Micro coaxial RC helicopters remain to be one of the most amazing and fun products to hit the RC market in years. Yes, they are now being somewhat overshadowed by the quad-rotors in terms of growth potential; but they are still responsible for introducing so many more people to this wonderful hobby in both toy and hobby grade versions.
The cost is low, the fun is high... They work well for just about every age group and ability. They are the perfect introduction for first time flyers to the RC hobby as I've already mentioned on my "RC Helicopters For Beginners & Kids" page; yet experienced RC heli and airplane pilots continue to find them enjoyable for some easy going indoor flying when we just need a bit of a "flying fix" and can't venture outside.
Even though it was discontinued a couple years ago, I still very much enjoy flying my Blade CX3 indoors during the winter months for a little bit of "scale" fun. In the hundreds of flights I have had with it, it continues to work and fly so well.
If you are interested in RC helicopters but are a little intimidated by the complexity and cost of single rotor hobby grade collective pitch helis; Coaxials are the perfect solution. They not only look like conventional helicopters, the hobby grade coaxials all use swashplate cyclic control just like real helicopters. In other words, if your main reason for thinking of getting into the hobby is because of your fascination with helicopters in general, micro coaxials are the obvious choice over micro quad-rotors that look nothing like a conventional helicopter.
Even though coaxials are easy to fly, many of the skills you learn on a hobby grade coaxial RC helicopter are somewhat transferable to single rotor hobby grade RC helis. This holds especially true for understanding the control reversals when practicing nose in hovers .
I had a hard time deciding where I should classify and talk about micro coaxial RC helicopters on my web site.
At first they were going to be included in the Toy RC helicopter section ; but the good hobby grade ones like Blade's Scout CX , mCX , mCX2 , and the CX2 are so much more than simple toys. They have full cyclic control and use on board gyro technology.
The only answer was to create a section devoted just to micro coaxial RC helicopters.
Unlike a conventional single rotor helicopter that only has one main rotor and a tail rotor to counteract the torque produced, coaxial helicopters have two main rotors stacked on top of each other.
Having two rotors also adds rotor mass which produces a significant gyroscopic effect that further stabilizes the helicopter. In short – no other mechanical design is as stable (unless you start throwing 3 axis electronic stabilization systems into the mix). Remember me saying on the home page that all helicopters are unstable? Well, coaxial’s break this rule - unless of course your coaxial heli encounters the infamous Toilet Bowl Effect .
All micro coaxial RC helicopters work the same way. They have two separate electric motors that drive each rotor. You can see this in the picture to the right. Each motor drives a main gear. You can’t see the upper gear that well in this photo because it is hidden by the lower gear.
At any rate, these two main gears turn two main rotor shafts. The outside shaft that powers the lower rotor is hollow and the inner shaft that powers the upper rotor is spinning inside the lower hollow shaft – obviously in the opposite direction – pretty simple.
These two motors control both the lift of the helicopter by speeding up and slowing down. They also control the turning or yaw movement of the heli just like a tail rotor would on a single rotor helicopter. How?
If one rotor is slowed down a bit, and the other is sped up, the one that is turning faster will produce more reactive torque than the slow one and the heli will turn/yaw, just as if a tail rotor turn command was given.
This yaw movement is controlled by a special electronic mixing board that will seamlessly mix the speed of both the motors to allow the required turn rate while also making sure the overall lift remains the same.
Yes, as I already mentioned, hobby grade micro coaxial RC helicopters have a swashplate meaning they have cyclic directional control. There are certainly toy grade micro coaxials that don't have cyclic control and rely on either simple weight distribution or small horizontal tail fans that give them limited forward movement; but I'm focusing on hobby grade coaxials in this write up as it trumps toy grade flight response and precision.
Cyclic gives these helicopters some of the same agility that their more complex single rotor collective pitch big brothers have. The lower rotor has a typical swashplate to produce the cyclic control functions. Hover, fly forwards and backwards, left and right, it is all possible. Throw in some nice controlled pirouettes and you have a very functional and controllable bird.
E-flite/Blade's line of electric micro coaxial helicopters are my top pic for several reasons. They stand out due to value, performance, product support, parts availability, and they all come with DSM2 compatible receivers making them work with any good computerized programmable Spektrum or JR DSM2/X radio if and when you progress in this hobby.
E-flite/Blade calls this wonderful feature Bind-N-Fly (BNF) and is to me, one of the best side results of 2.4 GHz spread spectrum modulation. They all come ready to fly with everything needed to get you air born right away (helicopter, radio, li-po battery, and charger).
The smallest is the Blade mCX , the "m" stands for micro. The mCX was without question, one of the most game changing RC helicopters to have hit the market in the past decade. Everyone raved about it and justifiably so. Never before had this amount of technology (mechanical, aeronautical, and electronic) been applied to anything this small at such a low price.
This little rascal is not much bigger than a Spinmaster Havoc toy helicopter, but outperforms the Havoc in every area. It is easy to fly, very maneuverable, light weight, strong, and of course way too much fun!
Yes it even has a gyro built into its 5 in one electronic control board and uses 2.4GHz spread spectrum RC radio technology. This is the perfect indoor RC helicopter in all respects, and the price is outstanding.
Watch a video of the Blade mCX
To learn more about the Blade mCX, here is my full review on it.
The Blade Scout CX is Blade's answer to the toy helicopter segment. The Scout is my goto gift heli for people who have never flown anything RC before in their lives. This can be from children right up to adults. Hobby grade quality and features at toy heli pricing!
A step up from the tiny Scout CX, mCX, and the mCX2 is the larger and long time favorite Blade CX2 . This coaxial RC helicopter is about twice as big as the Scout CX & mCX/2. It uses a larger 7.4 volt 2 cell 800 mAh Li-Po battery that gives more power and faster flight.
The CX2 is still a great indoor RC helicopter but because it is bigger, you can venture outside on those perfect calm days and really spread your wings.
If you are looking for one of the higher performance coaxial RC helicopters on the market – the Blade CX2 remains to be a solid choice.
This Blade CX2 video manual shows in depth how to set up and fly a coaxial RC helicopter. It will help you understand how they work, how easy they are, and how fun! Click on the picture to the right to place your order.
I have been hearing a fair number of people stating micro coaxial RC helicopters are not going to be around for much longer because of micro quad-rotors. I for one don't agree with that at all. Not because I dislike micro quads, I feel they are also a very good first time helicopter as well; but the one undeniable fact is they look nothing like a conventional helicopter. I personally got into this hobby because I was always fascinated by real helicopters and I know so many other people who continue to get into the hobby for the exact same reason. If you fall into that category yourself and want something simple and fun to fly, a micro coaxial RC heli still is and will remain to be a good RC helicopter to start out on.
On the flip side of the coin; if you really don't care about the true helicopter look or how they work, then I would agree, a micro quad rotor is probably the better route to go. If you want more information about this, again please take a peek at my RC Helicopters For Kids & Beginners page or to find out more about quad-rotors, feel free to take a peek at my quadrocopter page .
To conclude my little coaxial helicopter write-up, I can't resist showing this video of a full size single seat turbine powered coaxial helicopter. I can't think of many "big kids" who would not want this rascal parked in their garage.