Hirobo S.R.B Quark 40MHz Electric Helicopter

Do you know Hirobo S.R.B Quark 40MHz Electric Helicopter?

The S.R.B. Quark offers to those who have mastered hovering with the X.R.B. co-axial counter-rotating indoor electric RC helicopter, an even higher level of freedom of freedom of flight control, while the design ensures greater safety and ease of use.

The S.R.B. Quark employs a single rotor system, yet it has the main rotor and the tail rotor just like general helicopters, providing a more realistic helicopter style. At the same time, its design offers the most superior stability and excellent controllability among the single-rotor RC helicopters.

Although the S.R.B. Quark offers the most superior stability and excellent controllability among the single-rotor RC helicopters, due to the characteristic feature of a single-rotor helicopter, S.R.B Quark’s steering will feel more sensitive than co-axial counter-rotating helicopters like X.R.B, and it requires more stick operation to control take-off or pirouettes. Please read these instructions carefully in order to master the handing of this helicopter.

If you can master the S.R.B. Quark, you will have reached a level where even RC helicopters aimed at experts will be within your ability to control. We hope that this will be your first step into the wonderful world of RC helicopters.

I would recommend this model( Hirobo S.R.B Quark 40MHz Electric Helicopter)to anyone.

It's inherent stability give the pilot the opportunity to recover from various mistakes without necessarily crashing. However, in contrast to counter-rotators, the SRB exhibits single-rotor heli behaviors and flight characteristics, such as the ability to lean in pitch and roll axes and fly at significant speed. It also can fly in light wind.

The pilot has to work to fly the SRB: It CAN be crashed, but it is very forgiving. In my opinion, this is what makes the SRB such an optimal trainer and ideal "next heli" after learning basic piloting with a counter-rotator.

I think the Quark's design is very sensible. It's foam blades absorb crash impact and break, protecting the mechanical components. The included blade balancer is very cleverly designed and works perfectly. All that is required for blade balancing is common household clear tape which blends-away nicely on the foam blade material.

The Quark is quite pricey but, in my opinion, you get what you pay for. I've owned mine for about three or four weeks now and I've truly enjoyed it. All I've had to do is replace broken main rotor blades, and that process is simple and requires only a few minutes. So far, the model has proven to be durable and reliable.

There are some features about the Quark that I think should receive more attention. It has a very quite, brushless motor that provides good power to the main rotors. The tail rotor is driven by its own motor, but the motor is mounted at the opposite end of the tail boom from the tail rotor - inboard near the main rotor shaft. The heli also incorporates a fail-safe system to protect it if it flies too far away from the pilot. The motors shut down and bring the model down. It might crash, but at least you don't loose your expensive model.

As for negatives, there's little I would complain about with the Quark. I'd prefer that it used a 2.4GHz radio system (which Hirobo says they have no plans to produce). I've noticed what I believe to be a little interference during flight, even after using my frequency scanner to be sure my channel is clear. I also wish Hirobo would have produced the Quark with a heading-hold gyro instead of a rate gyro. I have found it impossible to completely eliminate mild left or right piro drift during hover, especially as the battery charge diminishes. Like my previous CX, the gyro adjustment is extremely delicate. On the other hand, during flight, it isn't terribly difficult to control the drift with mild stick inputs once the gyro is well adjusted.

In conclusion, I think the Quark deserves significant acclaim. With it, I am truly enjoying heli flight with minimal down time. For me, it serves as an optimal model for builing my flying skills and developing my sense of flight orientation. Training with my sim is very helpful, but the Quark takes training to the next level, giving me the hands-on experience my sim just can't deliver.

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Choosing the Right Brushless Electric Motor for Your RC Airplane

Today i wnat to teach you ho to choose a Right Brushless Electric Motor for your RC Airplane

Finding the brushless motor that is the best choice for your plane or helicopter can seem to be a daunting task due to the large number that are available. There are a few important considerations you should keep in mind when choosing. This article will help you identify these issues so you can spend more time flying and less time trying to find that “perfect” motor.

Ultimately, you want to swing a certain size prop at a certain RPM. In fact, the freedom you have in choosing propeller size and operating RPM can lead to huge performance gains over comparable glow motors used in many remote control airplanes. Prop and RPM selection determines how much power you need, it is important to choose a motor that is almost at its limits when running at that power level. A motor that is too small will overheat and ruin itself, a motor that is too large will be a detriment to performance, due to the added weight.

Translating propellor size and RPM into power requires some help. This help can come from a computer-based prop simulator. You can also find data posted by someone who has done what you are trying to do; find out what prop they used, what RPM it spun, and how much power was used.

Your list of potential motors should now only contain motors that can comfortably (but not ‘in their sleep’) put out the power you need. Now you’ll have to make decisions on the other things: battery voltage and capacity, direct drive or geared, outrunner or inrunner, and kV.

The easiest choice is whether to use direct drive or a gear box, so make that one first. If you want to turn high RPM (greater than 10,000 RPM) you’ll probably want a direct drive inrunner. For lower RPM, you can run an outrunner in direct drive or an inrunner through a gearbox. The outrunner motor is simpler and quieter, but the inrunner motor in a gearbox can be more adjustable and slightly more efficient. In some cases, the outrunner motor can be quite a bit cheaper. Each has its advantages, so consider them both.

At this point you know what RPM your motor needs to turn. It is either the same as you want the prop to turn(direct drive), or at a ratio faster than the prop when using a gearbox. Motor RPM is going to determine your specific motor and battery choice, by the following approximate formula (assuming lithium polymer batteries).

Motor RPM = 0.8 x 3.5V x Series Cell Count x Motor kV Rating

You need to select the right motor and battery combination that will satisfy the motor RPM formula. You can do it with a low kV motor and a high series cell count battery, or vice versa.

Lithium polymer battery packs are ideal for use with brushless motors in radio controlled airplanes and helicopters due to their low weight and high capacity compared to NiMH and NiCd packs. Along with a brushless motor and battery, you will also need a brushless speed control (ESC) with an amp rating equal to or greater than the peak current drawn by your motor.

Make your choice, order the parts, put them together.You want to make sure that you are near the RPM and power levels you were aiming for. Remember, though, the most important test is how it performs in the air. Fly it, and fine tune with prop selection. Hopefully this article has brought you close enough that a motor or battery change isn’t required.

Hope this information can help u~
in the last month , i brought a AXI Gold Line 4120/18 Outrunner Brushless Motor from rcecho.com.
It is very suitable for my helicopter. And it is powerful~~

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RCECHO Brushless motor

The article How Electric Motors Work explains how brushless motors work. In a typical DC motor, there are permanent magnets on the outside and a spinning armature on the inside. The permanent magnets are stationary, so they are called the stator. The armature rotates, so it is called the rotor.
The armature of a typical DC motor
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The armature contains an electromagnet. When you run electricity into this electromagnet, it creates a magnetic field in the armature that attracts and repels the magnets in the stator. So the armature spins through 180 degrees. To keep it spinning, you have to change the poles of the electromagnet. The brushes handle this change in polarity. They make contact with two spinning electrodes attached to the armature and flip the magnetic polarity of the electromagnet as it spins.
This setup works and is simple and cheap to manufacture, but it has a lot of problems:
The brushes eventually wear out.
Because the brushes are making/breaking connections, you get sparking and electrical noise.
The brushes limit the maximum speed of the motor.
Having the electromagnet in the center of the motor makes it harder to cool.
The use of brushes puts a limit on how many poles the armature can have.
With the advent of cheap computers and power transistors, it became possible to "turn the motor inside out" and eliminate the brushes. In a brushless DC motor (BLDC), you put the permanent magnets on the rotor and you move the electromagnets to the stator. Then you use a computer (connected to high-power transistors) to charge up the electromagnets as the shaft turns. This system has all sorts of advantages:

I have brought a brushless motor from rcecho.com

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