Zhuhai RC Flyers Network

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Comment by ZHN Webmaster on 9月 September 15, 2009 at 12:44pm

I'm not sure if they have R/C models, but the model shop next to Dynamics Pizza in Xiangzhou seems to be very well stocked!

Not much flying going on in this typhoon though, right? :)

Comment by John So on 5月 May 1, 2009 at 12:57am

Hi, Orrin, If you try google earth, you will see you have plenty of fields for RC flying around Horizon Cove, some of the road nearby has nearly no traffic which could be used as runways, may be..
Anyway, this hobby is still new for me, I flew a RC plane 15 years ago, and I have a broken RC Chopper from 5 years ago when I only enjoyed for 2 mths. I was thinking of getting a Gas powered trainer to start off again, but may be I will opt for chopper again so that we can share experience and fun.

Comment by Lawrence on 3月 March 23, 2009 at 12:51am

Yea... it is addictive... My nephew got one and I love flying it around the house... I already had to get spare parts from a few crash landings... but you can get these cheap now at the underground...

Comment by Orrin on 3月 March 22, 2009 at 5:55pm

Here is the 6th. and final part...

Control of main rotor torque (yaw control) can be (is) accomplished by the implementation of two major design concepts. The first design configuration incorporates a second “stabilizing” main rotor of equal size and mass, rotating around the same axis as the main rotor, to counteract the torque of the “primary” or “lifting” main rotor. This configuration is called “coaxial”; and although it is almost never used in contemporary full-size helicopters, it is very common in RC helicopter models. The second design configuration (called “single rotor”) adds a long (long enough to provide the required leverage) “tail boom” with a small, variable speed/pitch, vertically-mounted “tail rotor” to supply the required thrust to counteract the torque of the main rotor at the very end of the tail boom. This configuration is used almost exclusively in full-size helicopters; and also on “scale” or high-performance, aerobatic RC helicopter models.

Now, you ask; “This is all very interesting Orrin, but which of these two configurations is best for me?” Well, as with most of life’s questions, the correct answer depends on many factors. As far as RC helicopters are concerned, the primary factor is the amount of (or lack of) RC helicopter flying experience you have. For the beginner, I think that the best choice would be one of many, 4-channel, coaxial rotor designs available in RTF packages from a few reputable manufacturers and vendors via the internet, and from some local shops in Gongbei. At the risk of neglecting to mention several other suitable brands, I suggest that beginners limit their choice of manufacturers to “Esky” and “Walkera”. These two manufacturers have excellent reputations; and they produce some very durable, excellent flying models.

My particular favorite (and the one I am currently flying) is the Esky “Lama V3”.
This is an inexpensive (less than RMB600 for the complete RTF package), reasonably stable and easy to fly (it’s very “honest”, in that it does EXACTLY what YOU command it to do), easy to repair (high-use spare parts such as rotor blades and tail boom assemblies are inexpensive and locally available) after a crash (trust me, you’ll do a LOT of that as your learn to fly), and while it requires 100% concentration to fly, it provides sufficient challenge to keep the pilot interested and prepare for the step up to more complex and capable models.

RC helicopter models (with very few exceptions) with single-rotor configurations and more complex (expensive) electronic and mechanical control mechanisms provide a far broader “performance envelope” (such as the capability to perform precision “3D” aerobatics), are designed and intended for VERY experienced pilots. Therefore, although I will discuss them a bit more in a later section on flying tips and techniques, they are really outside the scope of this discussion.

I have included (hopefully) photos of both coaxial-rotor and single-rotor models. The photo of the coaxial-rotor model is actually a still shot of my Lama V3 flying in the car park at Horizon Cove. The photo of the single-rotor model is actually the base photo I used for this group’s logo. All of the videos I have posted on the “videos” page of this site are of me flying the Lama both inside and outside my apartment. They should give you an idea of this models stability and controllability.

This post is getting a bit too long to hold anybody’s attention, so I’ll end it here with the promise (threat) that I’ll follow up in a few days or so with another post addressing suggested flying tips and techniques for the beginner RC helicopter pilot. As always your comments and suggestions are invited and welcome.

Comment by Orrin on 3月 March 22, 2009 at 5:53pm

Here is part 5...

Historically, one of the most difficult aspects or flight for the fledgling RC helicopter pilot to master has been control of the yaw (nose right/nose left) axis. If, for example, the pilot wanted to make a yaw correction to the left, he would first have to give the “yaw left” command, and when the nose of the model reached the desired new heading, he would then have to give it a “yaw right” command to stop the rotation and hold the heading.

With gyro-stabilization on the yaw axis, however, the pilot merely holds the yaw command until the nose of the model reaches the desired heading and then neutralizes the control. The gyro will sense the movement; and when the command is released, it will literally “snap” the rotation to a stop and hold the model on the new heading until the pilot tells it to do something different. On more advanced (expensive) RC helicopters gyro-stabilization is often applied to other control axis as well. Believe me, this application of gyro-stabilization makes RC helicopter flying much less stressful and far more enjoyable, especially for the novice pilot. Yaw stabilization is found on virtually all high-quality RC helicopters available today; and is certainly something that should be included in a beginner’s first model.

Let’s take a closer look at the models themselves. As I mentioned earlier, within each of the major categories of RC helicopters there are (or can be) several sub-categories. For the training/sport flying category there are two major sub-categories; the “standard”, or “conventional” configuration with a single main rotor and a tail rotor, and the “coaxial” configuration with two contra-rotating main rotors and no tail rotor. Each of these configurations have their own advantages and disadvantages; but to have the helicopter be controllable, the helicopter (either full-size or model) must be of one or the other configuration.

Controllable rotary-wing (helicopter) flight, be it full-scale or RC model, is a matter of balancing a number of physical forces. The only constant of these forces, of course, being gravity. This is also true to a slightly lesser degree with fixed-wing aircraft (airplanes). Perhaps the biggest control problem the pioneers of controllable helicopter had to solve was that of torque from the spinning main rotor and the main rotor’s power source; which is, of course, mechanically linked to the main rotor, and firmly fastened to the helicopter’s frame and/or body. Remember, they key word here is “controllable”.

Certainly, you all remember all this stuff about “torque”, “action/reaction”, “thrust/lift”, and, of course, “leverage”, and “gravity” from your high school physics classes… right? Of course you do! Therefore I don’t have to go very much deeper into these physical forces other than to say that they are indeed real; and need to be dealt with by the helicopter designer. As the main rotor, which is always driven by some power source such as a petrol engine or electric motor, spins through the air to produce lift, it also produces an equal force (torque) that is trying its hardest to spin the body of the helicopter in the opposite direction. Unless countered, this “main rotor torque” reaction will send the helicopter spinning off uncontrollably into the atmosphere. This is not exactly the desired action for controllable flight.

Comment by Orrin on 3月 March 22, 2009 at 5:51pm

Here is part 4...

Which mode is the correct one for you? That’s up to you to decide, and it is relatively easy to switch a transmitter back and forth from one mode to another if you find that your original selection is not comfortable for you. Personally, after 40 years of flying fixed-wing models on Mode 2, I’ve found that I prefer Mode 1 for helicopter flying. The Mode 1 configuration allows me to make frequent yaw inputs without the danger of making an inadvertent change in power setting. Beginner or novice helicopter flyers (like me) will find themselves using the yaw and pitch controls almost exclusively to alter the direction of the model’s flight. Generally speaking, low-time RC helicopter pilots should avoid the bank control until their “RC orientation”, eye/hand coordination, and confidence have become more developed, almost to the point of becoming instinctive.

Now let’s take a look at the model helicopter itself. First of all, let me say this; not all RC helicopters are created equal! Just as with full-size fixed-wing and rotary-wing aircraft, certain RC aircraft are specifically designed for specific tasks, and RC helicopters are no exception. Basically, RC helicopters can be broken down into 3 major categories: 1) training/sport flying, 2) competition scale, and 3) aerobatic/3D (extreme aerobatics). Indeed, within each of these three major categories there are numerous sub-categories; but for the purposes of this discussion I’m going to focus on the major category of training/sport flying.

This particular category of RC helicopters is, without a doubt, the largest and most diverse category in terms of the number and types of RC helicopters contained therein. Here, the prospective RC helicopter pilot will find everything from 2 and 3-channel toys to proper 4-channel, something-resembling-scale model helicopters. Some of the higher quality models even include gyro-assisted stabilization on one or more control axis.

At this point I know that some of you are saying: “Wait a minute! What is all this business about “channels” and “gyro-assisted stabilization” anyway?” The answer to that question is quite simple. A “channel” is a function of the model’s radio system that allows proportional control of one of the model’s four control axis. On the transmitter a channel is represented by one axis of movement (right/left or forward/back) on one or both of the two control sticks.

Inside the helicopter, control inputs from the transmitter are acquired and decoded by the receiver and performed either electronically (such as by varying the speed of one or more of the model’s motors) or mechanically (by moving the “control arms” on one or more electro-mechanical devices called “servos”). Therefore, if your particular model allows control over the thrust (up/down), yaw (nose right/nose left), and pitch (forward/back) axis, you have a 3-channel model. If your model also allows control of the roll (bank right/bank left) axis, you have a 4-channel model.

Sound complicated? You’re right; it is. But wait… there’s more! We have this business of “gyro-stabilization” to discuss. Without getting into a lot of physics, quantum mechanics, and other interesting stuff like that, you’ll have to take my word for it that a gyro (short for “gyroscope”) is a device that, when active, tends to maintain itself in a fixed position in space. Although stabilization gyros have been around the RC world in one form or another for decades, it has only been very recently that they have become small and affordable enough for RC manufacturers to incorporate them into their products.

Comment by Orrin on 3月 March 22, 2009 at 5:49pm

Here is part 3...

Ok, so much for the philosophy. Let’s get into some of the basic technical stuff. All aircraft, be they model or full-size, airplane (fixed-wing) or helicopter (rotary-wing), have multiple “axis of control”. They are: “pitch” (nose up/nose down), “yaw” (nose left/nose right), “roll” (tilt right/left), and “thrust” (power). The pilot’s job is to keep all four axis in some degree of balance to keep the aircraft under control, and to cause it to perform the desired maneuvers. With RC aircraft, the pilot uses a small, hand-held radio transmitter (sometimes called a “controller”) to send his control inputs/commands to the model. All of today’s RC transmitters have two “control sticks”. Which two of the four control axis each stick controls depends on the control “mode” that the manufacturer designated as the default mode. There are two standard control modes; they are:

Mode 1: In this mode the power and roll controls are on the right stick; and the pitch and yaw controls are on the left stick. This is the default mode for Asia and some of Europe.

Mode 2: In this mode the pitch and roll controls are on the right stick, and the power and yaw controls are on the left stick. This is the default mode for North America and some of Europe.

Which mode is the correct one for you? That’s up to you to decide, and it is relatively easy to switch a transmitter back and forth from one mode to another if you find that your original selection is not comfortable for you. Personally, after 40 years of flying fixed-wing models on Mode 2, I’ve found that I prefer Mode 1 for helicopter flying. The Mode 1 configuration allows me to make frequent yaw inputs without the danger of making an inadvertent change in power setting. Beginner or novice helicopter flyers (like me) will find themselves using the yaw and pitch controls almost exclusively to alter the direction of the model’s flight. Generally speaking, low-time RC helicopter pilots should avoid the bank control until their “RC orientation”, eye/hand coordination, and confidence have become more developed, almost to the point of becoming instinctive.

Now let’s take a look at the model helicopter itself. First of all, let me say this; not all RC helicopters are created equal! Just as with full-size fixed-wing and rotary-wing aircraft, certain RC aircraft are specifically designed for specific tasks, and RC helicopters are no exception. Basically, RC helicopters can be broken down into 3 major categories: 1) training/sport flying, 2) competition scale, and 3) aerobatic/3D (extreme aerobatics). Indeed, within each of these three major categories there are numerous sub-categories; but for the purposes of this discussion I’m going to focus on the major category of training/sport flying.

Comment by Orrin on 3月 March 22, 2009 at 5:42pm

Here is part 2...

Before I launch off into a pseudo-tutorial about RC helicopter control, let me preface the whole thing with the following thoughts. The first maneuver the budding RC helicopter pilot learns (or should learn) is hovering; or holding the helicopter absolutely stationary in an imaginary 2-foot cube in space. The hover is the basis of controlled helicopter flight, either model or full-scale; and is the starting point for all other helicopter flight modes/maneuvers. In a full-scale helicopter the pilot uses his hands, feet, eyes and inner ear to maintain a stable hover. With a RC helicopter, however, the pilot has only his eyes and a maximum of four fingers at his disposal to keep the model in a stable hover. Let me put it this way; hovering a RC helicopter is like trying to keep a baseball-size ball bearing perfectly centered on a 2 foot square piece of glass while holding the glass with a maximum of only 4 fingers a full arm’s length in front of you!

With all of the above being said, I contend that RC helicopter flying is the world’s best stress reliever. I say this because the act of successfully flying a RC helicopter requires 110% concentration, thereby leaving absolutely no room in one’s consciousness for any other cares or worries. I believe that less than one hour per week of RC helicopter flying is far more therapeutic and practical than attempting to blot out reality with alcohol or drugs, or spending a few hours on some expensive “head shrinker’s” couch every week.

*WARNING* Guys, Do not, under any circumstances use the excuse of: “I’m sorry honey, but I’m really exhausted after spending 30 minutes maintaining my mental health by flying my toy airplane earlier today.” when you ignore your significant other’s amorous advances or deny her request for you to accompany her to the Gongbei underground market to “help” her shop for another faux leather “Gucci” handbag. Trust me, she won’t buy it!

Comment by Orrin on 3月 March 22, 2009 at 5:39pm

The following is the 1st. of a multi-part comment that is simply too big to enter in one piece...

The following is my attempt at a more-or-less complete thesis on RC helicopter flying. Now, before I go any further, the reader must understand that this is being written by a long-time (ancient) RC modeler with 40+ years’ experience designing, building, and flying fixed-wing RC models. The author’s total flying time on RC helicopters is something in the neighborhood of 3 hours. I hope that puts all of what is to follow into perspective.

RC helicopters did not make a significant appearance on the RC scene until Kavan (a German RC kit manufacturer) introduced a gas engine-powered, 4 channel kit of the Bell “Jet Ranger” in 1974. This was a large (for the time), and absolutely beautiful scale model of the Bell Aircraft Company’s very popular turbine-powered “bird”. Variants of this particular helicopter also saw military service during and after the Vietnam era. Kavan’s kit was a technological marvel and a masterpiece of miniaturized mechanical engineering; but as masterful as it was, it was also very expensive (about 350, 1974 US dollars, not including engine and radio) and a nightmare to build.

The very first production run to hit the US market contained an unfinished molded fiberglass fuselage, several plastic bags full of beautifully CNC-machined parts and pieces, and an assembly manual that was written in German with no English translation. Once built, the model required a very experienced RC pilot to fly it and keep it airworthy. Despite its shortcomings, the “Jet Ranger” became very popular and hundreds of them were built and flown in the US. It also became the genesis from which virtually all of today’s RC helicopters have evolved.

In the past seven or eight years or so, there has been an explosion of affordable, high-quality, electric-powered, ready-to-fly (RTF) RC helicopters on the market. Only ten or twelve years ago, models like these were quite hard to find and in most cases prohibitively expensive for all but the most dedicated, well-heeled modelers. This phenomenon is largely due to the proliferation of very efficient, light weight, and powerful lithium-polymer (LiPo) batteries very similar to those found in today’s mobile phones and notebook computers.

Another contributing factor has been the development and relatively low cost availability of sophisticated on-board electronic speed controllers (ESC), control mixers, pezio-gyro stabilizers, multi-channel mixing transmitters, and virtually interference-proof 2.4 Ghz. radios. I know that to the novice, or those not particularly technically inclined, this must read like a bunch of pure “technobabble”; but I promise to try to sort most of this out for you by the end of this piece.