Flybarless Flight: Getting Used To the Precision

[aaronredbaron]

After about a month of flying the Logo 600 with a flybarless head and Mikado's V-bar (virtual flybar), I am really starting to feel connected with the heli, and have a few flights under my belt with the new 4.0 software. What I have found fascinating is finding out the differences in performance as I switch back and forth between this flybarless heli and all my other flybar equipped machines.

To start off with, the flybarless head is much more efficient than a flybar head. Without the drag of the flybar and the energy it takes to do its job, the rotor head is noticeably different. The head is actually quieter, with less "whishing and whooshing" sounds, if you will. This extra efficiency can be realized either as extra power or longer flight times, and the heli will perform much better at lower headspeeds than without the flybar.

Hover stability is way different with a V-bar machine. It is very odd to get used to at first, because it only responds to your stick commands. It does not need much correction in a hover, and at first it seems overly sensitive. It basically acts like a heading hold gyro, It will hold an attitude, regardless of wind, unless you command a change, so giving small inputs like we normally do in a hover is not necessary. If you try to make constant corrections, it only makes the model chase your inputs.

Forward flight also feels like you have a heading hold gyro. You direct the attitude with the stick, and it follows through. It does not take any input or corrections to maintain a straight line in high speed flight. In fact, you can bog the head pretty severely in high speed flight if your not careful on the collective, and it will not pitch up. It can be very fun to do crazy fast high speed passes, but watch out for your pack temps. You have to be more in tune with your machine because the V-bar will keep the heli flying great even if you push it too hard and bog it enough to damage your batteries.

Aerobatics are where the V-bar truly excels. A flybar equipped heli will pitch up in high speed flight, and this will also appear in high speed aerobatics. If you are doing a forward or backward roll, the heli will want to pitch up and slow down through the maneuver, so gentle nudging is required to help the heli maintain speed. With the V-bar, you point it and it goes. Rolls are axial like a good aerobatic airplane, and when you begin a maneuver like a roll, it keeps the angle you originally dictated, and holds its until you command otherwise. Without the need for constant correction, huge loops come out round and centered without much effort, tail slides are straight and fast, and rolls maintain their course and speed. As you begin to get used to the more pure control feel, you are able to explore faster and more precise aerobatics. Going back and forth between the V-bar and a flybar heli really highlights the differences. You find yourself putting corrections in the V-bar doesn't need, and the flybar begins to feel sloppy and disconnected.

Autos also work very well with the extra efficiency gained by dropping the flybar. The heli will hang at the end as well or better than anything out there, but you have to be careful not to overcontrol. The heli still acts like it has a heading hold gyro on the head, and you only need to add corrections to guide it. A flybar heli may require you to hold some corrections to keep the decent coming in smooth, with the V-bar, you only need to correct the attitude and let the heli do its thing.

Its kind of weird getting used to the feel, but I have never felt so connected to a heli. Any model flying with a properly set up V-bar has the potential to fly like it is on rails. My favorite way to describe it is my new word "simulatoresque" meaning it flies like a simulator.

Edit: It occurred to me the above article reads as if I had flown this Logo with a flybar head. The Logo is available with a flybar head, but the two heads are entirely different. I purchased my Logo as a package from Mikado with the flybarless head and V-bar electronics; it did not include any of the parts to do a flybarred head.

The comparisons between flybarred and flybarless flight in the preceding article are not based on flying the same heli flybarless and without, but more of a general comparison between how my Logo V-bar flies compared to all my other flybar equipped helis.

Anyone else flying flybarless care to chime in?

[aaronredbaron]

pics

[jones007]

I haven't tried it yet, although I suspect it is only a matter of time until flybarless is the norm, much like heading-hold gyros now. That being said, I have a friend that made the switch about 6 months ago, on a Trex 600e, and the learning curve was just brutal. I suspect that the new Mikado software has made it a bit easier, but at that time, the instructions were extremely weak, and he ended up trying to resolve most of his issues via forums, which was definitely hit or miss. It was unfortunate for this guy, as he had only been flying helis for a few months. He was actually pretty good, comfortable in forward flight and loops and rolls, and no problem with nose-in flight, but switching to flybarless set him way back. In retrospect, I would have suggested that he keep one machine flying stock, to keep him flying, and give him a baseline to head towards, and apply the flybarless to a second machine.

Everyone makes the claim that they are much more efficient, and they should be from a parasite drag perspective, but I've never seen anyone back it up with actual flight data. Any chance you could log voltage and current with and without the flybar to actually quantify the savings? Perhaps it's asking a bit much to have you go back to a flybar for the test, but if you have previous data with the same motor and gearing and roughly the same head-speed, it would be interesting to see.

From a controls perspective, I wonder if you lose a bit of efficiency do to increased control latency? While the flaybar is certainly a draggy device, it's control response, say to stabilize the heli when it's hit by a gust, is 1/4 turn of the head, or about 7ms on my 600, and the servos don't do a thing. On the flybarless system, the gyros have to sense the disturbance, the micro controller has to read the gyros, filter, compute a correction, send a command to the servos, and the servos have to respond. Certainly the servos work harder, so we should expect higher current draw in the radio system and decreased lifespan of the servos, but I'm not sure how much impact this will have on the system aerodynamically.

That being said, HH gyros on tail abuse the heck out of tail servos, and we've just gotten used to it. Most likely as the flybarless systems are refined, they will become mainstream, and the HH benefits will out-weigh the costs for most people, and we'll just buy stonger, faster servos for cyclic too.

If you ask me, converting a flybared heli to flybarless is a halfway solution. That's a crazy amount of exposed mainshaft hanging out there with no engineering justification. I think if you are serious about flybarless, you need to go after something like this:

http://www.rcheliresource.com/video-curtis-youngblood-flying-a-90-electric-very-fast/#more-3337

My two cents.

--Kevin

[aaronredbaron]

If you ask me, converting a flybared heli to flybarless is a halfway solution. That's a crazy amount of exposed mainshaft hanging out there with no engineering justification. I think if you are serious about flybarless, you need to go after something like this...

The Logo 600 is a purpose built flybarless helicopter, and the V-bar system was developed in concert with the Mikado helis. I will have to do some digging to find the data to back it up, but I cannot test a flybar head on this heli because I don't have a flybar head for it. :rolleyes: You do use more power in the control, there is no question that is true, but I do believe the overall gains are well worth it. That Henseleit heli you pointed out is bad to the bone, but I don't think all flybarless conversions should be overlooked. With several nice systems on the market to provide stability, and several very nice heads available too, the conversions really aren't difficult and definitely result in impressive machines. One of the beauties of the flybarless systems is the flight performance is replicable on pretty much any machine within reason.

[CSpaced]

Great article, I'm very interested in trying out flybarless myself and this just makes me want to try it even more.

[Sleepyc]

Matt Botos has been rocking these V-bar systems for a while. And let me tell you they can handle ANY aerobatics you can throw at them.
Last week at SEFF Matt did a demo where he was flying a 90 sized machine at like 100 mph in big sweeping inverted loops running the length of the field around 1' off the deck... the system held that rig in place for him like it was on a track system.

I hope to try this system out someday. I love technology!

[ericb]

I would love to try one of these one day.

[aaron07]

I haven't tried it yet, although I suspect it is only a matter of time until flybarless is the norm, much like heading-hold gyros now. That being said, I have a friend that made the switch about 6 months ago, on a Trex 600e, and the learning curve was just brutal. I suspect that the new Mikado software has made it a bit easier, but at that time, the instructions were extremely weak, and he ended up trying to resolve most of his issues via forums, which was definitely hit or miss. It was unfortunate for this guy, as he had only been flying helis for a few months. He was actually pretty good, comfortable in forward flight and loops and rolls, and no problem with nose-in flight, but switching to flybarless set him way back. In retrospect, I would have suggested that he keep one machine flying stock, to keep him flying, and give him a baseline to head towards, and apply the flybarless to a second machine.

Everyone makes the claim that they are much more efficient, and they should be from a parasite drag perspective, but I've never seen anyone back it up with actual flight data. Any chance you could log voltage and current with and without the flybar to actually quantify the savings? Perhaps it's asking a bit much to have you go back to a flybar for the test, but if you have previous data with the same motor and gearing and roughly the same head-speed, it would be interesting to see.

From a controls perspective, I wonder if you lose a bit of efficiency do to increased control latency? While the flaybar is certainly a draggy device, it's control response, say to stabilize the heli when it's hit by a gust, is 1/4 turn of the head, or about 7ms on my 600, and the servos don't do a thing. On the flybarless system, the gyros have to sense the disturbance, the micro controller has to read the gyros, filter, compute a correction, send a command to the servos, and the servos have to respond. Certainly the servos work harder, so we should expect higher current draw in the radio system and decreased lifespan of the servos, but I'm not sure how much impact this will have on the system aerodynamically.

That being said, HH gyros on tail abuse the heck out of tail servos, and we've just gotten used to it. Most likely as the flybarless systems are refined, they will become mainstream, and the HH benefits will out-weigh the costs for most people, and we'll just buy stonger, faster servos for cyclic too.

If you ask me, converting a flybared heli to flybarless is a halfway solution. That's a crazy amount of exposed mainshaft hanging out there with no engineering justification. I think if you are serious about flybarless, you need to go after something like this:

http://www.rcheliresource.com/video-curtis-youngblood-flying-a-90-electric-very-fast/#more-3337

My two cents.

--Kevin

I have LOWERED my flybarless head on my 600. Doesn't seem like a half way solution to me. Heres some things to think about when you put $$ out of the picture.

1.) Lighter
2.) Lower centre of gravity
3.) Less parts count
4.) More efficient
5.) More power on demand
6.) More precision
7.) Flys nicer inverted
8.) Rolls tight
9.) Feels more linear than a flybarred machine
10.) Way less set-up time tuning flybarless machines

[Oilsands]

What is required to change over from a flybar system to one without? Does someone make the parts needed?

[jones007]

Lots of people make the conversion parts now (head and electronics). I think it's still a bit pricey for the electronics, but Align should be releasing their entry in the market soon, and that is sure to drive the market price down.

Aaron, I like that you shortened the mainshaft to get rid of some of the useless length up there, but do you think you're increasing the chance of an in-flight boom-strike? Also, you mention reduced setup time, and I'm assuming this means "mechanical" setup. When you first tried flybarless, how much time did you play around with settings in the electronics before you got it flying well?

I haven't tried flybarless yet, but I've been tempted a few times. However, I had a friend at the local club that converted his Trex 600e, and it didn't work out so well for him. He had only been flying helis for about 4 or 5 months, and was really pretty good, already doing basic aerobatics, loops, rolls, stall-turns, etc, but when he switched to flybarless, he had such a hard time setting up the Mikado system, that his heli really became unflyable for a few months, or at least not comfortable to fly. Unfortunately, the only support he had for tuning the system was forums and some phone calls to the Mikado dealer. He did eventually get the heli flying well, but kind of got burnt out on it at that point, and went back to flying giant-scale plankers. Maybe helis weren't for him anyway, but he definitely went through some major frustrations getting the system flying well. I notice that some of the newer systems are advertising simpler setup, what's your opinion of this? Are the systems at a point now where a novice can jump in and have a reasonable chance of success?

--Kevin

[victorzamora]

Hey guys, I'm looking at upgrading the gyro on my TRex 450. I was between a Spartan and a GY520 and decided on the Futaba strictly for aesthetic reasons (plus I've been wanting one since before I got into heli's) since I've heard the performance is the same. RIGHT before I ordered it, though, I saw a link to a flybarless thread. Now my decision is between a GY520 and a GU-365 or SK360. I was going to modify my current head to flybarless until I can save up some more money for a full FBL head.

I mean, the price difference is minimal...which is what makes the decision so hard.

[OnTheSnap]

IMO, the only decent system available for a 450 is the miniVbar. It's a big advantage to have FBL unit control the tail. Otherwise stick with a Spartan or GY520.

[victorzamora]

Yeah, I just ordered a GY520. Thanks for you input.

[Pellicle]

The costs for flybarless are coming down. Arguably if you start from scratch a new flybarless is equal or less than a flybar helis. Head price is lower since they are simpler, (Outrage flbarless kits are cheaper than the flybarred kits for this reason) no tail gyro is required since it is incorporated in the FSU, not to mention the lower maintenance costs.

I'm obviously an advocate! While you can make a heli fly with many different approaches including without electronics or even a tail gyro I think FSU's allow you to easily tailor the way your heli fly's. If you want the heli to act like it has heavier blades you can adjust parameters to give close to this effect. If you want it to be hot and extremely responsive you can adjust this. I find it much easier and faster to tweak a hei to the way I want it to fly. To boot the reduced maintenance cost and better reliability is a also enjoyed. I can chage configurations to change for the type of flying I am trying. I'm not a expert 3D flyer I just love to fly and experiment and get better. You can do this on any good heli system. But I enjoy the more connected feeling I get with flybarless and the flight characteristics, flexibility and stability I get using a flybarless stabilization unit. With the cost at $330 I have converted two of my fleet this way and won't turn back. I will still fly a flybarred and enjoy it but my preference is now FBL.

[HeliFlightCenter]

The second test flight of the SJGD by Italian pilot - looks pretty windy
http://www.youtube.com/watch?v=d-sujkM7XpE&feature=player_embedded

[stolpe]

Going to buy the new V-Bar with the rx connections soon to my T-Rex 500ESP. Can't wait...
Just bought the black RJX head from Helidirect, it's going to be a super cool heli. Hope it flies like you all have described. :clap: :clap: :D

/ Stolpe

[DALEPABAJO69]

Well I've just recently installed my SK-360 w/GP750 tial gyro in my Trex 500,had a hard time understanding the settings and getting use to flying flybarless,it's hard to get rid of old flying habits.But with the SK-360 she flies very nice and stable,I'm the one that has to get use to this new gyro that does all the correcting for me. It feel's kinda wierd actually.

this is my set-up:
Trex 500 w/belt tail drive
3 Savox 1257 ciclic servos = Align 520
Align GP 750 tail gyro w/fut.9650
BL-500L motor
BL 75G
CC BEC 10A
Skookum SK-360
AR6000e reciver
3-D PRO main blades