What does the 4th channel on a 4 channel add?

[jmr1068204]

I know that I want a coaxial because they are self-stable.

I'm down to trying to figure out if what I am looking for is a 3 channel or 4 channel coaxial, and I want to understand exactly what that 4th channel gives the ability to do. I presume this is the ability to roll left or right? I have read that a 4 channel coaxial is considerably harder to fly than a 3 channel, so I'm a bit puzzled as to why this is so if it is still self-stable with the gyro and dual rotors. How does a 4 channel coaxial roll to the left/right with double rotors like an FP, if the 4th channel does in fact add roll? That's what puzzles me.

I have owned a Honeybee FP and a Blade SR120 in the past. I hated both of them due to their constant need for roll adjustment due to the frequent roll to the left and right. I'm not looking for that kind of heli. Basically what I am trying to get away from is that "roll" that irritated me so much and would frequently cause them to veer off to the left/right and crash down to the ground. I basically want the ability to go up/down, forward/backward, and turn left and right...without having to worry about being on the stick every second to keep it from rolling left or right. But am I correct in thinking that without this presumed left/right ability to roll, diving turns and banked turns would not be possible? This was my issue with the Honeybee FP and SR120. But if that is the case, then a 3 channel would be my best bet. Yet I'm still confused about the difference between a roll on a 4 channel FP heli and a roll on a 4 channel coaxial heli.

In the past, I have also had a little (basically toy) Yiboo/UJ Toys UJ420 3.5 channel 8" heli. It is similar to the Syma S108G 3 channel. It recharged on the computer via a USB cable. Being infrared, it couldn't fly outside. I wished it could have, though. I likewise wished the battery on it wasn't soldered in and could be easily replaced by just plugging another one in.

Working 2 jobs, I don't have time for anything complicated with a high learning curve. I just want something small enough to fly around inside, but that can also have the ability to fly outside on a sunny day with no wind or a very light wind. Something that I can buy parts for if I need to, a battery that can be changed out (to have more than 1). I know that I have some rather picky requirements. I'm also trying to keep it $50 - $100 if possible. I'm not going into the hobby on a serious level, so I'm essentially looking for a cooler version of a toy that will last a while and at least have the ability to change things out on it (motor, battery, parts, etc.).

I will not "outgrow" it or "want more" as I have already dabbled into the FP and single blades, and they just aren't for me. The roll frequency was so irritating to me that I do not have a desire to go back to them again. I want something where I don't have to deal with that. I don't have the time to keep any skills honed on them and I just don't have the patience for it. lol I want something I can basically fly right out of the box and that will be self-stable when hovering, yet that I can fly around doing basic turns and such with.

Size-wise...I'm trying to go for a 12" if I can find one. If it was really stable and I could hover it around and do limited movements inside, even something like a 14" or 16" inch (because I think the larger ones simply look cooler and have more power when flying outside).

[pizzano]

jmr........

Try this place....customer service is hit and miss, but their forum folks can assist you quite well.

http://www.xheli.com/coaxial.html

In the past, I've had pretty good luck with many of the coax 4ch shown at that link.

My preference has always been Exceed or Walkera for 4ch coax's due to the large volume of parts available and interchangable......many are in the price range you prefer.

EDIT: Once you've looked at the spec's on some of the models available, if you still have any questions related to the 4ch coax aspect, chime in.......we've got a few guys here that can help you out with heli details......your fun is about to be elevated!

[xmech2k]

Originally Posted by jmr1068204

I presume this is the ability to roll left or right? I have read that a 4 channel coaxial is considerably harder to fly than a 3 channel, so I'm a bit puzzled as to why this is so if it is still self-stable with the gyro and dual rotors. How does a 4 channel coaxial roll to the left/right with double rotors like an FP, if the 4th channel does in fact add roll? That's what puzzles me.

You are correct, the 4th channel is the 'roll'. Technically, it is left/right cyclic control.

Those 3ch helis us 1ch for the speed of the main rotors, controlling vertical movement. 1ch controls yaw, usually by changing the speed of one or both main rotors to change the heli's direction because of the increase/decrease of torque in the rotors. (Constant heading is maintained when both rotors are the same speed and therefore their torque balances each other.) 3rd channel is then to control forward/reverse movement through the 'tail rotor', a term I use loosely, since you can see it's set to blow up or down, instead of left/right like a regular heli. So unlike a regular heli which uses it's tail rotor to balance the torque of the main rotor, this 3ch tail rotor pushes the tail boom up for fwd flight, or down for reverse flight. 3ch helis generally do not have any cyclic control of either main rotor.

4ch helis use cyclic control on the lower rotor, so you can move fwd/aft, and slide left and right like a regular heli using control of the rotor, not an outside force like the so-called 'tail rotor' of those 3ch heli's. It still controls yaw by varying the speed of the upper vs lower rotor, and of course altitude with rotor speed as well.

I think the 4ch is easier to control, as you can hover tail-in (With the tail facing you) and still move in any direction with the cyclic control. With a 3ch, you have to turn the heli away from any obstacles and then move fwd/aft, so a beginner has to deal with orientation issues right away.

The 4ch heli's are still super stable as the upper rotor uses a flybar to keep the heli still(Just like the 3ch's). It tries to keep the heli in a zero-wind state, so they are not good for outside! You control the lower rotor with the cyclic, but as long as it's trimmed right, if your heli is moving, you just let go of the cyclic, and that upper rotor brings it quickly to a stop. Co-ax heli's are pretty slow, too, because even when you are trying to get it to move fast, the upper rotor is trying to stop it. But that's just fine for beginners.

Personally, I highly recommend the Blade MCX2. I have the old MCX-S300, and MSR. I still enjoy hovering around with the S300.

http://www.horizonhobby.com/browse/p...ers-_-Beginner

Check the link out. They still have the older MCX RTF for just $80, or if you can spring for $120, the MCX RTF is newer (Parts supply won't dry up as fast as the MCX?) and you can adjust the cyclic linkages to get faster flight when you're ready. (Edit: And Horizon Hobby customer service isn't hit and miss!)

Good luck!

[jmr1068204]

[QUOTE=xmech2k;876749]I think the 4ch is easier to control, as you can hover tail-in (With the tail facing you) and still move in any direction with the cyclic control. With a 3ch, you have to turn the heli away from any obstacles and then move fwd/aft, so a beginner has to deal with orientation issues right away.

The 4ch heli's are still super stable as the upper rotor uses a flybar to keep the heli still(Just like the 3ch's). It tries to keep the heli in a zero-wind state, so they are not good for outside! You control the lower rotor with the cyclic, but as long as it's trimmed right, if your heli is moving, you just let go of the cyclic, and that upper rotor brings it quickly to a stop. Co-ax heli's are pretty slow, too, because even when you are trying to get it to move fast, the upper rotor is trying to stop it. But that's just fine for beginners.
QUOTE]


Thanks for the info. I guess I'm still kind of torn between the 3 and 4 channel. Mainly because I had a 3 channel that I had gotten so good with that I was able to breeze around things without an issue. So with the turning the heli away from any obstacles and then moving fwd/aft to get around them...that became simply a diagonal directional control to one side and then back to the other side and I was beyond the obstacle. Do they make any good larger 3 channels? It's mainly just sort of a stress-relieving hobby for me...something to play around with when I'm bored.

[xmech2k]

I'm sure there are decent one's out there, but I really wouldn't know which ones, as I'm not a big fan of them. I like having the cyclic control. I remember seeing one advertised that claimed it could fly in the wind outdoors, but don't remember where or how much it was.

[phillipmorris]

Here is one popular model, no personal experience with this one but size able and sure will handle lighter breezes rather well.

The Big Lama

http://www.hobby-estore.com/ProductD...de=EH-EK-E020A

Note the outside YouTube video at bottom, coaxials known to be solid handling flyers.

[matiac]

Even with nose weight a CX won't fly (forward) in even the slightest breeze...go BACKWARD all day long. I have the Interactive Toys Interceptor 052...little 3 channel rig I got at Toys 'R' Us for 35 bucks, had it for a little over a year of steady, pretty much everyday flying indoors and outdoors, and just the other day had to replace the upper rotors gear...it was cracked, nice thing about the 052 is parts are readily available, SUPER stable, 2 operating frequencies (49.860MHz, 27.145MHz), and a pretty tough little bird. My Son just got the 3.0 version the other day and LOVES it...