Rotorhead and 2-per rev shake

[barnstorm2]

My 2-place side by side AC running dragon wings has a slight stick shake.

It does not seem too annoying to me.

I have not done any work yet to check my blade tracking.

However, I did something while flying I have never been able to do before..

I turned around while flying and looked up at my mast and rotorhead. The side by side allows this to happen as the mast is on my right and not directly behind me.

What I noticed is that the rotorhead shakes.

Is this normal?

[MikeBoyette]

Tim, what rotor head are you running? Give Dad a call he can give you some ideas. He made it home from Mentone today so you can give him a call tomarrow.

[GyroRon]

Turn around or look up on any gyro in flight and you will see they all shake up there! Don't look at a RAF or other heavy two seater head in flight cause they move so much it will scare you!

[barnstorm2]

Thanks Mike and Ron! I will and it did!

[KenSandyEggo]

Ow cont-rare, Ronny. My lead-sled-head with SC blades hardly moves at all. Barely at all after I center them precisely. A little after a few months flying, but still a very smooth ride. I re-center them a thou or two and smooth as a silk sows ear....or something like that.

[barnstorm2]

My rotorhead is from AirCommand.

I run my Dragon Wings on the second hole from the bottom as that is the only one that seems to give the proper room.

I am under the impression that I must have taller towers to try the other holes.

[Harry_S.]

I agree with Ken.

I still use RAF blades and once you find the "sweet" spot...which involves tracking, pitch and chord adjustments...you're in. As Ken knows, this may be whistlin' in the wind, but, I'm gettin' close. I have NO head shake after I get above about 80-90 rrmp.

Most RAF blades are not perfectly balanced. :rolleyes: So, consequently, I finally am making a concerted effort, involving minute adjustments (.001-.005) to see how close I can come to a *smooth* ride. Right now, I have the best ride in the 6 plus years I've been flying my ship.

I'm looking to improve the ride...even more. ;)

[barnstorm2]

Harry, Ken,

PLEASE give me some details on how you have been making these adjustments!

Are you adding weight to the blade tips?

Are you shimming the head somehow?

Are you leaving free space between the tower bearing to let the rotor slide on the teeter (Jesus) bolt?

Are cheerios actually donut seeds?

[KenSandyEggo]

Tim, the SC blades come ready to fly out of the crate (after assembly). You don't have to string them as they have bushings to allow natural stringing and tracking (the bigger ones). They're balanced and pre-flown. All you have to do is mount them and center them between the towers. I don't have any click-clacking between the towers. Cheerios are actually hemmerhoid pillows for grasshoppers to sit on.

[automan1223]

Ken,

what kind of bushing is it ?

Rubber ?
Polyurethane ?
Poly graphite ?

hard ? soft ?

Jonathan

[KenSandyEggo]

Elastomeric (sp?). I think it's all on their website. I can't recall right now...nor what I ate for breakfast this morning.

[birdy]

Tim,
when I changed from the RAF blades to the extr alum blades I found a nasty supprise.
The new blades were @ 9" out of track.
After some shimming ,I found I needed to shave 17th off one side of the block to counter the crooked RAF head :mad: and get them to track together.Now they are as smooooth as silk. :) and no head shake,at all. :D

[MikeBoyette]

Tim,
I just taked to Dad he says that is normal for a set of blades that big. Be glad your mast is limber enough to take most of the shake out. If you had a real stiff mast then you would have all that shake in the stick. If It really concerns you I'd go with a slider head.

[barnstorm2]

Thank you Mike!

Please pardon how nieve I am but could you tell me about slider heads and if you sell them:

how much they would be?

Would I need to re-hang test or change cheek plates?

[MikeBoyette]

Tim,
I hope RFD is the only one selling them. The Slider Head is my father's design and if anyone else is selling them as their own then they are stealing. It has a system in the head that enables the head to move fore and aft a little bit. The system has springs that dampens the thump the blades take when they are broadside to the wind. Any way the end result is less shake. Give Dad a call he can explain it better than I since he is the designer and I just a dumb phone man.

[Mike Hook]

Tim

If you talk to Ernie about the slider head post what you find out. I am interested in what ever takesssssssss the shake out.

Mike

[GyroRon]

eveyone was kung fu fighting................. those kicks were fast as lightning!

Mike you not the dumb phone guy, your Mike. Ever watch the show " American Chopper" ? there is a Mike there too, and you remind me of him. Your dad isn't as mean as that Mikes dad!

[quadrirotor]

it's a french design!
http://www.averso.info/tetrotor.html

[CLS447]

Tim, Tim, Tim, Where have you bin? Ernie has had the slider head for a while now! I think it is about $1000. Carol Degraws Dom had Dick D.'s version of one on it. That was the smoothest ride under DW's that I ever had. Didn't you see Ernie's new head with the tall towers, spreader bar & teeter stops? Very nice, just don't know if I need it yet($). I didn't even ask about it yet but I like the looks of it! You should have spent some time at the RFD tent. Always something good under there. You gotta pick Ernie's brain when you get the chance.I at least got my yellow RFD shirt.

I wished I could let you try my SC blades before you go that way. The bushings are like a slider head built in. But I'm sure the slider head would help especially with that triple stiff mast we have!

I was surpised to see sliders on the Sparrowhawks since they are already using the SC blades.

Check out this head that my mentor made! I feel like a dummy when I speak with Dick D. !!!! :confused:

[barnstorm2]

Chris,

I was aware of the tall tower advantage of the RFD head but was unware of the additional benifits. The stick shake is not bad at all but what scared me was when I turned around and saw the rotorhead shaking.

I do own one of the yellow t-shirts. I bought it at Bensen days. I tend to where motorcycle T's to gyro events and gyro T's to motorcycle events.

[CLS447]

Here's Dick Degraw & me taking Carol's machine up for a test flight. Carol asked Dick to check out the brakes for her.A very memorable flight, thanks Dick.

Dick needed some technical advice from me :rolleyes: ! Yeah Right!

Check out that rotorhead!

[RICK MARTIN]

1. O.K. You guys are scaring me! At Ron's advice, I opted to have my Brock head rebuilt even though I bought a pair of 24' Dragon Wings to put on it. Now I'm hearing all this talk about stick shake with the DW's. Am I in for a problem?

2. By the way, the upper unit of my pre-rotator (like Ernie told me it might) does conflict with the bottom of the blade straps. His solution was to slightly trim the top of the pinior gear shaft. This will still only give me about 1/16 of an inch clearance between the strap bolt and the bronze housing of the pre-rotator shaft. This makes me nervous, but the only other fix I can see it to shim one of the head components. Has anyone else already been through this problem or does anyone else have any other ideas for a fix?

[Aussie_Paul]

A lot of those bronze housings have been "trimmed" to allow clearance. If the hub bar or straps hit that bronze housing in flight the situation is beyond redemption.

We had a guy about 12 years ago roll his machine over and that bronze housing broke. When he rebuilt it he made a very strong steel housing. He put McCuchens on it and did not check the clearance. He flapped his blades badly as he took off and a few seconds later at approx 150' the McCuchens departed the gyro :eek: and the guy and the airframe fell. His mate had told him to just hop it to see if there was the usual McCuchen shake. This guy was not one to be told!!!!

What happened was, one of the blade to hub bar attachment bolts hit the steel housing when he flapped the blades. This cracked open the torque tube, but not enough to let the blades go untill he got to approx 150'!!!!!!!!!!! After that it was all over.

He had a pre rotator, and boy it must have felt severe through the control stick as that damage was done to the torque tube.!!!!

Aussie Paul. :)

[MikeBoyette]

Rick,
Not to be concerned the shake that everyone is talking about usually only occurs when your flying iron. Your little machine should have little to no shake.

Ron,
There is no agreement between AAI and RFD. Their version of the slider showed up on their machines at BD's. Enough said.

[RICK MARTIN]

Paul & Mike,

Thanks for the info guys. Makes me feel a little better.

- Rick

[GyroRon]

Gooney goo who

[MikeBoyette]

Ron,
I agree, but you are opening a can of worms that is better off left closed.

[GyroRon]

OK, can of worms back uinder ground. I erased my posts about the you know what on the you know whats.

[MikeBoyette]

Gooney Goo Goo to you too. That's funny I haven't heard that in years. Not since Eddie's aunt fell down the stairs and his uncle said "Now That's A Fire!"

Oh Yeah Andre' The slider head is french, because if you did not noticed Boyette is french

[Brian Jackson]

Quick question:
Being fairly new to gyros and unfamiliar with rotorhead designs, when removing the blades for transport, do they have to be tweaked again for precise alignment when re-attached? Or is that a function of the head that only needs to be adjusted once for a particular set of blades (like a memory lock?) Thanks,

Brian Jackson

[Ralph]

Brian,

Toward the back of your Gyrobee documentation you should find a section on "Rigging Your Blades" or something to that effect. That should answer most of your questions.

Ralph

[KenSandyEggo]

Just a thought, but if there's a French version (I think) and a DeGraw version of the slider, why shouldn't AAI have a version? It seems it's either not a patentable idea or wasn't patented. I'm trying to only let one small worm slink out of the can and not stir up stuff and get it back in there quickly. Did your dad invent it Mike, or were there other versions or attempts before his? Did he think of patenting it, or is the cost just not worth it? I believe if someone comes up with a unique product and fails to patent it, it's fair game for everyone else to make their version of it and the inventor isn't entitled to any hard feelings. That's my kindly 2 cents anyway, but then I probably don't know all the facts.

I think AAI was going to use a bushing similar to RAFs, but supposedly RAF patented it. How you can get a patent for a giant rubber washer around a bolt to soften movement is beyond me. Aren't there hundreds of those thing on every car on the road....called bushings? You can send me a private message if you care to Mike and if you don't want to discuss it here....or not. :)

[quadrirotor]

that's it!...
French Averso head.

http://www.averso.info/

[RICK MARTIN]

Paul & Mike B. (and everybody else!)

Regarding my earlier concern of the strap bolt hitting the pre-rotator upper unit: I trimmed the pinion shaft and the top of the bronze housing. You think this clearance is alright?

[GyroRon]

Looks close but looks like it should work. You can always further reduce the amount of teeter the hub bar can do to insure the hubbar never hits it. To do this is kinda easy, but I will let you and Ernie work that out. It involves modifications to the Hubbar - not something you want to do wrong!

[RICK MARTIN]

Ron,
Thanks for your response. Can you explain what you are talking about so that I can decide if I want to bother Ernie or not?

[GyroRon]

Basically you are adding a small piece of aluminum plate - like a 1/8 inch thick or so to the bottom of the hub bar where it contacts the rotorhead when you pull the hubbar down like you did in that pic. The extra piece you add limits how far down the hubbar can go, therefore giving you more clearance. In absolute on the edge flying this may be a problem cause it will let the hubbar basically bottom out on the teeterblocks sooner than it is all designed to do, but who flys that far on the edge? Not me :)

[RICK MARTIN]

Thanks Ron,

I thought that was what you meant. I think I'll go with this for a while. If my head/blade combo is smooth enough then I may go a little further just for my peace of mind.

[MikeBoyette]

Rick,
Give Dad a call about that. I am no authority on rotorheads. You won't be bothering him . That is what he does.

[RICK MARTIN]

Mike,
I'll go ahead and do that. Can I email him that picture? Or can he see it on your computer instead of me driving up there or trying to describe it on the phone?

[MikeBoyette]

Rick,
He can see it on his own computer it will take him a while for the picture to download. He is still on dial up. We (Verizon) do not have DSL in his area yet. He can not see it on my computer we live about 30 miles from one another. I live in Brandon, which is considered town. He lives in Wimauma, and that is about as country as it gets. My Dad hates coming to town so I doubt he'll ever have a reason to come to my house.

[RICK MARTIN]

Mike,

That's great. I'll reduce the image before I send it to him. What's his email address?

[MikeBoyette]

rfdlouie@att.net

[Aussie_Paul]

Ron, it is better to glue some 1/16th" neoprene/plastic to the underneath of the hub bar as teeter stops. I had to do that to all Rafs. If set up the way the Raf manual tells you, the prop and rotor overlap by 2". Raf had something like 20 degrees of teeter!!!!! and 22 degrees of back stick. :eek:

At the moment on Hybrid I am running 15 degrees. That is not a problem with a heavy machine that can't change direction quickly and gbet too far ahead of the rotor.

I have drawn a line how I used to cut the bronze bracket t an angle.

Aussie Paul. :)

[RICK MARTIN]

Thanks Paul. Very helpful.