Super Power -- AXI Gold Line Double 5330/20 Outrunner

Special power unit based on two AXI 5330 motors was custom designed for aerobatic models of planes up to 16000g. Maximum burst power of this unit reach 6000Watts. DOUBLE AXI 5330/20 GOLD LINE is suitable for use with single propeller but is also ready for two contra rotating props.



Electric motors manufactured by Modelmotors are marked with name and numbers with slash. Name means type of motor (eg.: AXI - brushless 14-pole outrunner, MiniAC - brushless two-pole inrunner). First two numbers mean diameter of stator and next two numbers lenght of stator in mm. Simplified the bigger diameter and lenght the bigger power of motor. The number behind the slash is winding number. The lower winding number the higher RPM and current capacity.

•No. of cells: 10s Li-Poly
•RPM/V: 235 •Max. efficiency: 91%
•Max. efficiency current: 23 - 57A (>85%)
•Current capacity: 75A / 20s
•No load current: 1.8A - 3A
•Internal Resistance: 2 x 45m ohm
•Dimensions (Diameter x Length): 63 x 159mm
•Shaft diameter: 8mm / 32mm
•Weight with cables: 1150g

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Hirobo S.R.B Quark 40MHz Electric Helicopter (Full Set)

The new Hirobo SRB Quark from MRC just arrived at our offices, and naturally, I had to try it out right away. I was so impressed with what I found that we decided to share it with you online immediately so that you won't have to wait for my full review to appear in print. Let's take a look at what makes this machine so special.

FIRST IMPRESSIONS
When I opened the box, I was immediately reminded of the earlier XRB Sky Robo Lama. The Quark shares Hirobo's attention to detail and careful packaging. The main display box has three inner boxes containing the fully assembled helicopter with a brushless motor, the 72MHz FM transmitter and, finally, spare main and tail rotor blades, a balancing charger for the 2S 480mAh LiPo and some basic tools. A great manual rounds out the package.







The Quark has "sacrificial" foam blades similar to those that made the Sky Robo so
safe in the house and around people. These blades are larger and more robust, but they still protect the machine, surrounding objects and people from undue injury if something goes awry. Since it comes fully assembled, though, let's skip right to the good stuff.

IN THE AIR
The Quark features a compact single rotor spanning about 14 inches, and it weighs just 6 ounces ready to fly. Those numbers might indicate a twitchy little handful when flying, but that isn't the case. Owing to the unique flybar system employed, the Quark is exceptionally stable and a perfect step up once you are comfortable with a coaxial ship like the Sky Robo. It is not quite as stable in hover, but unlike with coaxial machines, you can lower its nose and really move out. Before the end of the first battery, I was so comfortable with its stability that I didn't even notice that I had brought my right hand up to catch it until it was in my hand.

After experimenting in the front hall at the office to feel out the hover, I was very impressed when I took this little bird outside to buzz around. It does pitch up a little in forward flight, but not nearly as much as I thought it would. It tracks well, and the tail rotor has plenty of control to help you steer around the yard. Pirouettes stopped immediately, and the tracking while flying backwards is surprisingly clean. It handled the light breezes surprisingly well as I hovered near some of the bushes and then cruised around the parked cars.

Recovery to a hover is smooth, and there's very little tendency to overshoot with the controls. I think that the stability offered by the flybar in hover helps this transition.

THUMBS UP
I am very impressed by the SRB Quark, and I look forward to trying it out in a local school gym. The manual indicates a maximum flight time of 10 minutes, and my initial tests back that up. Yes, it is more expensive than some of the other small helis out there, but this is definitely a case of getting what you pay for, and I expect that the street price will be well below the number shown. The Quark is well made, it includes everything you need, and it flies beautifully. Look for more on this remarkable flyer in my complete report coming soon in Fly RC. That's all for now.

QUICK SPECS
FLYING WEIGHT: 6 oz.
LENGTH: 13.8 in.
ROTOR SPAN: 13.75 in.
ROTOR DISC AREA: 148.5 sq. in.
ROTOR DISC LOADING: 5.8 oz./sq. ft.
RADIO: 4-channel required; flown with included Hirobo SRB transmitter
POWER SYSTEM: Brushless outrunner with 2S 480mAh LiPo battery
DURATION: 9 - 10 min.
MINIMUM FLYING AREA: Any living room or small yard

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Lithium Polymer Battery FAQ(2)

Q3.) How fast can I charge my batteries?

Different cells can withstand different charging rates. Check with the manufacturer to make certain you don't damage your pack.
For fast charging, most packs can be safely charged in 15 minutes, which requires a charging current of 4 times the capacity of the pack.
Trickle charging is usually done at a rate of 1/10th the capacity, or C/10. Cell manufacturers list this as the charge rate in which the cells will not vent (release gases that build up from overcharging). However, even this charge rate can reduce the life expectancy of a cell if left on after the cell is fully charged.

Q4.) What is Cell reversal?
In a battery, not all cells are created equal. One will be weaker than the others. So, as the battery is discharged, the weakest cell will use up all its active material. Now, as discharge continues, the current through the dead cell becomes a charging current, except that it is reversed. So, now reduction is occurring at the positive terminal. As there is no more nickelic hydroxide, it reduces the water, and produces hydrogen. Cell pressure builds, and it vents. The cell has lost water and the life of the cell has been shortened
This is the big danger of battery cycling to prevent memory. Invariably, unless one is very careful, one ends up reversing a cell. It does much more harm than the cycling does good. Also, keep in mind that cells do have a finite life. Each cycle is a bit of life.

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Lithium Polymer Battery FAQ(1)

Q1.) Does Temperature Affect Lithium Polymer Batteries?

Yes, lithium polymer batteries are affected by temperature. All batteries use a chemical reaction to provide electricity, and a low temperature slows this reaction down significantly. You cannot harm a lithium battery by running it at a low temperature, but you will notice a significant decrease in performance. Allowing lithium polymer batteries to freeze is generally not recommended, so be sure to store the lithium battery in a cool, dry location over the winter months.

Q2.) How can I calculate theoretical flight time?

In order to calculate the maximum theoretical flight time of your models, you will need to know some information about your battery and motor equipment:
#Motor Amperage
#Pack capacity in Mah (milliamp hours)

After you have that information, you can use the following formula to compute the maximum theoretical flight time of your model:
Time (hours) = (battery capacity (amps) / (motor current (amps)

Notice how the battery capacity must be given in amps. To find your battery capacity in amps, divide the capacity in milliamps by 1000. You will probably want the result expressed in minutes. so multiply the time you just calculated by 60.

By this formula, a 33.5 amp motor powered by a 5000 Mah battery would have a run time of a run time of 8.96 minutes. This is a theoretical maximum, if you actually ran the above set up for the calculated maximum time you would destroy the battery. Most lipo batteries shouldn’t be discharged below 80%, so multiply the calculated time by .8 to account for this.

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How To Safely Use, Charge, and Discharge Lithium Polymer (Lipo) Batteries

Lithium polymer batteries are great for RC aircraft, but they have an explosive chemistry that must be treated with caution.

Prevent this from happening to your batteries by following these tips:

1. Store lithium polymer batteries in a flame proof LipoSack while charging. - Charging your lithium polymer batteries in a flame proof LipoSack can contain a fire should it occur. It could mean the difference between a minor clean up and the loss of your house or car. Also make sure that the storage area is well ventilated.
   
2. Read the manual – The importance of reading your battery and chargers manual cannot be emphasized enough. The battery manual will state the proper charging rates and times.
   
3. Use common sense – Don’t charge batteries unsupervised. Even when you do everything right, incidents can occur. Also, do not charge lithium polymer batteries in your car. A flame out can be disasterous if it occurs inside a vehicle.
   
4. Use the right battery charger – Charging a lipo battery with a charger designed for other batteries will cause problems, and will probably result in a fire.
   
5. Charge lithium polymer batteries on a fire proof surface – It’s really important to charge lithium polymer batteries on a flame proof surface such as concrete. In the event of a fire, a fire proof charging surface will stop it from spreading, or at least slow it down significantly.
   
6. Keep a fire extinguisher, or bucket of sand near the charging area – If a fire does occur, you don’t want to be running around looking for something to put it out with. Water will not help put out a lipo fire. Being a conductor, it will cause a short circuit and could even make the fire worse.
   
7. Don’t charge lithium polymer batteries near flammable substances – lithium polymer batteries are flammable enough as it is. Don’t make the problem worse by storing flammable substances near charging batteries.
   
8. Check lithium polymer batteries for swelling prior to charging and each use – A puffed battery is unstable, and can be in danger of exploding. If you see a puffed battery, immediately disconnect it from the charger or aircraft and put it in a bucket of water. Dissolve a few tablespoons of salt in the water to aid conductivity, and leave the battery in the bucked for about 4 days. The salt water depletes any power remaining in the battery by creating a short, and it can’t catch fire while underwater. After the four days are up, take the battery out and cut off the connectors (which may come in handy for other projects). You can then dispose of the battery in the trash. The battery no longer contains toxic metals, won’t harm the environment, and by using the salt water you’ve guaranteed that it won’t catch fire. This should be done as soon as you see a puffed battery. You can’t salvage a puffed battery, the best you can do is to dispose of it safely.
   
9. Never charge a lithium polymer battery in a model – If you charge a lipo battery in your RC airplane or helicopter, you are risking the total loss of your model. Only charge lithium polymer batteries on a flame proof surface, in a LipoSack.
   
10. Make sure the charging leads are connected properly – Connecting positive to negative and negative to positive can cause a major fire.
    
11. Don’t overcharge batteries – By their very chemistry, lithium polymer batteries cannot be discharged to a potential of less than 3 volts without damage. For the same reason, don’t charge them to over 4.2 volts. This means that you have to land your rc aircraft before the motors stop turning. Some aircraft come equipped with a voltage cut-off, others do not. If you don’t have a voltage cut-off, then land as soon as you sense the propeller or rotors slowing down.
    
12. Double check that the charger settings are correct – Lithium polymer battery chargers require you to set the battery configuration. Ensure that this configuration matches the battery you’re charging, or else your lipo could get overcharged and explode. Some chargers automatically sense the battery configuration, but make sure that the setting is correct regardless. They have been known to be wrong on occasion.
    
13. Balance lipo batteries – Lithium polymer batteries have balance connectors, designed to make sure that each cell in the pack has the same charge. If this isn’t the case, some cells can become overcharged and explode.
    
14. Never let the battery leads touch – If the battery terminals touch each other, the battery will short circuit and, in most cases, be destroyed. If this happens and you get a puffed battery, dispose of it by following tip 9 above.
    
15. Don’t ever store / charge lithium polymer batteries in your car – Unless you hate your car. Batteries can and do explode, and if this happens inside a vehicle the result is usually catastrophic. On a hot day, temperatures can rise inside the car and cause stored packs to rupture.
    
16. In the event of a crash, remove the battery and supervise it for at least 4 hours – A crashed plane’s battery can appear fine, but can have an internal short circuit. This short circuit can cause an explosion, even hours after the crash occurred. A LipoSack is a great place to keep a battery that’s been in a crash. If enough time elapses and nothing happens, then your battery is probably fine. If you see puffing, dispose of it immediately following the instructions in tip 9 above.

Always use common sense, read the manual, and know the risks associated with lithium polymer batteries. Handled properly, the risk of a fire is relatively small. Store lithium polymer batteries in a LipoSack for additional saftey.

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The difference between Ni-Cd, Ni-MH, and LiPo

As you know ,there are three main types of batteries currently in use for electric airplane motors. These are Nickel Cadmium (NiCad), Nickel Metal Hydride (NiMH) and Lithium Polymer (LiPo).

Dou know the difference between Ni-Cd, Ni-MH, and LiPo this three type of batteries?


Li-polymer Battery
LiPo (Lithium Polymer). This is one of the newest cell types available. It is also the lightest battery type currently available on a commercial basis and can provide more power than the other main cell types. There are no known problems of memory effect with this battery type and it is the easiest battery type to care for. The downside of this battery is that it has the highest engineering costs and therefore the price is usually considerably higher than other cell types.


Ni-MH Battery
Ni-MH (Nickel Metal Hydride). This cell type is the most common cell type currently available for laptop computers, (although Li-ion is rapidly becoming the most popular) This battery type is relatively cheap to manufacture and therefore tends to be cheaper than Li-ion. This cell type is prone to 'memory effect' so it is important to take good care of your Ni-MH battery to ensure that you obtain the best runtimes.


Ni-Cd Battery
Ni-Cd (Nickel Cadmium). This is one of the oldest cell types and is generally only found in older laptops. The main pro for this cell type is its ability to handle higher loads, and therefore is more commonly found in portable power tools or devices that need a lot of power to work efficiently. The main downside of this cell type is that it is notorious for suffering with memory effect so good care must be taken with this battery to ensure most effective use of battery.

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Definetly recommended Motor

RC Smart 893 RPM/V Outrunner Brushless Motor is one great small motor that I have had on gliders and park models.I have had the motor for two years with no problems.Definetly recommended.

RC Smart 893 RPM/V Outrunner Brushless Motor

Specifications

• Rotational Speed: 893 RPM/V
  
  
• Continuous Current: 42A
  
  
• Max. Current: 50A
  
  
• Input Voltage: 8 - 23V
  
  
• Max. Efficiency: 98%
  
  
• No Load Current: 0.9
  
  
• Internal Resistance: 74m ohm
  
  
• Motor Dimensions (Diameter x Length): 37.1mm x 41.1mm
  
  
• Shaft Diameter: 3.93mm (Front and Back)
  
  
• Shaft Length: 12mm (Front) 8.7mm (Back)
  
  
• Input Battery Types: NiCd/ Nimh/ Li-po Battery
  
  
• Recommend Model: Airplane
  

Package Included

• 1 x 893 Outrunner Burshless Motor (with accessories & English Manual)

I brought this motor the internet(http://www.rcmodelland.com/)

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My recommend Battery Charger (2)

In last few day, I recommend two battery chargers to my friend. Today, I will introduce the last one battery charger to you~

G.T.POWER A6 Digital LiPo Li-polymer Balance Charger

The A6 balance charger is a rapid charge / discharger with built in balancer, computerised with micro-oprocessor and specialised operating software.

Specifications

• Operating Voltage Range: DC 10 - 18V
• Circuit Power: Max. 50W for charging, Max. 5W for discharging
• Charge Current Range: 0.1 - 5A
• Discharge Current Range: 0.1 - 1A
• NiCd/NiMH battery cell count: 1 - 15 Cells
• Li-ion/Polymer Cell Count: 1 - 6 Series
• Pb Battery Voltage: 2 - 20V
• Dimensions: 135mm x 100mm x 40mm
• Packet Includes: Multifuctional Connector

Features
Optimized operating software
When charging or discharging, It has an 'AUTO' function that sets the feeding current automatically. Especially for Lithium batteries, it can prevent the over-charging can lead to an explosion by users fault. Every program in the unit is controlled with mutual links and communication for every possible error so it introduces a maximum safety. These can be set at users option.

Special recharge plugsport for receiver, transmitter and igniter charger. And for frequently used charger port such as multi purpose crocodile pin etc.

It provides most convenient balance charge port for Lithium batteries, with separated 3,4,5,6 charge port, and external reverse connector.

High-power and high-performance circuit
It employs the circuit that has maximum output power of 50W. As a result it can charge or discharge up to 15 cells of NiCd/NiMH and 6 series of Lithium batteries with maximum current of 5.0A. Furthermore the cooling system is so efficient that can hold such a power without any trouble of running the CUP or the operating program.

Individual voltage balancer for Lithium batteries inside
It has an individual-cell-voltage balancer inside. This does not require any extra balancer separately when charging Lithium batteries (Lilo/LiPO/LiFe) for cell voltage balancing.

Balance individual cells on discharge
It also can monitor and balance individual cells of the Lithium battery pack during the discharge process. If the voltage of any one cell varies abnormally, the process will be stopped with the error message.

Accept various types of Lithium battery
It can accept three types of Lithium batteries - Lilo, LiPo and LiFe. They have different characteristics by their chemistry. You can select any one of them that you are going to process before the job. For their specifications, refer 'Warnings and safety notes' section.

Lithium battery 'Fast' and 'Storage' mode
You can charge Lithium battery for special purposes. 'Fast' charge reduces the charging time of Lithium battery and 'storage' mode controls the final voltage of the battery to be suit for long time storage.

Maximum safety
Delta-peak sensitivity: The automatic charge termination program works on the principle of the Delta-peak voltage detection. (NiCd/NiMH)

Auto-charge current limit: When charging NiCd or NiMH at 'AUTO' current mode, you can set the upper limit of change current to avoid from high current charging. This is very useful when charging the low impedance and small capacity NiMH battery in 'AUTO' mode.

Capacity limit: The changing capacity always calculated by multiple of the charging current and time. If the charging capacity exceeds the limit the process will be terminated automatically when you set the maximum value.

Processing time limit: you can also restrain the maximum process time to prevent form any possible defect.

Input power monitor: To protect the car battery using as input power from being damaged the voltage of it always monitored. If it drops below the lower limit the process will be ended automatically.

Automatic cooling fan: The electric cooling fan comes into action automatically only when the internal temperature of the unit is raised.

Data store / load
For users convenience it can store maximum 5 data of different batteries. You can establish the data contains program setting of the battery to charge or discharge continually. These data can be called out at any time you need and the process can be executed without program setting.

Cyclic charging / discharging
Perform 1 to 5 cycles of charge>discharge or discharge>charge continually for battery refreshing and balancing.

PC based analysis using USB communication
For technical expert, it offers PC based program can analyze the characteristic of the battery by USB port. It shows a graph of voltage, current, capacity and temperature curves. It also shows the individual voltage of each cell in the Lithium battery pack.

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My recommend Battery Charger (1)

In yesterday, I recommend two battery chargers to my friend. Today, I will introduce one of it to you~
iMAX B5 Intelligent Digital Li-polymer Balance Charger

This charger is computerized with a high performance microprocessor and specialized operating software. It can maintain your battery at its best condition and also control them safely. Please read this entire operating manual completely and attentively as it contains a wide of information you need to keep the manual in a safe place and be sure to pass it on to the new owner if you ever dispose of yours imax B5.

Specifications

• Operating Voltage Range: 11 - 18V
• Circuit Power: max. 50W
• Charge Current Range: 0.1 - 5A
• Current drain for balancing Li-po: 200mAh/cell
• NiCd/NiMH battery cell count: 1 - 14 Cells
• Li-ion/Polymer Cell Count: 1 - 5 Cells
• Battery Voltage: 2V, 6V, 12V
• Dimensions: 130mm x 80mm x 23mm
• Packet Includes: Multifuctional Connector
  

Features
Cell Balance and Charger in 1
The iMAX B5 Balance Charger has an individual-cell-voltage balancer built in so it does not need a separate balancer when charging Lipo batteries.

Maximum Safety
The automatic charge termination program works on the principle of the Delta-peak voltage detection.

Capacity Limit
The charging capacity is calculated by multiple of the charging current and time. If the charging capacity exceeds the limit the process will be terminated automatically when you set the maximum value.

Charge Time Limit
You can also set a maximum charge time to prevent any possible over charge.

Input Power Monitor
This function monitors the input voltage from your battery supply and will automatically stop the charge program if your battery falls below the required level.

High Power and High Performance Circuit
The iMax B5 Balance Charger has a maximun output power of 50W. As a result it can charge up to 14 cells of Nicd/NiMh and 5 series of Li-polymer batteries with maximum current of 5A.

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Recommend battery chargers

My friend is planning to buy a Li-polymer Battery balance charger. But he does not know choose which one is better. His intention is to get a reasonably good charger with sufficient function to take good care of the Li-polymer Battery.

He ask me what is my suggestion. I recommend two Battery balance chargers for him to choose.

- iMAX B5 Intelligent Digital Li-polymer Balance Charger

- G.T.POWER A6 Digital LiPo Li-polymer Balance Charger

I will discuss this two Battery balance chargers in next time ~bye

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