Electric question
 

Hey, I wanna get a quick flying electric plane on the field but i'm a little confused and need some help. The plane i wanna get is the YAK 55 ED 3D ARF/ AMM motor combo. I also want to get a li poly 1500 battery. Can I get a regular Futaba micro receiver and servo and will it work if I use those li poly batteries on the receiver or do I get seperate receiver battery? and what about the speed controller? I gotta get a special speed controller? I'm confused.. What do I need to make this work out.

RE: Electric question
 

If the "AMM" motor is a brushless motor, then yes you'll need a special speed control for brushless motors. You should check with the manufacturer too, because not all brushless contgrollers work with all motors.

The critical thing about that LiPoly pack isn't the mAH (1500), it's the voltage (number of cells). LiPolys are typically 3.7 volts per cell (if I remember correctly), so if you're using 2 or more cells you may need something to reduce voltage. Although the ESC may handle that for you.

You might be better off asking this question in one of the RCU electric forums, or over at EZone, which is strictly electrics.

Good luck,
Dennis-

RE: Electric question
 

I'm not familiar with that particular set up. No matter whether it is a brushed motor or brushless motor, you will need an ESC (electronic speed control) between the battery and the rest of the equipment. Brushed and brushless require different types of speed controllers though. In most of these the ESC eliminates the need for a seperate receiver battery as the ESC has an internal regulator that provides the proper voltage (usually 5 volts) to the receiver electronics while it still provides the higher voltage to the motor. The ESC also usually has a voltage cut off built in which will cut the power to the motor when the batteries approach their lower limit yet still provides adequate power to the servos to permit a dead stick landing. It is especially important that the ESC has this feature if you are using LiPo's else you will almost certainly ruin your LiPo's after the first flight or two. The sugestion to check out the electric portions of these forums is a good one. Even better, if your club has any flyers experienced in electric propulsion, check with them before spending any money on any system as many of the lower priced units, IMHO are seriously underpowered and doom you to instant failure.

RE: Electric question
 

Almost all ESCs have a BEC (battery eliminator circuit, aka voltage regulator) to provide about 5V to the RX and servos. The specs for the ESC will tell you if it has a BEC, and it will also give the specs for it by giving a max current or max # of servos it can support...

RE: Electric question
 

I fly electric and just finished building an Eflite Yak 54. I have a park 370 outrunner brushless motor with a park 20 amp esc.
Brushless motors have 3 wires coming out from them. You must use a brushless esc to accept these wires. BTW, brushless is not cheap! The motor and esc for the above is roughly $100. As far as batteries, the lipoly pack plugs into the esc which in turn, the esc plugs into channel # 3 of your rx. No need for battery for rx as the esc handles it. Once the pack gets drained, your motor will shut off however, you will still have power to your servos to land. About lipoly packs. 2 cell packs are 7.4 volts while 3 cell packs are 11.1 volts. You must use a charger designated to charge lipoly cells and must set the correct voltage else, the pack will bulge and could explode and catch on fire. And, you also must watch on the discharge rate of lipoly. If you exceed the amperage given by the pack, it will explode or catch on fire in your plane!!! All depends on how you prop your motor. Bigger prop, bigger amp draw on the pack. Alot of the arfs now will say on the package whats recommended to power the plane. And generally, most planes that are powered by brushless motors will run the 3 cell variety of lipoly packs. Alot of punch there!!!! A 1500 mah 3 cell lipoly pack will run ya around $45 or so...just a ballpark figure. Lastly, use a good 4 channel rx thats small. I run Berg 4 channel micro stamp rx's. Dang things weigh just about nothing plus, most dependable rx you can buy bar none. Berg with xtal will run ya around $55. Good choice for micro servos are hitec 55's. These are about 18 to 20 dollars each.

Dave...