The GMFC Guide to helicopters.

By Dave Perry.

 

Helicopters Part 1

New technology in the model RC helicopter market is fast moving at the moment, and as a result the range of helicopters has never been so great. It is therefore important that those new to the hobby do their research, before starting to part with their cash. Spending a little time early on getting the right equipment now, will save you plenty in the future. Everyone will have a view on what the best and easiest way to start learning to fly is, this guide does not profess to be the answer, it is only one view, and not a club recommendation, but hopefully will point you in the right direction to start your journey off.

The starting point is a little research, there are plenty of heli forums on the web (e.g. rcheliaddict) which will have threads on starting out, with individuals setting out what worked and didn’t work for them. These are a good starting point for a little early reading. Equally join a club (GMFC is open to all), and speak to those that currently fly for their advice and views. Normally most clubs will have a range of fliers, from beginners to veterans (the latter not necessarily equating to experts!). Or look for some professional tuition in your area, and speak to them about what they would recommend.

Once you do delve into the hobby your end goal will probably be to fly ‘collective pitch’ helicopters (more to come on that later). If so don’t expect to pick one up and be able to fly it straight away. Sticking power is needed, and lots of time to practice. Be prepared to crash, you most definitely will. Therefore having access to spares is important, and an inclination towards repairing your own kit. The important thing to remember is that whatever route you choose, keep having fun!

Types of Helicopter

So there are 4 basic types of helicopter.

The Toy Helicopter

These are the £20-£30 micro helicopters (and sometimes larger) that you will generally see being displayed in markets, shopping centres, general toy shops. If you are just dabbling or looking for something for the kids, then these can be fun. They often come with a transmitter and battery, are relatively easy to fly, and can be great fun out of the box. The downside can often be access to spares when you crash or break them, which points you to the next type.

Hobby grade Micro Coaxial Helicopter

When I refer to ‘hobby grade’ I mean those helicopters that are branded and you can purchase from many model shops or online shops (e.g. midland helicopter, fast lads, slough model shop, kings lynn model shop to name but a few). What this means is that individual parts on the helicopter can often be purchased separately for replacements when breakages happen, or additional batteries can be purchased. This way when you have a crash and break the helicopter, a few quid can often get the parts you need to be up and running again, rather than a trip for the whole heli to the bin. This is a good learning point for any size or type of heli – make sure parts are available separately and affordable. Quite often you can also purchase ‘upgrade parts’ for the helicopter from other manufacturers, which can improve the robustness or flight characteristics of the helicopter.

You can purchase these as kits – Ready to Fly (RTF) with all you need in the box to get you going. Or, you can now get as bind-n-fly (BNF), which means you don’t get the transmitter, but you can bind it to your own transmitter if you have a compatible one.

These types of heli have twin contra rotating main blades which counter each other meaning no tail rotor is required. A single main rotor helicopter requires a tail rotor to counteract the torque produced and stop the helicopter from spinning on the spot. These are a great way to start out if you have no experience as they are more stable in flight, are fun, and start introducing real helicopter control – up, down, turn, forward, backward, sideways movement and hovering. They are mainly for flying indoors, but can also be flown outside on a calm day.

A good place to look would be the blade range of helicopters. The Blade MCX2 can be had in both RTF and BNF formats, with the full RTF package being around £70. It also has a bigger brother called the Blade CX4 if you want something a little bigger, but a lot of fun and basic learning in a small environment can be had with the MCX2.

Single Rotor Fixed Pitch Helicopter

The micro single rotor fixed pitch helicopter would be deemed by most to be the next level of helicopter after the coaxial. Whilst these used to come with a small ‘flybar’ to stabilise the helicopter, these are now being replaced by electronic flybarless stabilisation units. They are harder to fly and hover than a coaxial helicopter, requiring pretty much constant input, but they do start to bridge the gap between the coaxial and collective pitch helis. If you have got reasonably good hand eye co-ordination, have done a little flying already, or have some space to learn in, then you may want to consider jumping straight to a micro fixed pitch heli. Equally some argue, that if you have spent some time on the coaxials you can possibly jump straight to a micro collective pitch heli. My personal view is that something like the following heli is brilliant to practice indoors around the house.

The blade MSRX is a great little starter. These are remarkably robust, and will take a little bit of a beating before they break if you are quick to the ‘throttle hold switch’ when crashing. I have bounced mine of walls, doors, furniture, artexed roofs and it still keeps going. These are harder to fly and turn than a coaxial, but will help you progress the basics after hover, especially your orientations and ‘nose in’ flight where controls start to get reversed. This is helped in the MSRX by the flybarless stabilisation system, a 3 axis digital sensor that stabilises the rotor head and also functions as a heading hold gyro (will keep the nose pointing in the direction you leave it at). You can normally pick these up for around £70 RTF, but if you have your own transmitter you can pick these up for £40, which is an absolute bargain for the kit you are getting.

 

Another slightly older but popular (although differing reviews) choice on the forums with a number of beginners has been the Blade 120SR fixed pitch heli. These can still be picked up for between £80-£100, and are slightly larger in size than the MSRX.

 

 

Single Rotor Collective Pitch

Collective pitch helicopters are as difficult as they come. They come in all sizes, small and large, have amazing performance and the full ability to do 3D aerobatic stunt flying, but with that comes increased complexity and cost. At this level you have plenty of options, there are different views on entry point – see part 2 – many good quality manufacturers, and you are likely to start to require more ‘kit’ around you (especially once you go past the micro size of heli).

If you choose a good quality branded collective pitch helicopter then you are unlikely to out-grow it in a few months. You will also be able to upgrade it as your flying becomes more advanced, and of course spares will be readily available for the inevitable crash. More importantly, between the helicopter and your transmitter you should be able to ‘tame down’ a good collective pitch helicopter to learn on. They come in micro size and ‘proper heli’ type/size, and whilst many are now moving to flybarless, you can still get flybarred versions – especially second hand (see part 2). One point I would say at this point is to steer clear of the older single rotor collective pitch helis with fixed pitch electric tail rotors (apart from in the most modern micro helis – example of which below). Certainly in the bigger helis you want a belt driven or shaft driven tail rotor with variable pitch to react fast enough to react to the torque loads from the main rotor (especially when learning).

Basic difference between Fixed Pitch and Collective Pitch in flight

Simplistically to move forward with a fixed pitch heli you push and hold down the forward stick, and to stop you just let go of the stick. With a collective pitch heli you just need to nudge the forward stick and let go, and this will start the heli running forward all things being equal. To stop the heli you then need to put a reverse stick movement in by pulling back on the forward stick to stop forward flight. You are also more likely to have to use some aileron to stop the heli moving left or right.

 

Micro and ‘proper size’ collective pitch helicopters

A general rule of thumb is the bigger the helicopter the more stable it will be in flight and hover if properly set up. Equally the bigger the helicopter the more expensive it will be to repair, and hence the greater the psychological fear factor can be of flying it! Whilst the smaller micro collective pitch helicopters do not generally have the same flight characteristic of flying the bigger ones, they can be a great place to learn and have fun with. More importantly they are cheaper to repair, power, and can be more forgiving in a crash. If you crash a ‘proper’ size heli then you will more than likely be heading to the repair shop, with the micros (being light) as long you hit throttle hold early enough the chances are you will be able to continue flying or a quick field repair could do the job.

So what do I mean by ‘proper heli’. Historically most would have said 450 size of heli and up, but with the advent of the Align 250 (and even 150) this general classification is now more difficult. Whilst a 250 or 150 can be more ‘micro’ in size, the 250 certainly flies more like a large heli than a micro, and is less likely to survive a crash – for this reason at this size if you are learning I would go for one of the micro’s mentioned below. In the ‘larger’ size range of helicopter the Align range mentioned earlier provides a good starting place in the value for money stakes. Good build with mainly metal rather than plastic parts, replacement spares easily available from model shops, and you can buy them in ‘combo’ packs with all you need to build from scratch except the receiver and fuel supply of your choice. Once you have mastered the basics, you can then think about buying some of the higher quality brands of helicopter without breaking the bank on replacement parts!

A lot of flyers have started out on the 450 size of helicopter, and this will take you from hovering to full 3D if you want. It is the largest size of helicopter you can ‘fly’ (read ‘hover/basic manoeuvre’) indoors in a decent size sports hall. That being said it is a helicopter that will cause significant injury if things go wrong, so is more suited to the outdoors. The 450 has been popular as a ‘first helicopter’ as it is big enough to be seen well in outdoor flight, can cope well with some wind (but you will probably want non to light for your initial outings), and is not too large to be intimidating. Cost of parts, batteries, and flight times are also reasonable. If you want to watch the pennies even further, then the Blade 450 is also a popular choice out of the box, but if you can afford it I would push for the align trex. There are many variants but you should be looking at £400-£500 RTF to be up and running new (depending on variant chosen).

 

 

If you are also looking at going the micro size CP route for a bit ‘more fun’ in the early days, then you may want to consider jumping up from the 450 size to the 500 size of helicopter. Whilst this is bigger, it is not that much bigger psychologically than the 450 to fly, but is a lot more stable to learn on. Below is a 450, 500 and 600 size heli for size comparison.

 

After these mid-size helicopters you get into the full size helicopters, 600 size and up. At this point there is a clear psychological impact on learning to fly given their size, and as indicated above they start to become more expensive to run and repair. As an example, a 450 size heli will likely take one 3S lipo battery to run (at say £20-£30 each). A 500 may take one 6S lipo battery at around £50 each. A 600 size and above are likely to be running two 6S batteries, doubling your battery cost to over £100+. In this size of heli you also have the option of going for internal combustion (glow) motors, which we will briefly discuss in part 2.

Below is a picture showing the internal of a Trex 600 pro flybarred helicopter. You can see all the main parts that make up most helicopters. You can see at the bottom on a battery tray which slides in and out two 6cell Lipo batteries (blue), one behind the other. These feed the electronic speed controller which is the green box on the top of the nose. Underneath this on its side with all the wires coming out is the receiver with a satellite receiver half way along the heli towards the bottom. In the middle at the top you can see the round silver motor which drives the main gear (white in the middle of the heli). Clustered around the motor shaft above the main gear are the three servos that control the rotor head, and you can see the fourth tail rotor servo towards the rear of the heli. The black box on the top of the heli just in front of the motor is the gyro.

 

This second photo shows a Trex 500 which is an EFL flybarless version. It has all the same main parts but positioned in slightly different places. This heli takes one 6 cell battery which sits at the front on the nose. As this is flybarless the gyro and receiver of the flybarred version of the 600 above have been replaced on this with a flybarless controller unit which can be seen at the back of the heli above the tail.

 

One of the biggest advances in technology over recent years has been in the micro sized collective pitch heli market, and the ability to fit flybarless stabilisation. Many people are now self-learning through this micro market, or running both a full size and micro in parallel. The fear factor is diminished, and they can be a good choice to introduce your-self to collective pitch. It is possible you could be flying inverted with one of these before you can do circuits on the bigger heli, just down to the psychological factor. Equally they are not the same as flying the bigger heli’s, so you can pick up bad habits as a result!

A great tiny collective pitch heli to have a bit of fun with is the blade nano CPX. Whilst these can be skittish, have awful vibration and tail wag, they are small enough to fly in a hall and will cope remarkably well outdoors. There is a full after sales market of spares and upgrades, and 1 cell batteries are a few pounds. They are fully capable of flying and practising basic 3D inverted flight, and are so light that if flying above longish grass as long as you hit throttle hold you are unlikely to do much serious damage in a crash. By this stage (see part 2) you should have your own transmitter, so a BNF version of this can be had for about £75.

 

A slightly larger version of the nano is the new blade MCPX BL. This is slightly less forgiving than the nano being a little bigger but is one of the new micro collective pitch helis that have small direct drive tail motors that are small enough and light enough to just about keep up with rotor torque of the main blade. Again spare parts and upgrades are a plenty, and 2 cell batteries are less than £10 each. The MCPX BL can be had for about £130 BNF.

 

If you are looking to stay ‘micro-ish’ sized, but get closer to the feel of a larger heli, and still maintain some of the survivability of a micro in a crash, then you should look at the Blade 130X. This is a great little heli and does have a proper shaft driven variable pitch tail rotor. They handle the wind remarkably well, and are a bundle of fun for £130 BNF. Once again 2 cell batteries are cheap with plenty of spare parts and upgrades.

 

To give you an idea of relative size and type, below is a picture of a micro coaxial, msrx, nano, mcpx bl, 130X (Front Row), 450 flybarred, 500 flybarless, and 600 flybarred set of helicopters.

This is just a small selection of the models and makes of helicopter available, and once you get into the 450-500 size upwards, there are a number of good quality manufacturers including Gaui, Mikado Logo, SAB Goblin, Synergy, and Thunder Tiger.

 

Remember, above all else, fly safe, crash safe, and have a lot of fun!
 
 
 
 
 

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