I’ve not long returned after ‘time out’ from this wonderful hobby and I suspect my story will ring true with many. Maybe it was the arrival of children, or maybe your job or something else – whatever the reason, coming back to R/C flying after a lay-off can be fraught with problems. The world moves so fast that the hobby we once knew is now no longer quite as we remember it.
After ten years in the modelling wilderness, I was eventually in a position where I wanted to return, and here lies my first nugget of information: when you decide the time is right to come back, join a club. This may be your old club, but if not, then find one that suits. One of the clubs I visited was just north of Manchester near Tyldesley, Wigan and one of the first models to the flightline was an electric job, not a small, glider-type thing but some form of fun-fly machine. I was ready to start sniggering at the thought of this model staggering around, weighed down by its Sub-C NiCDs. Besides, I thought, what was going on with that transmitter aerial? He wasn’t going to get much range with that little thing, surely?
Holy smoke, he launched it vertically and it kept on going! My jaw hit the floor. But surely this wasn’t going to last very long? When he eventually landed some ten minutes later I was gobsmacked and had some questions to ask.
I found out that the days of NiCDs and brushed motors are long gone and terms like Li-Po, 3s, 2.4 gig and brushless were thrown at me. I clearly needed some help and duly got it from my new clubmates. Lithium Polymer (Li-Po) batteries are now commonplace, even as receiver packs, their weight being incredibly low. I could see that this was all going to take some time to get used to. And those motors, what the heck are all those numbers? Even the code breakers from Bletchley Park would struggle to understand that lot!
I was also informed that there was a new R/C system on the market in the form of 2.4GHz, which did away with crystals, the interminable wait for a peg and an aerial you could catch carp with. I was struggling to take it all in, and then it got worse… Someone turned up with a jet!
There’s no doubt that the changes can be overwhelming for an old hand returning to the hobby. So, where do you start?
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Before you think about spending all your hard-earned cash, take stock of anything stashed away. You may still have some 35MHz gear and whilst 2.4GHz has obvious advantages, there’s no reason to throw away your 35-meg stuff just yet. Truth is, it may be perfectly adequate for your requirements to start with.
If you’re thinking of using your old equipment then you must perform some thorough (range) checks before installing it in an airframe, and check any other ancillary equipment such as switch harnesses, battery packs, extension leads etc. One of our deadly foes is black wire rot. Check to see if you have it by peeling back some insulation on negative leads. If the wire beneath isn’t a shiny copper colour then throw it away. That goes for battery packs as well; even if the voltage looks okay, capacity may well be down to dangerous levels, so unless you have some proper means of checking then it’s best to dispose of the pack. New packs are very cheap nowadays, although don’t look for NiCds as they’re no longer made. Nickel Metal Hydrides (NiMH), particularly of the low loss type, are the ones to look for with Sanyo Eneloops or Vapex Instants being of proven quality.
Those old servos should still be okay, although servo prices have dropped so much in recent years that it may not be worth the worry as a standard servo from a respected manufacturer can be purchased for well under £10.
If you’re in the market for a new radio then 2.4GHz is what you’ll be buying. The frequency delivers a number of significant benefits not least the fact that it’s far less susceptible to noise and interference. Choosing a system can be a problem for there are so many different protocols out there, each with their own acronyms. In my opinion you have one choice and that is to buy a standalone solution. Brands like Futaba, JR, Spektrum, Hitec and Multiplex to name but a few. You’ll be able to use the standalone system with any aircraft you choose, although a new receiver for every aircraft will be required, and it’s here that the cost of additional receivers will have a significant influence on the system you choose. After you’ve made a shortlist of possible radios, go to your model shop and play with the transmitters to see which you prefer. Oh, and when you’ve done that, don’t walk out the store and buy online! Model shops need your support more than ever.
The modular nature of my faithful JR X347 Tx meant that it was possible to upgrade to 2.4GHz simply by swapping out the 35MHz module for a 2.4GHz unit. While this was the cheapest path, I was left with the X347’s Achilles heel: scant few model memories! As a result, it was only a short time before I made my first large investment in the form of a Spektrum DX7 with its 20-model memories. For most flyers, twenty is plenty.
You may have some old loft queens still around that you’d like to resurrect. Again, proper checks need to be made as to their integrity. If a new model is on the shopping list then the choice largely depends on your previous ability and how long you’ve been away from the hobby. Don’t be tempted just to jump straight into the saddle again with the type of aircraft you were flying before. You may well be rustier than you think, so a versatile second airframe like a low-wing trainer, a Wot 4, or even a humble high-wing trainer may be the answer. Actually, the latter is a very good bet and will often be capable of basic aerobatics, especially if you increase the control throws.
No longer can you poke your finger and laugh at Chinese ARTFs, gone are the models made from pallet wood, held together with frog spit or covered in gaudy Blue Peter-style sticky-backed plastic. Nope, today’s offerings are made from laser-cut balsa and ply, many being covered in genuine Oracover (Profilm) and, in quality terms are much better than most modellers could hope to emulate. The choice is huge, too.
Don’t be tempted by that multi-engine scale job. Keep it simple and relatively cheap. Alternatively, if you wish to go back to traditional building, then although some kits survive, they’ll be hard to find in the shops such is the popularity of the ARTF example. Look harder though and you’ll see that many are still available, so ask your model shop owner and see what he can get for you, otherwise you’ll probably have to resort to mail order or show stands.
Glow engines remain a valid choice of power but they’ve been joined by electric and petrol. Electric power has become a perfectly viable alternative to glow, indeed, one that can match and even surpass the performance of our favourite methanol burner. Nevertheless, electric has its problems, one such being the ridiculous numbering systems that manufacturers use to label their products, motors in particular. The best advice here is to make one of two choices: Number one is to go with the set-up suggested by the airframe maker. Here, you’ll enjoy a hassle-free installation and be safe in the knowledge that what you fit will do the job well. The downside, in my experience, is that you can sometimes pay extra for this peace of mind. Number two, then (and this is what I do), is to look at the suggested power package and note down a few things:
- The power output (in watts) using the recommended propeller.
- The recommended propeller.
- Current (in amps) used on that propeller or its maximum constant handling.
- Size and weight of the motor
- Type and size of the Li-Po battery.
This, plus a lot of research on the internet will get you close to the required setup you’ll need. Now that’s fine if you happen to have a recommended setup with which to base choices. Sometimes, however, this isn’t the case, in fact you may even wish to convert an existing airframe (one that was originally intended for i.c.) to electric power. Here some established guidelines can help, notably the ‘watts per pound rule’ – a good guideline for starters.
If you choose a lightweight vintage-style floater, then 50 watts / lb will probably be enough. If equipping an aerobat, then aim for 100 watts / lb. Finally, 200 watts / lb will suit 3D and extreme aerobatic machines. It’s worth seeking out your club’s electric guru, tell him what you’re thinking of buying along with the recommended setup and see what he thinks. Alternatively, make use of RCM&E’s friendly forum here at www.modelflying.co.uk.
On the subject of Li-Pos, the 3s 2p (for example) designation can be a bit baffling. Well, the ‘s’ stands for series and ‘p’ stands for parallel, but here’s how I remember it: 3s is 3 x voltS, and 2p is 2 x caPacity.
A single Li-Po cell has a normal voltage of 3.7 volts, so 3s is 11.1V (3 x 3.7V) and if each of those cells has 2000mAh capacity, then 2p = 2 x 2000 = 4000mAh. Simple eh?
You also have to consider the C rating of the pack, which I remember as being the disCharge rating. Basically multiply the p bit by the C bit, i.e. in our example 4000mAh (the p bit) x 20C. That’s 80,000mAh or 80A, which is the maximum current you can safely pull from the pack, although it’s good practice not to run a power system at 100% continuously so leave a threshold and aim to draw no more than 80% at peak current draw.
CHARGE AND CONNECT
You’ll need to consider a charger if adopting electric power. I bought my IMAX B6 many years ago, a humble 50-watt unit that’ll top-up anything I own. With a max 50 watt output it’s not going to charge large Li-Pos very quickly, but I generally use nothing bigger than 3s so, for me, that’s not really an issue. Larger Li-Pos will demand chargers with a higher power rating (measured in watts). Invest in a watt meter too, as this will remove the guesswork and enable you to measure what your power setup is doing. It’ll prevent you from asking more of the power system components (ESC, motor and battery) than they’re rated for.
Another decision to be made relates to the type of plugs used to connect everything up. With so many on the market it’s essential that your choice provides adequate headroom for the current consumption your setup is likely to pull.
LET IT GLOW
If you prefer the i.c. route then fear not, engines are still around and even better than you remember. ASP and SC have finally got their act together and are now fantastic value for money. Even four-strokes are wonderfully reliable and fine everyday engines.
The old names are still there as well: Irvine, O.S., Enya and Saito are amongst others that have survived the electric onslaught and if you’re fortunate enough to be able to afford one you’ll not be disappointed. Fancy something bigger? Well, petrol engines are more popular than ever before and no longer the converted chainsaw lumps that couldn’t pull the skin off a rice pudding. Powerful, purpose-made petrol engines are available and at a price you’d never have thought possible.
In my opinion there’s never been a better time to return to the hobby. In real terms the costs are lower, the quality higher and the choice more varied. So, what are you waiting for?
Coming back into this hobby can be both a bit scary and exciting at the same time. There’s so much to learn and re-learn, but after a short time you’ll wonder why you didn’t do it sooner. Just relax and enjoy!
Connector types – RCM&E August 2010
Batteries demystified – RCM&E Special Issue 2008
Li-Pos demystified – RCM&E July 2010
Electric Flight demystified – RCM&E April and May 2008
Into the blue (beginners series) – RCM&E Nov 2008 onwards
Radio Daze – Choosing a radio – RCM&E July 2011
Motors demystified – Special Issue 2011
Electric Success – RCM&E Special Issue 2007
Power Planning – RCM&E October 2010 onwards
Choosing a radio – RCM&E July and August 2011
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