RunRyder RC
WATCH
 4 pages [ <<    <     1     ( 2 )     3      4     NEXT    >> ] 9818 views POST REPLY
HomeAircraftHelicopterFlybarless Rotor Head SystemsSkookum › Skookum SK-720 Flybarless System
04-05-2010 12:21 PM  8 years agoPost 21
Ronald Thomas

rrMaster

Gainesville, Fl, USA

My Posts: All  Forum  Topic

Out of all the FBL systems I've flown(including the V-Bar), its pirouetting performance is probably the closest I've felt to a standard flybarred machine.
So what are you saying exactly? As we all know pirouette optimization is a feature VBAR and most other 3axis systems have that cannot be accomplished with a flybar as the tail gyro cannot "talk" to any other part of the system..............Ron

Team MikadoUSA 480XXTreme, 550SX, 600SX, 700XXTreme, 800XXTreme!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 02:19 PM  8 years agoPost 22
t2o

rrNovice

Pleasureville Ky

My Posts: All  Forum  Topic

I can not answer for asnybody else; but I can say in a very objective way, that the SK 720 does not suffer from precession (wobbly piro syndrom). It will piro, on axis, untill the gas runs out or the batteries go dead. Pretty much like my FB Predator (soon to be FBL Predator I migt add)

Cheers
Troy

PM  EMAIL  Attn:RR  Quote
04-05-2010 03:13 PM  8 years agoPost 23
Ben-T-Spindle

rrProfessor

Central Illinois

My Posts: All  Forum  Topic

I think that having accelerometers is the key. Looks like Vbar has some catching up to due.

... BTS

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 04:04 PM  8 years agoPost 24
iHover

rrVeteran

Berne , NY

My Posts: All  Forum  Topic

Hows the manual and software?
I had a SK 360 a while back for a Multi blade and had a very hard time setting it up. The manual that came with it was awful and the software was even worst. Has this gotten any better. Does the manual explain the settings in the software and how they affect the system and flight performance? On the sk 360 I couldn’t tell if the gain dials where working or the software was overriding them and vice versa .

You had me at Hover

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 04:49 PM  8 years agoPost 25
g_dmitry

rrApprentice

Edmonton, AB, Canada

My Posts: All  Forum  Topic

So what are you saying exactly? As we all know pirouette optimization is a feature VBAR and most other 3axis systems have that cannot be accomplished with a flybar as the tail gyro cannot "talk" to any other part of the system..............Ron
Piro optimization is about holding rotor disk leveled during piro. That's what regular flybar does naturally (like old good mechanical gyroscope), and it does not need to talk to tail gyro. But of cause flybar lucks "heading hold", it works in "rate" mode.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 05:03 PM  8 years agoPost 26
Ronald Thomas

rrMaster

Gainesville, Fl, USA

My Posts: All  Forum  Topic

The way I understand piro comp is it keeps the attitude of the heli the same no matter what the tail is doing IE doing piros in FF (control of the swash). The heading of the heli does not change with no correction needed. You can't do that with a flybarred machine without correction.

Team MikadoUSA 480XXTreme, 550SX, 600SX, 700XXTreme, 800XXTreme!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 05:09 PM  8 years agoPost 27
g_dmitry

rrApprentice

Edmonton, AB, Canada

My Posts: All  Forum  Topic

You can't do that with a flybarred machine without correction.
Sorry it is wrong. Flybar does that. As I said Piro optimization is about holding rotor disk leveled during piro. But note that flybar is not "heading hold". This is the biggest difference.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 05:31 PM  8 years agoPost 28
Al Austria

rrElite Veteran

Davis, CA - USA

My Posts: All  Forum  Topic

Piro optimization is about holding rotor disk leveled during piro. That's what regular flybar does naturally (like old good mechanical gyroscope), and it does not need to talk to tail gyro. But of cause flybar lucks "heading hold", it works in "rate" mode.
Correct.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 06:17 PM  8 years agoPost 29
Ronald Thomas

rrMaster

Gainesville, Fl, USA

My Posts: All  Forum  Topic

Piro optimization is about holding rotor disk leveled during piro. That's what regular flybar does naturally (like old good mechanical gyroscope), and it does not need to talk to tail gyro. But of cause flybar lucks "heading hold", it works in "rate" mode.
Which is why you have to make corrections. In FFF with the nose pointed down, pirouette with a flybarred machine and you will need to make corrections to keep the heli heading in the same direction. With Piro comp, you will not..........Ron

Team MikadoUSA 480XXTreme, 550SX, 600SX, 700XXTreme, 800XXTreme!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 06:24 PM  8 years agoPost 30
g_dmitry

rrApprentice

Edmonton, AB, Canada

My Posts: All  Forum  Topic

At that point it is more about "heading hold" vs "rate mode" and not about Piro optimization. With heavy paddles almost no correction will be needed. Even with Vbar you heli setup should be perfect to get perfect piros in FFF with not corrections at all.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 06:28 PM  8 years agoPost 31
Al Austria

rrElite Veteran

Davis, CA - USA

My Posts: All  Forum  Topic

Building on what dmitry has already said, a mechanical flybar is attached directly to the rotor head and with that it is a completely "live" system. It's corrections are ALWAYS perfectly in phase and it is able to make the appropriate cyclic corrections regardless of the fuselage's yaw motion and/or position.

Among other things, piro-optimization is means to keeping cyclic corrections in phase during rapid pirouetting. Take it away and the you'll get the dreaded "wobble" in pirouetting maneuvers.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 09:18 PM  8 years agoPost 32
Stolla

rrKey Veteran

Port elizabeth South Africa

My Posts: All  Forum  Topic

"Piro optimization is about holding rotor disk leveled during piro. That's what regular flybar does naturally (like old good mechanical gyroscope), and it does not need to talk to tail gyro"

"It's corrections are ALWAYS perfectly in phase and it is able to make the appropriate cyclic corrections regardless of the fuselage's yaw motion and/or position"

Not true, flybar does not make corrections, it merely acts as a stabilizer due to centrifugal force like a bicycle wheel for instance.
That's why it will wobble around its own axis if you piro in fff as it can not make correction for the constant elevator input, small as it may be
In contrast to that any standard vbar setup will do perfect piro's in fff, So i cant see how you would want a flybarless heli to "feel" like a flybarred one
Just throwing my 2 cents as it seems there's some confusion about piro optimization vs flybar or units w/o piro opt

Common sense may not be common after all

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 09:28 PM  8 years agoPost 33
g_dmitry

rrApprentice

Edmonton, AB, Canada

My Posts: All  Forum  Topic

Not true, flybar does not make corrections, it merely acts as a stabilizer due to centrifugal force like a bicycle wheel for instance.
HH vs Rate...
So, no confusion here. Stabilization is correction too
That's why it will wobble around its own axis if you piro in fff as it can not make correction for the constant elevator input, small as it may be
Hmmm.... My Flybared helis never do wobble in fff or in piroloops. Yes, you need to correnct them (due to "rate" mode), but they do not wobble. So, thats not true.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 09:47 PM  8 years agoPost 34
Ronald Thomas

rrMaster

Gainesville, Fl, USA

My Posts: All  Forum  Topic

Piro opt = No corrections

Flybarred = corrections

No matter how small they may be, they are needed. I can do them with no hands on the right stick....you can't. Thus the advantage of piro optimization ..........Ron

**** Sorry OP for the temporary hijack ******

Team MikadoUSA 480XXTreme, 550SX, 600SX, 700XXTreme, 800XXTreme!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 09:56 PM  8 years agoPost 35
g_dmitry

rrApprentice

Edmonton, AB, Canada

My Posts: All  Forum  Topic

Piro opt + flybarless stabilization (HH) + perfect setup = No corrections
Piro opt + no flybarless stabilization(no HH) = Lots of corrections

Piro opt itself does not keep your heli leveled. It works in conjunction with flybarless stabilization system which holds heli leveled. It works similar to tail precomp. Precomp fixes tail twitches on hard collective/cyclic input, but gyro holds tail in same direction.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 10:08 PM  8 years agoPost 36
Ronald Thomas

rrMaster

Gainesville, Fl, USA

My Posts: All  Forum  Topic

That's why it will wobble around its own axis if you piro in fff as it can not make correction for the constant elevator input, small as it may be
In contrast to that any standard vbar setup will do perfect piro's in fff, So i cant see how you would want a flybarless heli to "feel" like a flybarred one
My point exactly. A lot of "American Pilots" complain that a FBL heli does not "feel" like a flybarred one. They are not supposed to and never will with added features like Piro Opt and such. IMO I think it is more the pilot than the system that is unable to perform I bet if a young pilot flew FBL helis from the start, he would be able to do the "transitions" or the "down low" stuff because his timing would be adjusted to it. Guys that have been flying flybarred helis for most of their R/C life will automatically dismiss it as "funny feeling" because they are just not used to it. My opinion totally of course ........Ron

Team MikadoUSA 480XXTreme, 550SX, 600SX, 700XXTreme, 800XXTreme!!

PM  EMAIL  GALLERY  Attn:RR  Quote
04-05-2010 10:20 PM  8 years agoPost 37
ZZ3Astro

rrVeteran

Panama City, Fl

My Posts: All  Forum  Topic

I looked on their site for a manual for the 720 but nothing seemed to exist yet. I'm trying to figure out how the receiver part of this thing works. Do you buy satelite recievers from you preferred manufacturer or are you limited to just a specific one such as Spektrum? Where do I get them and how much? Does this unit have a large gauge input that comes directly from a 2s lipo? And does it regulate the voltage output to the throttle and tail servos?

This seems like the ideal way to go, one box that does almost everything (sure wish it had a gov and mixture control!) for less money than buying three or four separate parts.

Aeolus 50 3D CF - 8FGH/R6008HS - GY520/BLS251 - BLS451 x 3 - Multigov - S3155 - YS56

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
04-05-2010 11:45 PM  8 years agoPost 38
iHover

rrVeteran

Berne , NY

My Posts: All  Forum  Topic

Yea thats what I was trying to find out before it turned into a piro optimazation clinic

You had me at Hover

PM  EMAIL  GALLERY  Attn:RR  Quote
04-07-2010 07:37 AM  8 years agoPost 39
Al Austria

rrElite Veteran

Davis, CA - USA

My Posts: All  Forum  Topic

Not true, flybar does not make corrections, it merely acts as a stabilizer due to centrifugal force like a bicycle wheel for instance.
The flybar works off of the same principles of a gyroscope, centrifugal force has nothing to do with it.

On a flybarred helicopter, when an outside force(ie wind) acts upon the rotor disk and changes the plane in which it is spinning, the flybar will maintain its original plane and automatically feed in the appropriate cyclic pitch to counter the rotor disk's movement. Now I may just be arguing semantics but IMHO, this is a correction.

A mechanical flybar is mounted to the rotorhead, therefore it is REVOLVING WITH the rotorhead. It works completely independent of however the yaw-axis of the helicopter is oriented and thus, its corrections are never out of phase.

The problem with an electronic flybarless system is the fact that they are mounted to the FUSELAGE of the helicopter. Now, unless the system has "knowledge" of what the yaw-axis of the helicopter is doing, rapid pirouetting will naturally induce a certain amount of cyclic phasing error and you will experience cyclic "wobbles". On a 3-axis flybarless system, the yaw-axis portion of the system can feed data regarding angular velocity/tail position to the other two axes and keep them "oriented" if you will.

I believe people are getting confused to think that the function of piro-optimiztion is something that is beyond what a flybarred helicopter is capable of doing, when in fact its primary function is to replicate a dynamic OF a flybarred heli. A flybarred heli CAN maintain its rotor disk's attitude whilst pirouetting, however things like flybar ratios, paddles, fuselage drag, can effect the performance here. The thing about an electronic flybarless system is that they are not affected by the above variables and have the serious advantage of ELECTRONICALLY maintaining the rotor disk's attitude. As dmitry puts it, it is a form of "heading hold" for your rotor disk.

PM  EMAIL  GALLERY  Attn:RR  Quote
04-07-2010 09:14 AM  8 years agoPost 40
Stolla

rrKey Veteran

Port elizabeth South Africa

My Posts: All  Forum  Topic

A mechanical gyroscope works because of the centrifugal forces of the spinning member within. Flybar does basically the same, therefore you can instead of flybar use a weighted bar which will stabilize the heli.
Different flybar ratios paddles etc will give different performance attributes but the issue here is that someone not clued up to the differences between a good flybar setup and vbar setup may think you can achieve with a flybar what you can with vbar.
Remember were talking piro optimization and theres just no way you'll get the flybar to do piro optimization in fff, as dimitry mentioned he makes the correction to keep it level, which is why i said the flybar does not make corrections for you (yes it does exert the centrifugal or gyroscopic forces on the different mechanisms involved and yes you can tweak it do do many things) So not to get in a technical pi...ing contest the bottom line is that a flybar wont make corrections for you in fff whereas vbar will.

Common sense may not be common after all

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 4 pages [ <<    <     1     ( 2 )     3      4     NEXT    >> ] 9818 views POST REPLY
HomeAircraftHelicopterFlybarless Rotor Head SystemsSkookum › Skookum SK-720 Flybarless System
 Print TOPIC  Make Suggestion 

 22  Topic Subscribe

Friday, August 17 - 10:23 pm - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online