I have some questions I am hoping someone is willing to help me out with as I am quite confused

This is what I want to do: I want to purchase an ARF EasyStar, and I want to use a 4 channel radio for it, the reason being I can use the radio in the future for an upgraded plane, but then I am wondering what servos and receiver i will need for the transmitter, and will the servos and receiver work on the EasyStar? So my questions are as follows:

1. If we are building an ARF plane such as an easystar or a great planes pt, and we supply our own transmitter, reciever servos etc...., my first question is this, Are there specific servos, receiver, and/or ESC's that only work for the type of transmitter we get? Or can we purchase any servos, receiver etc.... for the transmitter? I ask because I may want to purchase a 4 channel transmitter from a friend but he has no servos, receiver or any electronics I would need for the plane so I need to find out exactly what I need to make the radio work.


2. I'm confused on what the difference is between an Electric Speed Contol (ESC) and a servos. How do we know if we need both, or just one, or neither etc...? I always thought esc's are only used on rc cars/trucks but apparently we need them for airplanes to. I thought the throttle on the transmitter controls the speed of the plane and the servos & receiver is what tells the prop how fast it goes. So how does an ESC come into the picture? Why would we need both ESC and Servos? I don't get it.

3. In trying to select a transmitter I can use in the future, by budget is very limited so I cannot invest much into it. But, I have seen many used ones (including what is being sold on this website), and I am wondering what the best brands are. Also, I have seen many 4 channel AM transmitters. they seem to sell much cheaper then the common FM. I realize FM is better, but if I purchase an AM, how will that effect my flight performance? If there is nothing wrong with AM, what is recommended in a 4 or 6 channel system? Are servos and receivers readily available for AM radios? Or, do you recommend me just sticking with FM even though they are more expensive? Is there really that much of a performance difference between the two?

4. What channels does a 27mhz FM transmitter have? Is a 72MHZ better then a 27MHZ FM transmitter? I ask this only if you recommend me staying with the FM frequency

5. Do we need one servo per function on an airplane? So, it goes like this: Prop-1 servo, Rudder- 1 servo, ailerons- 2 servos (1 for each wing)? , and any misc servos for extra functions.....such as xport or combat, or night flight etc... Correct? So then, where does the ESC fit into the picture if we already have a servo for the prop? Do we not need it?

6. On transmitters, if we want to change a channel, do we do this by adding a different crystal to both the transmitter and receiver? Or is there a different way of doing this? Also, are all crystals the same size? Or are there special sizes etc... only for specific transmitters/receivers? What is the exact function of a crystal- is it to set the transmitter/receiver at a specific channel, or does it act as a fuse of some sort also? Does the number on a crystal (example: 2 TX Band) represent the channel it is on?

Well, I think if I can get these questions answered, I'll be able to sleep better at night

Thank you very much for all your help. I realize its a lot of questions, but soon I will know all this

Feel free to PM me as well. Thank you.

1. You could make this more simple by telling us what transmitter your friend has. Then we could tell you to buy a Futaba or Hitec receiver for your Hitec or Futaba radio, or JR, Airtronics or Multiplex receiver for your JR or Airtronics or Multiplex radio. Servos are less restrictive. Just specify what you have.

2. ESC's are used with electric motor powered planes, to control the motor. With a glow engine, you use a servo to control the throttle linkage. Servos move control levers on control surfaces or the engine.

3. FM radios are standard, AM use is sparse. All the available 5 & 6 channel radios are adequate for anything you will be flying in the next couple years. I prefer HiTec. Or Multiplex. Or JR or Futaba.

4. For club flying, select a 72 MHz radio, and any of the channels (they number them, 11 through 60.) If you join a club, check with them first, to see what channels are least used.

5. (See #1)

6. Your transmitter channel must be matched by the receiver. Usually done by using a receiver crystal that matches the transmitter output. Some expensive transmitters can synthesize any of the channels. Crystal swapping is not necessary under most circumstances.

You didn't ask, but I'm going to recommend you visit with an experienced flyer before proceeding. Perhaps your friend who has the transmitter knows about flying and clubs and such. If not, contact a club. Amazing things happen there!

Good luck,
Dave Olson

hi scar,
thank you for your help.
it is a Futaba FP_T6NFK Transmitter 6 channel.
My friend's grandpa owned it so he couldn't answer my questions, and besides, i live in a remote area and I don't know anyone in the hobby persoanlly.

O.k. so, then I assume i will need to get all Futaba servos and receivers, correct? Can I get other brand servos? How about ESC if I want to go with electric? Are the esc/servos combos so i don't have all these seperate componants?

Could you answer question #5 since you know what the transmitter is?

Question #6: are all crystals the same size? Or are there special sizes etc... only for specific transmitters/receivers? What is the exact function of a crystal- is it to set the transmitter/receiver at a specific channel, or does it act as a fuse of some sort also? Does the number on a crystal (example: 2 TX Band) represent the channel it is on?

o.k. thank you again for your help.

You can get a Hitec or Futaba receiver. With the HiTec receiver, you can use HiTec, Jr, Futaba, or the blue-connector Airtronics. Probably others, too, like Cirrus, if you specify the connector. With a Futaba receiver, I know you can use Futaba servos, and GWS. I think that means you can also use JR, HT and blue AirTronics servos, but you must be careful of the orientation of the connector plug in the receiver.

You can get various flightpacks with receiver and 2 or 3 or 4 servos. Two that come to mind are hobbyhorse.com and ServoCity.com. ESC's and electric motors should be purchased (with batteries) from someone knowledgable, at the same time, so that your power system provides the power you need for whatever plane you get. The ESC plugs into the throttle channel in the receiver, just like a servo.

The answer to your question #5.... you need either an ESC or a throttle servo, to control your power. You need servos for each of the other functions you have (elevator, rudder, ailerons) but not necessarily two for ailerons. Many 4 channel planes are set up with one servo for ailerons. Also, some small planes have no rudder, just a fixed vertical stabilizer. Those usually have no landing gear, they just skid in on the belly. When you select a plane, you will see what servos you need... or you can ask about a specific plane before you buy it.

The receiver crystal is not a fuse, it does select the proper frequency. I don't know if they are all the same size. My crystals have the 72MHz "channel" number on them. They are numbered somewhere between 11 and 60, because those are the available "channels" for the places where I fly on 72 MHz. I don't know what "2 tx band" means, unless it refers to a different frequency. I suggest you contact a club or look at the AMA website for more complete information on available frequencies and their designated numbers. AMA is at www.modelaircraft.org.

There are "getting started" sections on lots of places, like RCU, AMA, and the websites of many RCU contributors. It sounds like you could devour a ton of that type information, so let me point you to a couple. Do a search here on RCU for Caffeenman and Geistware, both have sites with introductory material. Their websites are listed on many of their posts.

Best wishes,
Dave Olson

Wow Scar, thanks for all the info. Very thoroughly answered
Yes, I will take your advice and start searching the forums etc... Thanks again for all the help!!!

bookstar,
First, welcome to RCU. Second, slow down and take a deep breath. There's an awful lot to learn before you buy anything.

In my opinion, buying the Futaba 6 NFK isn't worth it, unless you get it for $25 or less, AND it's in excellent condition. I have one, and although it's a decent enough transmitter, I don't think it's worth buying a transmitter with more than 4 channels unless it's a computer radio. (The 6 NFK is not.)

You can buy a brand new Futaba 6 EXA, which IS a computer radio, with 4 servos, the receiver, two new battery packs, a charger (which you'll have to buy separately if the 6 NFK doesn't come with one), plus a switch harness and a servo extension, for about $150. You'll pay that much or more for 4 servos, a receiver with crystal and two battery packs.

But I also wouldn't recemmend buying a radio set up until you figure out what type of plane you're going to want, glow or electric, because if you go with a smaller electric (even if it's relatively sophisticated), you're likely to need mini servos and a mini receiver.

Your best bet would be to go to a local club on a nice weekend afternoon and watch for awhile, then ask questions. There's a good chance that someone will offer to give you a chance with the sticks, and you can often find nice used trainer set-ups for a lot less than buying new. You're also best off finding an instructor to teach you to fly (free at almost every club), because trying to learn on your own usually costs a lot more due to crash damage. []

Go to the AMA's website and use their "Club Locater" page to find clubs in your area. There are many more flying clubs than most newbies realize. http://www.modelair.org/

If there isn't a club near you, I'd highly recommend buying something like an Aerobird Challeger to learn on. The entire set-up, including plane, electric motor, radio equipment, battery packs and charger can be bought for about $150.

Good luck,
Dennis-