FBL without a FBL unit ??

[eltreato]

Originally Posted by KiloXray

The is a dude named Uriah, here on HeliFreak, that flies a Nobar Blade 300X. I believe he is good enough with it to do piroflips. Its pretty impressive.

Look him up!

Yup that was a great thread, Uriah did really well without the FBL:

https://www.helifreak.com/showthread.php?t=616139

[Mr.HillBilly]

I flew my G20 with no FBL controller for a couple of months, fast flight was a bit touchy but slow flying and flipping around and such it did fine. I was using FBL blades so that helped a bit. Flying in the wind is not much fun also.

[myxiplx]

Originally Posted by peteski

Does anyone know if you can effectively "no bar" sim helis? I'm using NeXt.

On some sims you can apparently set the virtual FBL gains to zero on the cyclic to achieve a similar effect. Not sure if next has that though.

[peteski]

Originally Posted by myxiplx

On some sims you can apparently set the virtual FBL gains to zero on the cyclic to achieve a similar effect. Not sure if next has that though.

Cheers, I'll have a look as a little project.

[trillian]

I had a Rave Ballistic that I flew a little bit with no FBL. It was not really much different in a hover with no wind but the slightest wind and you're constantly correcting. It was more naturally stable than I expected but you quickly realise what you take for granted with a FBL unit.

[HB870]

Well I just tried nobar with my new Blade 550X. I had a bad FBL unit and wanted to try it out. I put in a old 7100rx and a old 240 gyro and set it up. I only tried it in my yard but it was like a rock. It was a little gusty but it seamed good to me. It just started to rain so I only ran the one battery. I have never flown a flybarless heli with a FBL unit so it was like any other heli to me. Way better than my old FBL GMP's back in the 80's. This is also the biggest electric heli for me so far. I just had to try it out. I will have to give it a try at the field when it stops raining.
HB870

[eightythree]

Great !
This winter I will Frankenstein a 450 together and go NoBar for indoor hover/FF. My goal is lowest possible HS.... should be interesting

[quinn]

I've always thought running nobar would be a good way to determine the optimal phasing for a head design. With fbl gyros, it would be hard to tell if your phasing was off a couple degrees because it will compensate, but with nobar, you should be able to see it drift with continuous flips or rolls. It's always assumed that phasing is exactly 90 degrees, but if you dialed it in exactly where it should be, then add fbl stabilisation back in, it should fly even better than before.

[cycled]

I've always assumed flybarless controllers should be able to tune themselves for optimal phasing. Whether they do or not I have no idea!

[myxiplx]

Originally Posted by cycled

I've always assumed flybarless controllers should be able to tune themselves for optimal phasing. Whether they do or not I have no idea!

I don't believe they tune themselves as such, but the nature of how they work is that they'll automatically react and correct any issues.

It won't be perfect, but they're so fast it's unlikely most of us would ever spot it

[dogbreath]

Long ago I tried FBL/Nobar on my SJM430 (into the wayback machine, Sherman). It hovered fine, had lots more power, but as soon as I tried some harder maneuvers it got into a feedback oscillation and I turfed it. I then bought an SK360, repaired the beast, and was much more successful.

Dan

[extrapilot]

Originally Posted by quinn

I've always thought running nobar would be a good way to determine the optimal phasing for a head design. With fbl gyros, it would be hard to tell if your phasing was off a couple degrees because it will compensate, but with nobar, you should be able to see it drift with continuous flips or rolls. It's always assumed that phasing is exactly 90 degrees, but if you dialed it in exactly where it should be, then add fbl stabilisation back in, it should fly even better than before.

How would you correct phasing mechanically when effectively no FBL head has provision for swash follower bias? With some FBLs, it may be possible to dial the gains down so that you have no real stabilization/cyclic correction in place, but access to electronic phase angle adjustment. Maybe that is what you meant- that NOBAR is the same as 0 gains on cyclic. And, it may be- depending on how your FBL gains work.

[extrapilot]

Originally Posted by myxiplx

I don't believe they tune themselves as such, but the nature of how they work is that they'll automatically react and correct any issues.

It won't be perfect, but they're so fast it's unlikely most of us would ever spot it

Most FBL cyclic logic is not HH; it has a decay term, so it wont correct an error. The hope is that it can implement enough correction quickly enough that the pilot’s workload is greatly reduced.

Cyclic input has some delay at the rotor (takes time for the rotor to track a changed swash angle). And, the FBL requires time to detect chassis pitch/roll, and then to implement servo motion to correct the detected error. So, some error sneaks through. With FBL, significant phase error is not apparent with minor cyclic input/rates- where, for example, a hover to a slow forward departure would be managed well enough. But, phase error it is still apparent in hard cyclic maneuvers, where the FBL chases its tail; you can get some weird wobbles, or problems with yaw (i.e. a pure flip may end up with a few degrees yaw error- which is actually caused by a roll component from the phase error during the flip…). People are used to it- very few people run phase angle adjustment in their FBL. Its like driving a car with bad suspension geometry- you get to thinking its handling is normal, then maybe even good… And then, someone who knows how to tune the suspension gets to it- and you wonder how you drove the thing before…

[HB870]

I went to a heli funfly today and flew my 700 T-rex with a flybar. It was not as stable in hover as my 550X Blade that I test flew the other day without a FBL unit in it. That makes no sense to me. They have the same servo's and the 700 has a flybar. I am going to play more with the nobar before I install a new FBL unit.
I know that there are a lot of other inputs, the hiller steering, blade weight etc. but I was not expecting the feel that I got.
At least this hobby is not boring. And it's fun.
HB870

[Bladefx]

I converted a swift 550 to no-bar years ago...I added electrical tape 1" from the blade tips "about a grams worth" and used plastic blade grips with med/hard dampers.
it really improved the way it flew, it was responsive and felt locked in. I didn't notice any bad behaviors except for windy days it would get a little pitchy.


I didn't get to try a fbl unit until years later and when I did I was somewhat disappointed because it only made a difference on windy days.