equipment required (starter, fuel pump, glow battery, tools, etc.) Budget (i.e. cheap) engines can sometimes require skill to start & tune. noisy and messy (4 strokes less so).

Electric

Pro No engine hassles - just switch on and go. Quiet and clean.

Con Often limited flight time compared to I/C Flight batteries can take a long time to charge (circa 4 hours for 3 batteries) unless you buy Hyperions G3s or similar that can be charged at 5C; be very, very careful about buying other brands that claim to be OK for charging at 5C - some of them are just old stock re-packaged and won't last long if charged at that rate. LiPos must not be left unattended whilst charging! Requires a specialized charger. It is possible to use a general-purpose charger with a LiPo setting but that's an accident waiting to happen; look at the BVM Jets required reading page, and Chris True's Battery Basics pdf. Usually requires more initial financial investment. Even if LiPos can be discharged to the rated capacity (which is rare, as the label on the outside of the pack often has more to do with marketing hype than reality), discharging them more than 80% will shorten their life, sometimes by a considerable amount. Model shops are often more geared towards selling I/C trainers (West London Models are an exception). Can cause interference on cheap 35 MHz radio gear (2.4 GHz radio is better)

Airframes

Once the decision to go I/C or Electric has been taken, you need to select an airframe. Given the nature of our flying site (windy, with trees at both ends and therefore subject to turbulence), a fairly substantial model will be much easier to fly and will be able to fly in a wider range of weather conditions. In general terms, I wouldn’t recommend a model weighing less than about 4 ½ lb (2 kg), much heavier if possible. In any case, you're not allowed to take your A test (fly without supervision) with a model that weighs less than 1 kg. Also, be aware that some model shops will try and sell you a small, light electric trainer, perhaps because they have rather too many in stock - don't make their problem your problem!

Details

Irvine Tutor 40 Several people in the club have a Tutor 40, it is perhaps a little sluggish on ailerons and needs a fair amount of power - something like an O.S. 46 AX or an Irvine 53. It'll fly on an O.S. 46 LA but there won't be a lot in reserve. Other than this, it is large, heavy, stable, easy to fly and is a very reasonable choice as a first model if you want an ARTF.

Flair Kite Something that might be worth thinking about for those of you who want a traditional kit that is tough, heavy (6 lb +), stable and easy to repair with no discernible bad manners is the Flair Models Kite, normally available from the Sussex Model Centre. These are often the model of choice for commercial training organisations (ATS, Paul Heckles R/C, etc.), and they'll fly in a huge range of conditions when fitted with a 70 four-stroke.

Details

Details

WOT Trainer The WOT Trainer only takes a few hours to put together and (having a tailwheel undercarriage) is slightly better suited to a grass runway. It does seem to fly very well - the stall is benign and it “grooves” very nicely. It weighs about 6 pounds (this is a good thing) but has a large wing to carry the weight and will therefore fly very slowly if required, giving the student plenty of time to think; on the other hand, the controls do seems to be a bit "soft" (not very responsive) the wing loading is very low and if the engine is not capable of a sufficiently slow idle (or if the prop pitch is too high), it can be difficult to land because it won't want to come down, and it isn't really very suited to windy conditions.

RCM-Pelikan Bonnie The RCM-Pelikan Bonnie is available from Puffin Models and is a very nice model to fly, grooves nicely and doesn't seem to have any bad manners. It is aerobatic if the control movements are increased and can be used to take the B test as well. It needs a .32 I/C motor or an Axi 2814/10 brushless motor and 3 LiPo cells. On the other hand, it's still small and light so will be affected by wind and turbulence in the same way that many other electric trainers are

Details

Details

Seagull E-Pioneer RCM&E did a review of the E-Pioneer and they seemed to like it. It carries more weight than the average electric trainer (most of which are far too light), but it will still get kicked around badly if the wind gets above about 8-10 mph. Against this, it is very easy to land and the ground handling is good. It requires a 3s 3100 LiPo (although experience suggests that a 3700 is really the minimum size) and a JP EnErG 4220-12 900Kv motor. Moor Models in Watford usually stock them or 4-Max can supply a complete package.

Multiplex Mentor The Mentor is lightly loaded and therefore flies quite slowly, and is quite easy for beginners to cope with in relatively calm conditions. However, it is usually knocked around in turbulence (anything over about 8-10 mph at the patch), and for me, it's also a bit soft on the controls. It requires a 3s Lipo of 3200-4200 mAh capacity, from which you should expect 15-20 minutes of useable flight time with the recommended Himax C3528-1000 brushless outrunner.

Details

In summary, At the moment (late 2011) I think that the state of play with electric trainers is not quite where it needs to be; they're all still too light. If you need to learn to fly in anything other than relatively calm conditions, you're better off getting hold of the a traditional 40 size IC trainer or larger. If you really must fly electric, use the biggest battery pack you can find and accept the fact that sometimes, the wind and turbulence will make the learning process somewhat challenging.