minimum airspeed in your gyro

[All_In]

... Is there a sound track for this?

I think Ron had to buy the sound track from a blackmailer and destroyed it.... something about incrimination or evidence IIRC. :noidea:

 

[PalmPilot]

Here's a good educational video on understanding Mast bumping, flapping & Low G's... Apparently where the phrase " Treat the cause & not the symptom" came from...
Note: long video...YouTube - Mast Bumping - Causes and Prevention

Mike

 

[GrantR]

How was a 20 min video uploaded to youtube? I though 10min was the limit.

 

[MichaelBurton]

I am glad you warned me that it was long so that I could bring lunch and a pillow.

 

[All_In]

@Mike
I learned from that, thanks!!!

 

[Resasi]

Good video, thank you.

 

[SideKick]

It also broadened my understanding, thanks

 

[GyroRon]

I was told to never allow the blades to go slower than what they turn at the point of lift off. With the old engine the gyro would lift off at 260-270 RRPM, and I could easily get the rotors to 270 in flight by holding the airspeed at or close to zero and at high power setting. The gyro now lifts off about 275-285 rpms and I have again seen 270 in flight with only about half throttle and zero airspeed. I am afraid to see how slow I can possibly get them to.....

 

[birdy]

Birdy if you get the blades too slow, they loose their stiffness and you can flap them
Then flapn is the rong term Ron.
Fold would be more accurate.
but i dout that would be possable.

But in my own gyro with the long rotors and the amount of thrust my engine produces, it is very easy to slow the rotors to a rpm lower than the lowest rpms shown at lift off. I have avoided allowing them to go any slower as I was warned by the manufactor of the blades that at this slow of a speed they loose their stiffness and can flap or even buckle.... bad things would happen in other words.
A rosco witha a 912 is hardly a slug Ron, and iv spent hundreds of hours at full tap, just before sink, and iv never floded or buckeled a blade yet.
Like i said, it aint possable.
Wot is possable is over stressn the hub bar through too high a cyclic rate for the low rrpm if the machine pitches too fast.
Besides, CB says that a rotor can regain flyn rpm from as low as 50% normal rpm without too much hassle. Thats alot slower than the regular "horse it off" rrpm.

But what your saying is no matter how powerful your engine, nor how light your blade loading is, you can pull back stick and slow to zero airspeed at full power and there are no issues to be concerned about?
Been do'n just that for years Ron, And hold it at WOT, sinkn steady, almost to the ground and never hada problem.

Everythns relevant Ron.
High loaded rotors will have high flight rrpms, high min rrpms, and high min lift off rrpms.
low loaded rotors hare the same.
Its the percentage of veriation that counts.
If the blades a set to fly XX machine at XX load, they gouvern the rpms that suit the variants.

I dont have the advantage of a rotor tac, so i cant give numbers, but a regular move the ferel goes through many times a day is,
top off from a virtical climb, level the disc [ horisontal] , apply full power and go strate into a full power virtical sink. Itd start loosen rrpm at the bottom of the climb, loose more at the top, more from the rapid, high cyclic at the top, and more still till the decent start to steady. mite b e a good thing i dont hava taco, coz id probably never do it again.
Yes, they are ' mushy' till the rrpm catches up, but iv never floded/flaped once.

 

[Fl90]

there's mushy.....and then there's MUSHY. I just got a machine with a rotor tach, and a bunch of other dials. I'm thinking of taping over them to keep my blood pressure down!

Phil

p.s. maybe a bigger rudder too.

 

[C. Beaty]

Whether or not a rotor will flap catastrophically depends upon airspeed and the angle of flow through the rotor disc.

During rotor startup, flapping would be eliminated if the rotor disc could be tilted back 90º so that edgewise flow was eliminated. It would either start or slow down.

 

[MichaelBurton]

Whether or not a rotor will flap catastrophically depends upon airspeed and the angle of flow through the rotor disc.

During rotor startup, flapping would be eliminated if the rotor disc could be tilted back 90º so that edgewise flow was eliminated. It would either start or slow down.

I guess I don't quite understand what you are saying.

Please explain

 

[getut]

Sounds like he's saying that if ground and tail behind the gyro weren't the limiting factor and you could rotate the blades back all the way (think drag chute or a gyro in a vertical descent) where the advancing air was hitting the bottom of disk straight on rather than mostly edge on like a normal takeoff.

 

[C. Beaty]

I guess I don't quite understand what you are saying.

Please explain

A rotor will recover from lower rpm in a vertical descent than with translational airspeed.

 

[MichaelBurton]

A rotor will recover from lower rpm in a vertical descent than with translational airspeed.

I understood that and have seen it many times.

What I was having problems with was that 90 deg. Statement but now I think I understand. If the disk were tipped back far enough it would be the same as a vertical descent and there would be little or no flapping required as there would be no difference in the air velocity over the airfoil induced by the movement of the gyro. That is intuitive to me but I did not see how it would be applied to the situation of a low G flapping / mast bump event. Thanks for the graphic.

 

[Redbaron]

sorry for not respondin, had a stomach virus for a few days and felt like crap. the airspeed specs on my bee aren't much off from ralph taggarts original bee! this isn't voodoo lol my disk loading is light! ron your welcome to come over anytime, pm me when your free. it will fly slow under power maybe It was 10-12 mph hell I don't know its pretty neat to go that slow tho! got some rotor shake above 35mph, need to clean those bugs off. she doesn't like to go real fast thats for sure :wacko:

 

[Redbaron]

I only went that slow under dead calm conditions! fly fast in strong thermals then you might see your rotor tach dance! :smokin:

there's mushy.....and then there's MUSHY. I just got a machine with a rotor tach, and a bunch of other dials. I'm thinking of taping over them to keep my blood pressure down!

Phil

p.s. maybe a bigger rudder too.

 

[RotorTom]

Is it me? Or does he just not make any sense?

 

[Fl90]

Just doesn't have a solid understanding of the gyro.

Best thing to do is keep him in discussions and feed him info as politely as possible. He is already flying, and this is a good source of information for him. We just need to keep him reading till it sinks in.

I hope I don't have to contribute to the flower fund.

Phil.

 

[Redbaron]

sounds like you need some more brain food, I have a good understanding! you have been brainwashed by those " unstable gyros" that they are super unstable and dangerous lol

Just doesn't have a solid understanding of the gyro.

Best thing to do is keep him in discussions and feed him info as politely as possible. He is already flying, and this is a good source of information for him. We just need to keep him reading till it sinks in.

I hope I don't have to contribute to the flower fund.

Phil.