Foamflyer's RC Airplanes
Getting Started with Electric Flight
How can you get started with electric flight?
There are many kits and plans of electric planes available now. Usually if a company is selling a kit, it is airworthy and performs reasonably well. Keep in mind that "Parkfliers" are slow and gentle flyers, you should not expect vertical performance from them, but they have their own niche. Hobby Lobby has a lot of good planes and accesories, and so does GWS. Pick a plane that matches your piloting capabilities. If you're a beginner, a parkflier may be a good choice, such as a GWS Slow Stick.
See what works well for others
Many people have already had a lot of success and fun with electric planes. Some people like me have given up on glow planes (or slimers as they're referred to). A good way to learn is to ask questions, and the RC Groups Forums is a great place to get lots of information. I started with Speed 400 planes, and these are some of my favorites.
If you're new to flying...
Try to get flight instruction. You can do this at a flying club with varying degrees of success. You might have to join the club, or you may not have to. Also flight simulators can really help increase one's flying skills. Or if you feel up to it you can just learn on your own as I did. Again a parkflier would be a good choice for this.
The major components of electric planes are the airframe, receiver, servos, battery pack, motor, and electronic speed controller (ESC). Everything is pretty much the same as a glow plane, except with electric planes the battery pack is the fuel tank, and the ESC controls the throttle (yes it is fully proportional, not just on and off). The ESC plugs in-between the receiver and the motor, into the THROTTLE port on the receiver (not the BATTERY port). Make sure you have an ESC rated for the amount of amps the motor draws - if it over-amps it will burn out. A 20-amp ESC would be good for a Speed 400 plane, but remember amp draw depends on the propeller you're using. For most parkflyers with smaller highly-geared motors you can get away with a 5 to 10-amp ESC.
Back to Speed 400 planes, what works really well is a 6-volt Speed 400 motor with a 6x3 or 6x4 prop, a 20-amp ESC, and a battery pack consisting of eight cells of at least 1000 mAh each. All this with an airframe AUW (all up weight) of 20 ounces (568 grams) or less. Most of my "So" series of planes use these components, with just two servos (aileron and elevator).
A note about volts and milliamps: Volts is the number of cells in the battery pack. When wired in series, voltage increases as cells are added. Milliamps (or mAh) do not increase, the total for the pack will be the same as for each cell (ensure all cells in the pack are the same). Volts is the RPM or power, milliamps are how long the motor can run. When I use my 8x1100 pack ( 8 cells of 1100 mAh), I fly my single-motor Speed 400 planes with good authority for at least 10 minutes at full throttle.
Make sure you have a good battery pack charger with peak detection that can charge the number of cells in the pack, and make sure you get a good ESC with BEC (Battery Elimination Circuitry). While flying, BEC senses the power left in the pack and cuts off power to the motor when it drops to a preset level, therefore saving power for the radio system. If you didn't have BEC, your plane would have to have a separate 4-cell pack just for the radio. With BEC the same pack runs the motor and radio system. BEC is pretty standard on most ESC's.
There are basically four types of batteries in common use in RC aircraft. First is Nickle-Cadmium (NiCd), pronounced "Nigh-Cad". NiCd cells can generally take a lot of abuse in charging, discharging, and physical (crash).
Next is Nickle Metal-Hydride (NiMH). These cells have much higher capacity (milliamps) compared to NiCd.
Then there's Lithium-Ion (Li-on), which have even greater capacity, but require a different charger than for NiCd or NiMH. These cells were popular several years ago, but are getting harder to find because now Lithium-Polymer has arrived.
Lithium-Polymer (Lipo or Lipolys) are the newset sensation, and have pretty much revolutionized electric flight. Very high capacity compared to NiCds and NiMHs, but again require a special charger. Currently Lipo cells are in their infancy, but can be used to great advantage now in aircraft. You have to be very careful with these cells - If charged with a regular NiCd or NiMH charger they could explode. Also, if charged too fast, even with a lipo charger, they can explode. If you see a "puffed" lipo cell do not use it. Lipos are not recommended for beginners, but as long as you take the proper precautions and treat them with respect they'll be safe. Lipo cells should not be charged at more than 1C (for example, if you have a 1500 mAh pack (1.5 amps), you should not charge it at more than 1.5 amps). Due to this fact, lipos take a little longer to charge compared to NiCds or NiMH, but by cycling several packs you can still fly all the time. Please note that while NiCd and NiMH cells have about 1.2 volts per cell, Lipo cells have 3.7 volts per cell. So a 2-cell lipo is similar to a 6-cell NiCd or NiMH. A 3-cell lipo is nearly the same as a 9 or 10-cell NiCD or NiMH.
There are basically two types of motors, brushed and brushless. Brushed motors have brushes that transfer electric to the commutator in the motor that can wear out, but they're inexpensive ($10 for a Speed 400).
Brushless motors are designed differently than brushed, and since they don't have brushes they have less resistance, therefore they pull fewer amps, and they're much more efficient. They also cost more, about $50 for a small one. Another drawback is that you need a brushless ESC for these motors, which can increase the initial investment in brushless technology. You cannot use a standard brushed ESC with a brushless motor.
Another drawback to brushless is that in multi-motor planes you need an ESC for each motor (correct me if I'm wrong), which again increases cost. With brushed motors you can effectively run multiple motors through one ESC, but make sure the ESC can handle the current.
An imbecile once said,
"If you can't afford to throw $400 in the trash can, you can't afford to fly electric."
This is a tale told by an idiot, signifying nothing.
You can enjoy this hobby on a budget. I've been doing it for years. Like everything, it will consume much of your finances if you let it. The key to preventing this is simple: self discipline, and an appreciation for the simple, yet effective.
Bowling? Golf? Restoring classic cars? Sailing? All these can be expensive if you let them.
If you're a "gotta have it" person, you might be in trouble. You'll buy everything you think you need, then complain that the hobby is expensive. You'll run out and buy a few brushless motors and controllers, a few lipo packs, perhaps some plane kits, then you'll crash them all and believe in the rediculous quote mentioned earlier.
More to come...
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by FoamFlyer