I'm a newbie to rc flying but did some homework in net trying to understand all the jargons.
I do have some critical questions before I start shelling out money. Could you pls throw in your thoughts?
The following question are relevant only to Electric RC planes
Is there any ARF electric plane currently in market that uses more than 6 channels?
Is PCM radio worth for electric flying for weekend fun. Does PCM radio need expensive or special servos or receiver?
When I buy a radio, should I buy receiver / servo / from the same brand / company?
Will any servo (brand, size, torque) work with any radio / receiver?
Can I use a brushed or brushless motor on any type of lipo battery pack? I'm plannning to buy a lipo that would give me longer fying time ( > 15 minutes). Does high capacity lipo require special motors?
I'm convinced on a 6 channel futuba / JR / Hitec. Your recommendation? I will be flying only electric planes / glider / simple helis in the near future. Should I go for the ones with more channels?
Will any ESC work with any receiver / motor?
I know what BEC is, but Is this a part of the receiver or something else?
What is a synthesizer? Does it mean I can fly my plane at the same time when someone else is also flying?
That depends on how much spare cash you have. I've always used PPM radios, and never had a problem or a gripe.
It needs a PCM receiver. They're more expensive and you'll have less selection in really lightweight receivers with PCM. I notice that many of the modern PCM transmitters will allow you to choose to use PPM -- you'll want to check this on a transmitter-by-transmitter basis, however.
That's not necessary, as long as the receiver is compatible. You need to have the right PCM coding if that's the way you go; if you are transmitting PPM you need to have the right frequency shift. 3rd-party receiver companies will help you select the right one for your brand of transmitter.
Generally, yes.
As long as you don't draw more current than the pack can deliver (LiPo packs have an automatic detection/notification of over current. They use a special indicator called 'smoke and flames').
I don't think you'll need more channels for a long long time. Six channels gets you the four 'main' channels plus flaps and retracts. Unless you go into scale flying, what more do you need?
No. First, brushless motors require a brushless ESC and a brushed motor requires a brushed ESC. Second, you need to get an ESC that can handle the current that the motor is going to want to draw -- you certainly don't want your performance limited by the ESC, or worse your ESC burnt up.
It's usually part of the ESC, but you can get them as separate circuits for applications with lots of motor cells.
You can fly your plane at the same time as someone else as long as your radio is on a different channel from theirs. Radio frequency can either be set with a crystal or with a synthesizer. A crystal is basically installed in the radio (or RF module), so you are locked into that frequency. A synthesized transmitter will let you choose what channel to fly on at the field.
Wow...Thanks Tim, I learnt a lot from your reply that could have taken me hours and hours if I had searched in net.
Just one clarification in item 9 (synthesizer). I'm inclined toward buying a radio with a synthesizer but does it mean I have buy a special receiver or additional equipment in the plane to de-synthesize? If additional equipment is needed then I think it will increase the weight of the electric flyer and may not be worth it? Any thoughts?
Special recievers only - same brand as TX. This is restrictive.
No.
Yes. Essentially. Some plugs are not quite perfect fits, but can be made to be.
No. The only limitations on motor/prop/gearbox, ESC and pack are that everything is operated within current and voltage limits to prevent excessive heat build up in one or other of the components.
Not at this stage. 6 channels is more than enough to start with..but get one with at least some mixing and more than one model memory.
No, Brushless and brushed motors need completely different ESC';s. Apart from that its down to current and voltage ratings when selecting what ESC is needed.
Part of the ESC, or separate sometimes. Separate when using higher voltage packs (>12v) as heat build up in onboard BEC';s gets excessive. Outboard ones use switching technology and are more efficient.
It avoids the irritating (and in the US, technically illegal) practice of having to swap crystals when someone else is on your channel.
In practice, there are a lot of channels to choose from so its no big deal. I would NOT bother with a synthesizer if you are starting up.
There are better things to spend money on
You NEED to join the ezone forums at
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Ask everything you need there. Before buying ANYTHING.
A frequency synthesizer is just a fancy way of generating a carrier wave, where a crystal is a simple way. Once it goes out the antenna there's no difference.
There _are_ manufacturers (Polk is one) making synthesized receivers that figure out where your transmitter is and lock onto it -- but you don't have to use them. Just make sure that your transmitter is on the same channel as your receiver (and put the right frequency flag on) and you'll do fine.
No..a synth is just a way to have all the channels available at the touch of a button.
However you may need either a synthesized receiver to go with it, or a a lot of crystals for your receivers.
Another option would be to get the new DX6 2.5Ghz set..its shorter range, and seems to maybe be a problem in sub zero temps,. but it and the matching receivers find their own frequency slots...so no worries about all this malarkey.
Really I would NOT go mad on expensive transmitters yet.
Maybe a flight simulator is something you could more usefully employ.
If I had to do it all over again what I wold get would be
(i) basic6 channel computer set..somthing like a futaba ff6..I now have two..
(ii) a couple of decent small receivers - Bergs probably
(iii) a box of small servos. I like Hitech HS55, 85 and 85MG ones for small model use.
(iv) an Atsro 109 LIPO charger
(v) a 12 v ex CB regulated power supply for charging at home
(vi) a flower pot for charging LIPOS in In case they go 'poof' - its rare, but when they do you do not want them near anything flammable uncontained.
(vii) a flight simulator. Don't touch a real plane till you can land
100% every time in a controlled fashion on the sim
(ix) a model. What it is depends on your style and reflexes. Kids learn fast on tough crashproof highly manoverable models. They simply lengthen the time between crashes until the thing is under control :-)
Older people prefer more sedate things like slow stiks or vintage style models or electric gliders.
generally what comes with the models (ARTFS) power wise works well enough to start with - don;t go all fancy on kit you may smash completely. Keep it cheap till your crashes become infrequent.
(x) Some LIPOS. What you get depends on what you wil be flying size wise.
(x) Hit the Ezone. I cannot emphasise just how much access to useful information it has been for me. It is simply worth thousands of dollars in wasted money not wasted. And its totally free.
So can I change the crystal if I want to (in the field) ? I assume from your description that I can put any frequency on the receiver in the field?
Now what is the differnce between frequency and channel? If I have a 6 channel radio, I guess this means the radio transmits in 6 different frequencies? Oh Man, Who said rc planes are fun???? Just kidding !!!
I will go to ezonemag for sure before buying anything.
You have simplified my choices for all the components. I will keep this as a reference when placing order.
As for simulator experience, I'm a pro in flying jets (Jane's USAF). I was playing for 3 years now until my Windows 98 crashed due to spyware.
I have my eyes on Su-27 XXL shock flyer as my first plane. I read a lot about starting on a trainer....but...may be its my ego, once I break su-27, may be I'll go for a trainer :)
OK, I will give you my observations...those are different from opinions...opinions can be unfounded or unqualified. There are very few e-models requiring more than 4 channels. I will assume that a fifth might be for landing gear and a sixth for flaps and the like. Four will do most anything you want to do and I have done most of my flying on three...and that is over a 43-year span.
PCM had a real application when xmitters and other sources were splattering signals all over the spectrum. They had some added advantages of having a default position. As if things get out of whack, the motor drops to idle, and the controls go to neutral. Like a lot of things in the hobby, they weren't necessary but just rather nice (fun) to have. I have not had one but many of my OFBs have.
The cheapest way to go will be a complete system. You will have a choice of servo size and that will be about it. I have wanted to buy a few servos and maybe another receiver on occasions but then I found that for $2.29 more, I could get a xmitter and charger. (I exaggerate for emphasis.) Once you have your basic system, servos are so cheap that if you are flying more than one model (and who isn't?) multiple servos are nice because they are the most difficult to switch from model to model, so buying servos as you build new models is a good idea. This will result in you have a lot of servos as you tear up models -- unless you keep building -- as you should. The servos are cheap and there are only a few choices of types. For you basic flying, you will not need digital servos so that limits your choice to two. I believe that one of the major radio brands needs a different direction control pulse. I forget who it is because I have always avoided them for that reason. And I recommend that you do the same. (Some one will immediately post here telling me who this is that is different from all, or at least most, of the others.)
Yes, if you avoid the one non-remembered above.
With any motor and battery pack you will just have to remember what you are expecting of the motor... such as high current loads might disqualify some battery types for use. I have often pulled 60 amps with a motor and that would be a little much for LiPo. For your 15-minute flights, you should have no problems unless you are building large models.
I do not believe that there are any "bad" systems out there...and this includes some real cheapos. At one time, there were several makers one would like to avoid...not so now. I believe that it is Airtronics that have to use different servos from everyone else. I have no problems with Futaba, but I particularly like Hitec. I have several of each. Hitec has always given superb service. You didn't mention computer radios. I will jump in right now on this and catch the flak for it. I recommend that new fliers avoid computer radios. I can explain why when others start saying how crazy I am. I would suggest that you get a Hitec 4-channel system unless you can, right now, think of what you are going to do with those other two channels. Some e-sailplanes might need them for flaps, spoilers, or the like, but that is the only application I can think of. I mod'd one of my 4-channel xmitters to have five channels on a competition Class A, Limited Motor Run sailplane...that is the only one I can think of. Even on some four-channel sailplanes, five-channel xmitters are nice because motor and spoiler controls need to work in a similar manner but not be on the same stick.
Four seems like plenty to me. That is your call. Write down on a piece of paper the functions you would want in these models. Choppers can make great use of a digital radio...but not necessarily. Pattern models can make use of digital radios for some of the coupling that is enjoyed. The coupling of spoilers/flaps to elevator are nice with computer radios, but again, they are not necessary. Again, write down on a piece of paper what functions you might want and decide based on that.
Any receiver, yes. Any motor, no. You obviously need a brushless ESC with a brushless motor.
The BEC is usually built-in to the ESC. I would suggest that you not get a receiver that has these internal to the receiver. The BEC can be disabled for some applications but you will need to know which ESCs you have disabled. The BEC is not a good idea (real neck on the block here) for a high-performance duration model. They are great for any sport plane. In duration flying, there are times that the altitude and range...and the consequent, additional flight time required to continue flying the model at altitude can extend beyond the time left in the motor batteries after the BEC has disconnected the motor function. I have lost models because I kept flying after the BEC cut-out the motor. Consequently, I use 270 mah flight batteries for the receiver. They are small, don't take up much room, easy to replace, and I never worry about ESC or BEC failure, or me extending the flight times well over 45 minutes after the BEC kicked in. They are really nice for non-duration models because when they cut out the motor, that model is going to be on the ground pretty soon.
Yes and no. The current synthesizers are frequency synthesizers and take the place of the crystal. You still would not want the synthesizer in the xmitter on the same frequency as someone else...whether they had a xstal or frequency synthesizer in their xmitter. I am not talking about the new spectrum sweep or spread frequency systems here. I hope this helps. I said many things that others may disagree with but what I said was for the most part true.
Where's the context! Uh oh, it's someone posting from Gooooogle (see the tag line for a link on how to make your google posts look better).
You don't really want to do that. When you change crystals you really need to have the radio tweaked to get the frequency just right. You don't have that problem with synthesizers.
Aaagh!
Two kinds of channel: First type -- channel = frequency. There's a bunch of them, numbered from 10 to, uh, something big. (actually there's also 0-9, but you need an amateur radio license to use one legally). Second type -- channel = number of surfaces you can control. That's the 6 channels in your six channel radio.
So really it's a single-channel six channel radio (if you get a crystal) or a 50 channel six channel radio (if you get the synthesizer).
Clear?
I am _not_ making this up. I am _not_ responsible for this nomenclature!
Just for comparison, if I were starting from scratch:
(i) Futaba 6XAS or Hitec Optic 6 (ie. basic 6ch computer radio) (ii) Ditto the Berg receivers - spend a bit extra on quality receivers - with electric planes, cheap RX's can cause a world of grief. (iii) I like the Waypoint servos - I've used a pile of the 084 units with no problems
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(iv) A charger like the link below - it is badged as Hyperion/Multiplex/Swallow and a few others in different countries. Charges pretty much every battery, easy to use and small.
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(v) A 12v 7.2Ah Gel-Cell and smart charger - they're cheap and quite portable, can be used at home or in the field. (vi) I strongly second the FLIGHT SIM - even the free FMS simulator will put you streets ahead before you take off for real. (vii) If you put in some solid time on the flight sim, you can probably go straight to an intermediate plane - there are heaps out there.
Don't make it too complicated for yourself, after all you're a beginner, buy transmitter/receiver/servo's from the same make. For a decent controller selection you propably have to look at more than one make. Controllers will work with any make, all you need is the proper cable to connect them to your receiver (same cable as on your servo's).
Forget about PCM, but if you wan't to know the pro's and con's:
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Synthesizer is not necessary, stick to one channel. The worse that can happen at a field is that you cannot fly right away when you're ready and you have to wait 15 minutes or so. On the whole, you will not fly less than you plannend. By changing frequencies frequently, you WILL at some time forget your frequency and pick the wrong peg for the frequency board. You WILL crash someone else that way.
Buy brushless motor and brushless controller, longer life, better efficiency, more power. Brushed technology is on the way out the door. Buy LiPo batteries (and LiPo chargers), for the same reason.
Join a club, they will check your plane, will give you flying lessons, do take of and landings for you, until it's safe for you to do it yourself. Otherwise it will probably become an expensive and frustrating hobby.
Especially the FAQ on the homepage:
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FAQ:
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e-flight forum:
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's of e-flight related links and articles:
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Vriendelijke groeten ;-) Ron van Sommeren
14th. int. electric RC fly-in, June 25, Nijmegen, Netherlands see
I think the problem is that we used to use "band" for the frequency assignments, but then we switched to the TV "channel" usage. But in radiodom, "band" meant a range of frequencies. I liked it when someone would ask "what frequency are you on?" My answer was generally, "Twenty-seven oh nine five." Or "Seventy-two sixteen." When we assumed that such technical stuff was too complicated for a modeler to know, then we started screwing up the terminology. At the same time, "channel" became used when we had earlier been using "function." I can remember the desired, magical sound of "simultaneous and proportional." THAT was a major step up, and now it is only relevant with R/C toys of the simpler sort..."This new car has FOUR functions...left, right, forward, and reverse!" By the way, your answer relative to switching xtals was just right for a beginner, as were your other answers.
These are interesting lists but we cannot disregard what we know. And what we know comes from experience and a knowledge base that a beginner does not have. Recommending a computer radio to a fellow who does not understand the difference between channel, function, band, and frequency. Come on now! I hope to heck that when he gets to the field, he is on your frequency! Giving a beginner what we would have started with is good advice, if you can implant in the beginner the knowledge and rational (and experience) that led you to those decisions. I think a beginner should get pretty much what we got as a beginner...but with up-dated technology. Personally, I think a beginner should learn to fly with a single-channel, digital system. He would learn about building, trimming, and the nature of wings that fly and the relationships of speed and atmosphere. But he doesn't want to learn, does he? He just wants to fly. Or they can do what they have always done..."My favorite airplane in the whole wide world is a P-51, so that is going to be my first plane. I figure I will get a bigger engine for it because I will need all that power to get me out of trouble...I can always power back while I am learning. What sort of retracts should I get?" (I wish I was making that up. )
God bless the beginner! I am glad I never was one.
Whatever you do, would you please provide a service here to all the future beginners and to all of we who have taken the time to offer you our advice and observations. If you get a computer radio...please...please...post back here how you like it. If you are having any trouble understanding it and if you are having any difficulty making it do what you want it to do. Please... Return the service.
Don't think for a second your gamer flight sim is going to prepare you for RC flying. It's a whole different ball game! Even a pilots license doesn't give you much advantage, besides a good understanding of flight dynamics. In RC you don't have the view out the window, or a panel full of gauges telling you exactly what's going on, or the seat of the pants feel if you're a RL pilot. The sims specifically for RC (Real Flight, etc.) will give you a HUGE first step in getting your thumbs and brain to function together, with the view and perspective you'll actually experience (or at least close). I've been an avid M/S Flight Sim flyer for 20 years, got my PPL in '67, but only been flying RC for a couple of years (electric, and they're all still flying!), so there is some basis for this opinion....
I'm convinced in buying a basic 6 channel computer radio. No pcm. I'm sure I don't need a 6 channel computer as a beginner but I'm thinking
2-3 years from now. I want to use the same radio for all my planes (Electric only for next 2-3 years).
Another reason I think a computer radio will suit me better is that I'm a systems architect in .net. I work in computers all the time and I guess using computer radio is not in my worry list at all.
Sure I'll post my comments once I buy the radio but it won't apply to a person with little computer skills in the real world.
Thanks
Ken Cashi> On 10 Feb 2006 13:33:51 -0800, snipped-for-privacy@yahoo.com wrote: >
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