RC Helicopter Tail Rotor Setup 

Rc chinook helicopter not straght go it around

Glad it helped

🙂👍

My pleasure

You bet

You're welcome.

Hi Matthew, assuming you fly with the tail in heading hold, you really don't have to worry too much about creating tail pitch when the servo arm is centered with the pitch arm at a right angle & pitch slider is centered. The gyro will automatically hold in the correct amount of pitch to compensate for the torque to stay locked on heading. Some heli manufacturers setup the tail geometry correctly to be producing a little bit of tail pitch when both the pitch arm and slider are centered, others don't. As you pointed out, the main thing is you set the tail servo travel end limits (in the tail setup section of the Brain programming) correctly so the tail servo is not stalling out when at full left or right pitch.

I plan on updating the swashplate eBook to include the little bit that is different with OpenTX over a conventional computerized radio. It actually isn't really any different, just more options in the swash mix menu to select in OpenTX. OpenTX as you likely know has a swash mix menu just like all conventional computerized radios where you set your type of swash mix (120 or 140 degree) along with the swash mixing percentages and directions for your 3 swashplate directions (pitch, roll, collective). I just did a video recently on the basics of CP heli setup and used the OpenTX radio in the example ( ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-O1L0wxzoqOU.html ). Every single setup step in that video would apply to a flybared heli along with the 120 eCCPM swash leveling e-book I presume you have. The only difference is in the heli setup menu (the swashplate mixing menu) where I say to leave swash type blank in that video, you would select your swashplate mixing type (presumably 120 degree). Leave swash ring setting at 0. OpenTX then gives you the conventional 3 mix values to enter; aileron, elevator, pitch... in that exact order. Unlike conventional radios however, you have to enter the source first for all 3. So for the first one (long cyclic source), you enter elevator input. For lateral cyclic source you enter aileron input, and for collective pitch source, you would enter the channel you have your throttle stick to collective channel output mix. I use channel 10. I can't recall the reasoning behind that CH10. I got it, like all the OpenTX info when I switched from JR to OpenTX from the open TX university website in their helicopter section. Yes, all this info is already available at the OpenTX university site which is the first site I recommend all OpenTX users visit and study. From here on, it's exactly the same then as any other conventional computerized radio. You would start with mix values (the weight value) of around +60%, just like I show in the swash eBook and then adjust the mix percentage up or down to get the amount of cyclic and collective pitch angles you are after. You would reverse any of those weight mix values from + to - if the swash is moving in wrong direction along any of those 3 axis (pitch for the collective direction, aileron for the cyclic roll direction, and elevator for the cyclic pitch direction). Thanks for the comment, hopefully I'll have the swash ebook updated with the OpenTX info soon.

@John Salt: A huge thank you for your reply. I mostly “get it“ . . . from an academic perspective, I would love to see a video with a hands-on OpenTx (teach a man to fish) demonstration. I promise I’ll buy your new book if you walk us through a couple of different fly bar - OpenTx set up scenarios. Can’t thank you enough for your wonderful work.

The 800 :-)

Hope you are keeping your eye on the lipo size, cost, charger, power supply requirements. That's a big factor if you are a newbie or sport flyer who wants to do lots of flying at the park. Keep on. Keep rcheli alive!

Hi Keith, tail gyros can do funny things when a heli is stationary on the bench (in a feedback loop), and can cause the tail servo to hunt as error rates build. It's likely normal but the only way to tell is to get the heli into a solid hover and observe the tail performance for an entire flight. If it also becomes erratic after a few minutes in the air as well, then something could be wrong with either the tail servo or the tail gyro (part of the flight control system).

Thank you sir, I’ll pay close attention next time I fly it.

If the main rotor rotation is CCW, then the reactive torque will be CW meaning the tail has to thrust right instead of left to compensate. As for pitch slider movement direction, it depends on the tail rotor linkage arrangement and which side of the boom the tail rotor is on; but in general, yes, it will pitch in the opposite direction to counter the opposite reactive torque. I always look at tail blade pitch angle to determine thrust vector, not pitch slider direction (because of those possible variations).

@@Rchelicopterfun that's perfect John thanks for that. Luckily I was able to get the Heli light on the skids and it wasn't doing anything nasty so my set-up was correct after all.

As I said in the video, this pitch slider movement direction is the most common to achieve the resultant blade pitch movement, but not always (Blade is backwards of most other brands). It totally depends on which side of the blade grip the control links are attached to. That is what determines which way the blades pitch in relation to slider position.

@@Rchelicopterfun would the gyro comp be backwards as well? I would think that that would be as you explained, (Push tail left, pitch slider goes right)

Yep.

John, Probably a dumb question BUT, is gyro comp turned off if heli is in rate mode? I seem to have messed up something in my open TX software of in the Spirit flb settings as I have NO compensation now. Heli seems to be in rate mode because now rudder goes back to center when I let go of the rudder stick.

Hi Kelly, Not a dumb question at all. My dumb answer however is it shouldn't. In fact, it's even more important to use compensation in rate mode since I-gain is turned off. In the old mechanical gyro days when all we had was rate mode (P-gain only), we still had compensation mixing (called revolution mix back then). I'm not a Spirit user however, so perhaps there is a setting within it that you can disable comp when in rate mode for some reason? Any further technical questions, please contact me through my website as I rarely check for followup questions on YT comments. www.rchelicopterfun.com/

Presuming you mean it's not returning to center when you center the rudder/tail rotor stick on the radio, you are not missing a thing. That is exactly how a tail gyro will function when in Heading Hold mode. Only when a tail gyro is in rate mode will it center when the stick is centered. On this specific heli, I have it setup so I can select between rate mode & heading hold mode so I can I fly both modes. In the the tail servo direction demo I had it in rate mode to better show the pitch slider direction movement. That is why it centered with stick centering. In the following gyro correction direction part of the video, it's switched into heading hold mode so it holds in the left or right movement after I yawed the heli left & right so it would be more visible. If I would have kept it in rate mode during that demo, the pitch slider would have only moved while I was yawing the helicopter and as soon as I stopped, it would have re-centered.

@@Rchelicopterfun Also the gyro moves the wrong direction and will not invert in the outputs menu and the heli just spins in circles. Hate to bug you but I'm a newbe and in my mid 60's and you speak a language I can understand. Do you have a How-to on setting up that Rate/HH switch in OpenTX. I have everything setup in Spektrum AS3X and SAFE.

@RICHARD RHOADS - best to contact me through my website with technical questions like this as I rarely see follow up RU-vid comments. That said, gyro direction setting along with rate/HH mode selection is a function of your specific flybarless system and I can't help much with that. You'll have to reference the instructions that came with your heli/flybarless system or contact Horizon's tech support. I don't know a thing about the flybarless unit the 270 uses, but I'm almost certain it only has HH mode. Only higher end flybarless systems give you the choice of rate mode these days since almost everyone flies with HH now, except for us scale heli guys and gals.

@@Rchelicopterfun Thanks again! I believe I have a defective rec/gyro unit. It is wired up TAER(1234) but rudder won't work on ch4 it only works on ch5 which is Gear and collective only works on ch4. I'm thinking this must be in the FC's programming.

Nope, a properly setup variable pitch tail rotor heli should have fairly equal yaw rates in both directions. One exception would be if you're running very low head speeds and thus the tail rotor will also be spinning slow, so it can barely produce enough thrust to counter the torque of the main rotor. In that case it will yaw much faster in the direction of main rotor torque than it will be able to yaw against main rotor torque.

Nope, size tops out pretty much between 250 & 300 size helicopters.

@@Rchelicopterfun Thanks. I fly the DJI inspire 1 drone, and I am seeking a helicopter configured with a flight-controller to be almost as easy to fly as a drone. So lastly is there a significant difference in novice/beginner-friendliness between the flight-control system JCZK 380A in contrast to the H1.

No idea. Why bother taking up the vastly harder and time intensive hobby of flying collective pitch RC helicopters if you want an easy drone flying experience? Stick with drones so our hobby of RC helicopters is not also ruined and banned everywhere.

@@Rchelicopterfun I have basic skills of flying such helicopters and have extensive practice on simulators of basic flight and hovering, but I still enjoy the carefree ease of a turnkey drone solution. So I seek the ease of a solid helicopter drone platform that has the advantage over a quadcopter of AUTOROTATION, backup in case of power failure. Hence my question of the differences between the 380A vs the H1.

As I said, no idea between the two.

At 5:00 I mention "most, not all"... Starting @ 6:00 I then talk about how to confirm tail thrust by actual blade pitch angle over pitch slider direction.

Right, you mention that, but in a context of the pitch slider. Before that you put a lot of attention to "correct" rotation direction, which may be a bit misleading for beginners having different heli. Maybe some text note over the video around 3:00 would help. Just my five cents though. It is very good video for most of people. Not too many helis there with CW rotating tail. There are probably more, but I know Synergy only.

Thanks for the clarification - sorry I misunderstood. Synergy is the only brand I know of as well with a clockwise spinning tail rotor in the 30+ years I've been into the hobby. I wonder why they do it that way? Thinking not many beginners will be starting out on a higher end Synergy heli, but you are correct that I should at least make mention of it :-)

I've heard that it is not that important really, especially with modern FBL units and for free-style helicopters where tail is rotating fast enough, giving lots of tail authority anyways. Also, 1:1 helis have tail rotating both CW and CCW, on left on right side of the boom . Seems there is no fixed rule there. Truth is though that most of models have CW rotating main rotor, and CCW tail - possibly for a reason... or just everybody is following the pattern ;).

I run the Bavarian Demon 3X flybarless system on this specific heli (Trex 800E).

@@Rchelicopterfun Thank you. Have you ever used V-BAR NEO?

Nope

@@Rchelicopterfun thanks 🙏

Make what at home?

Tail left, tail right. That is what works best (effectively & efficiently) while instructing as students usually get confused with CCW and CW. I only start introducing CCW and CW when we get into day 10 of training - the nose in hover to get them thinking of the heli yawing CCW or CW regardless of orientation.

Good point. In short - follow your specific build instructions and don't listen to some goof on RU-vid 😄

@@Rchelicopterfun don’t take what I said as me calling you a goof lol. Not at all actually I realize many need help and good on you for doing that. I just think model regardless one should be aware that using the full throw available is not always good is all and that you can enter blade stall territory is all. Take care!

@Shawn Scott - I know, I was just trying to be funny. According the wife, I'm king goof, so I just default to that assumption - lol. Regardless of goof factor, thanks again for the max tail pitch reminder for others. 👍

That's exactly why I've built an RC helicopter website over the past decade to help people new to the hobby better understand it: www.rchelicopterfun.com/

That all depends on the specific gyro and your preference/s. For example, some gyros set tail gain on channel 5 output, while others, channel 7 or even whatever channel you assign to it. Some people like a dedicated gain switch or preferer one hooked up to their flight mode toggle so the gain automatically is reduced when switching to higher head RPM. In short follow the manufacturer's instructions on channel setup, assignment and starting gain values; then chose your own preference for switch assignment. Personally, I initially set my tail gain up to a variable output channel so I can tune the gain on the fly. Once I'm happy with the gain output, I will change that channel to a fixed output to set the tail gain at that fixed value/s since it's a set once & forget value for my sport & scale flying style.

@@Rchelicopterfun Thanks for the details 🙏🙏🙏