docsparklin

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Recently acquired a Robbe Whopper Autogyro with a .60 2 stroke engine but I don't have any specs or instructions. Have read several posts about the "string on the tail" thing, the tendency to roll left and the use of rudder for gradual turns but not sure about the throws, angle of blade pitch, etc. Am currently working my way through www.autogyro.com, great info there. This is my first gyro and am a little nervous about flying it.
In addition to specs, can anyone give me some hints about how to check "airworthiness" and "readiness" of the Whopper prior to lift off to avoid a catastrophic crash? I would rather NOT fly it and keep it as a hangar queen than crumple it. My RC experience consists of about 25 planes, no autogyros until now. Thanks.

mnowell129

All accounts of the whopper was that it was fast, heavy, and needed a lot of power to even fly.
My vote would be to make a nice display out of it and buy something that's being manufactured
right now.

billf

There was an article in "RC Report" sometime in the 1992-1995 era about the Whopper. It talked about using a string to get the
rotor up to speed while taxiing etc. Perhaps the publisher of RC Report could supply a copy of the article. While I have no
personal experience with the Whopper, I think mnowell's comment is about right!

Bill

woopie

My Feedback: (6)

The Whopper was my first autogyro and she's a lovely flyer so long as you know what to expect. Be happy to walk you through the process even if you choose not to fly her.

David

docsparklin

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Thanks mnowell129 and billf. I really don't want to total the gyro if I can help it.
Woopie, do you have anything spelled out that you can share? The main thing is I need to know if she is airworthy as far as power, throw settings, etc. and what not to do. Any info you can pass on would be greatly appreciated.
I recall reading about standing on the string while the rotor comes up to speed, then disengaging the clutch while throttle is applied, letting her do her mild bank during climb and using rudder for the turns. I also read you don't want to hold flare on landing, lest you take off the tail feathers.
Anything else? Like head rotor rpm, etc.?
Thanks. Doc

BarracudaHockey

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Post some pics!

As someone that flys both helis and planes, I think it would be a hoot to try and autogyro!

woopie

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Rats, I timed out on my post and lost my reply.

woopie

My Feedback: (6)

Doc, I originally joined RCU to help someone else with a Whopper, but unable to find the thread.

I've also heard of the "string" method to hold the Whopper back while gaining rotor speed, but have not tried due to safety aspects. I prefer to have a clean/dry O-ring in the head drive and a 10-15 mph headwind. The only reason the tail feathers get damaged is due to a hard touch down on landing due to rotor blade flex, or a take-off rollover causing the rotor blades to swing back in their blade holders.

As to airworthiness; do you know the flight history of this Whopper, How does it look to you. If you are not familiar with helicopter rotor heads, or to be more specific, the Robbe/Schluter System 88 rotor head, I suggest you find someone who does. If not, I would look at and call ... http://www.ronlund.com/ ... as I'm sure they can be of help. The most important items to check and confirm are the main shaft, blade cross shaft/spindle shaft, control rods, ball links and flybar. The rotor head rotates clockwise and the rotor blades and flybar paddles should reflect this.

The original Whopper was supplied with wide under cambered rotor blades and latter replaced with a narrower/longer Clark-Y airfoil. I'm hoping you have the Clark-Y as it was a vast improvement in performance. Rotor blade appearance can say a lot about the Whopper's history.

The Whopper head speed has been Sky-Tached at 800rpm and has the visual appearance of a solid disc ... if you can see rotor blades you haven't got sufficient head speed.

This is only a start. I can supply you with copies of the original instructions and reduced size assembly drawings if you'd like.

David

docsparklin

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Here's a pic from a recent WarBird Fly In in Ft Worth. Had it there for static display only but had a LOT of people asking if it was going to fly. Hope it comes through. Uploaded but don't see any attachment message. Tried twice, let's see if we get 2 of the same pic or nothing.
Woopie, the blades are pretty wide and undercambered, covered in a white glossy adhezive backed material. Would appreciate any info you could send. Have some copter guys in the club that want to take a look at it but not sure if they need specs first.
Doc
[img]

docsparklin

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OK, 2 pics. Here is another angle showing the blades better and some of my other WarBirds in the background (blue P-51 and L-4 on the right). Looks like a fat blade, likely the original. Also have a boxed spare pair and covering. Doc[img][/img]

woopie

My Feedback: (6)

She looks to be in great shape. Has this Wopper been flown??? Have your helicopter friends check the Whopper after you recieve the instructions. Send me a PM with your address.

Sorry to hear you only have the original under cambered blades. The Clark-Y will be almost impossible to come by. The under chamered work, but need full power almost all the time. Not as easy overall as the Clark-Y.

David

docsparklin

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PM sent.
Doesn't look like she has flown at all. Can't find any signs of wear or tear other than hanger rash.
As I understand it, the maiden should be done naked: without the shell, not me! Just in case something unfortunate happens.
Doc

woopie

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Autogyros can have visual orientation problems and the fuselage will be a benifit. Sent you a PM too.

David

BarracudaHockey

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Very cool!

docsparklin

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Thanks. Getting her cleaned up and getting some GREAT info from Woopie. What a great resource on the Whopper!
Doc

woopie

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The word WHOPPER is indicative of the wonderful sound of the rotor blades in flight and not to be construed with the sound of a take-off roll over or bad landing ... which are not allowed! Otherwise she would be called the SMACKER!

David

docsparklin

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This thread has been quiet for a while. Our club had a Warbird Fly-In this Saturday. Took the Whopper and had a couple of heli guys check it out. Told them about all the caveats and we decided to have one of them fly it.
Good news, it flew twice. Bad news, not very well and not very far.
First crash loosened up one fo the tail feathers. Second flight took off tail feathers and bent the rudder connecting rod and broke it's attachment. Put a hole in the fuse.
Oh, well. See if I can repair everything.
Doc[img][/img]

woopie

My Feedback: (6)

The damage looks more like hard landings rather than roll-over take-offs. Did she fly at all? Was it a hot humid day?

One thing: I know the Whopper flys using the original blades, but it's work. If you get her back together I would consider making up a set of AeroBalsa rotor blades.

I never managed a flybar hole in the fuse.

David

docsparklin

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Yep. The 2nd flight was a nose up, started rigth roll, throttle back, land hard. All I could do was watch as he flew it. Then we would talk some more about *** happened. Will look more closely at the repairs needed, maybe try one more time. Need to figure out how to repair the fuse IF I get hte rest of it fixed.
Doc

woopie

My Feedback: (6)

What was the first flight like??? Did you have a head wind?

Your description of second flight is indication of just not enough head speed and a too-soon application of up cyclic & elevator that didn't help the head speed. If she did break ground, an immediate application of left rudder would have leveled the Whopper and more than likely the head speed would have increased enough to allow a climb-out. Without addiquate headspeed, cyclic roll just isn't there for a rapid leveling.

Did ya find the broken out fuse pieces? Fuse is made from PVC and can be best glued with PVC "water thin" solvent. PVC clear pipe cement can be used, but sparingly as it's slower to evaporate and will soften the rigid pvc till it does evaporate.

To reinforce a fuse crack, I'll lay a piece of 3oz. fiberglass behind the crack and apply PVC solvent and let dry. CA can be used but is brittle.

Check the pitch change rods and the swashplate plastic inner ring for damage.

docsparklin

My Feedback: (2)

Actually, there wasn't much of a wind. Still on the cooler side of the Texas morning. Lifted off, started the right roll and he set her down. My impression was that he was trying to get airborne too soon as the end of the runway neared. Next time will advise him to try a grass roll and stand on the string longer to get the rotors turning faster. Have the big pieces of the fuse. Will look for the thin solvent instead of the jelly.

woopie

My Feedback: (6)

That right roll is a prelude to disaser without a rapid left rudder. Dang, he was almost there.

Plastics supplier should have vinyl solvent. Sign makers that use rigid foam PVC sign board might also have solvent. www.mcmaster.com will have it.