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General control line discussion => Open Forum => Topic started by: Shultzie on February 27, 2008, 01:47:44 PM
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Check out this amazing Westland Wyvern Scale stunter by Brian Dyke from England..that Al Rabe discovered from an old magazine.
Keith Trotsle mentioned that the last issue of of Stunt News...has an article and plans are also availabe for any mere mortal who is brave or challenged enough to attempt such a project.
Yes, I pilfered this from Alfred E's website.
Great photos...of a great project.
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Brian Dyke and his Wyvern as well as his Stuka are outstanding examples of what a true craftman is capable of. Sadly, neither aircraft exist today and the plans are gone. Only the Stuka plans may be obtainable through the successor to Aeromodeller magazine. And yes, there is a great article with new pictures of the Wyvern and Stuka in the Jan/Feb 2008 of Stunt News.
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Dihedral. The scale work looks fabulous. Is that a Rabe rudder?
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Brian Dyke and his Wyvern as well as his Stuka are outstanding examples of what a true craftman is capable of. Sadly, neither aircraft exist today and the plans are gone. Only the Stuka plans may be obtainable through the successor to Aeromodeller magazine. And yes, there is a great article with new pictures of the Wyvern and Stuka in the Jan/Feb 2008 of Stunt News.
Al mentioned that the plans are still available....I'll check with Al.
That first photo is another model...of the Wyvern...but Al didn't mentioned who built that beautiful contra-rotation model WHICH I WOULD VENTURE A GUESS THAT OUR VERY OWN BOB HUNT COULD FIGURE OUT HOW TO MAKE AN ELECTRIC CONTRA-ROTATIONAL MOTOR WORK FOR STUNT? H^^ y1
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Check the Jan/Feb 2008 issue of Stunt News for the answer.
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Check out this amazing Westland Wyvern Scale stunter by Brian Dyke from England..that Al Rabe discovered from an old magazine.
Keith Trotsle mentioned that the last issue of of Stunt News...has an article and plans are also availabe for any mere mortal who is brave or challenged enough to attempt such a project.
Yes, I pilfered this from Alfred E's website.
Great photos...of a great project.
Don,
Interesting tha Al Rabe "discovered" thiis Brian Dyke Wyvern after the latest issue of Stunt News (Jan/Feb 08) appeared with coverage of the Brian Dyke aircraft The pctures of Brian with his Wyvern appeared in the July 79 issue of Aeromodeller. When Tom McClain started to research this airplane, Ian Russell, in England, was instrumental in making contact with Brian who wrote a nice article about his models and provided several more pictures that are in this last issue of Stunt News.
Don, please do not misquote me regarding plans availability. I mentioned on the SSW Forum that Brian had written that the plans for his Wyvern are not available.
Plans for his large Stuka were published in the December 76 issue of Aeromodeller and are still available. This is another large airplane, 72 inch span, and has the inverted gull wing of the full size Stuka.
Keith Trostle
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Exquisite model. Craftsmanship is awesome, the subject is outstanding. Another
fine example of what model airplanes are really about.
L.
"Carpe diem, quam minimum credula postero. (Seize the day, put no trust in the
morrow.)" -Horace
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There are several contra-rotating electric motor set-ups already commercially available! HiMax motors from MPI displayed four of them at the WRAM show last weekend!
Bob Hunt
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Randy Smith had a homemade counter rotating (fluid driven rear prop) .65 many years ago. It worked! From what I remember, it was on a *Magnum style* plane. Maybe Randy will correct my memories. (??)
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What we in CLPA need is someone to take Brian's pictures and tech data and reverse engineer the Wyvern for all to enjoy once again.
Tom
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AXI does make dual motor countra rotating propellor systems in a number of sizes. They have had them running at the Toledo show the last two years. They cause quite a stir... no pun intended.
Bob Branch
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Don,
Interesting tha Al Rabe "discovered" thiis Brian Dyke Wyvern after the latest issue of Stunt News (Jan/Feb 08) appeared with coverage of the Brian Dyke aircraft The pctures of Brian with his Wyvern appeared in the July 79 issue of Aeromodeller.
Keith Trostle
Keith,
If you are going to make a negative personal comment about someone, you should get your facts straight first. I "discovered" Brian's Wyvern when I bought my copy of Aeromodeller in July 1979, twenty nine years ago. Over the years I have posted the photo of Brian holding his Wyvern several times on Stuka Stunt Forum, usually when posting a group of semi-scale airplanes. A topic search should be able to confirm this. The bottom photo that Don "borrowed" isn't from the magazine, but a copy of a photograph Brian sent me when we were communicating shortly after I met him in 1979 during a London visit. Actually, we met at Glen Alison's home in Rickmansworth where I was invited to address a group of modelers about the molded construction of the Snaggletooth Mustang flown in the 1978 World Championships.
Meanwhile here is a complete page from that 1979 Aeromodeler magazine.
Al
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Exquisite model. Craftsmanship is awesome, the subject is outstanding. Another
fine example of what model airplanes are really about.
L.
"Carpe diem, quam minimum credula postero. (Seize the day, put no trust in the
morrow.)" -Horace
Good call Larry...It's a "Way Cool" design and I think we all enjoy this unique type of model.
Later,
Mikey
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Hello all,
Strangely enough, I've just pulled out the Aeromodeller with Brian's Stuka in! I remember judging a stunt comp. at Rochester airport in England, must have been around '74ish (can't be 100% sure, too much whisky has flowed through since then!) and Brian turned up with a Big Stuka, not sure if it was the one in the Aeromodeller? My fellow judge and I were very impressed with how smoothly it flew on long lines. He didn't win that day ( I think Pete Tindall did) but put up some superb flights. A fine model it was.
Cheers Neville
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Don,
Interesting tha Al Rabe "discovered" thiis Brian Dyke Wyvern after the latest issue of Stunt News (Jan/Feb 08) appeared with coverage of the Brian Dyke aircraft The pctures of Brian with his Wyvern appeared in the July 79 issue of Aeromodeller. When Tom McClain started to research this airplane, Ian Russell, in England, was instrumental in making contact with Brian who wrote a nice article about his models and provided several more pictures that are in this last issue of Stunt News.
Don, please do not misquote me regarding plans availability. I mentioned on the SSW Forum that Brian had written that the plans for his Wyvern are not available.Plans for his large Stuka were published in the December 76 issue of Aeromodeller and are still available. This is another large airplane, 72 inch span, and has the inverted gull wing of the full size Stuka.
Keith Trostle
Keith and Al...
PARDON MY "BRAIN FART MISS- QUOTE!
See what happens when one gets to be as old..blind deaf and dum-olddo as I am.
Not much of an excuse however, Guess I was so blown away by that great post of Al's on the web site...that I ass'-umed that the plan was still available on both the Wyvern and the Stuka.
Thanks for setting the record straight and always being there for us over all these years with your great memory and great archival skills and the toys airplanes that we so enjoy.
Again....I don't know why everytime I lurk on that "other website" I alway end up getting SOMEONE'S FEATHA'S RUFFLED.
Bottom line? I too should have read Al's wonderful post a little more carefully.
Great to see Stunt News bring back so many of those wonderful models of the past.
Don n' dumber...exiled here in Gig haaaba.
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Schultzie, don't feel alone. I think it is very easy to upset people over there. DOC Holliday
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I noticed that the author of the article said the model wouldn't outside well. I wonder if the model needed positive stab incidence to perform outsides.
With the high mounted stab, and the dihedral causing the effective stab height to be even higher, if positive incidence would have helped. As well as down and right thrust (if no contra-prop installed!). Since these models are near scale in configuration, it would seem the trimming techniques of full sized airplanes would come into play with even more effect.
Neat model, and with todays engines, trim and adjustable controls it would be a doable project that flies well enough for it's size and weight.
It just looks cool, that electric contra-prop set-up would the cats meow.
Chris...
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Very neat model. Thanks for posting Don!
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Like all of you I was blown away when I saw the Wyvern in Stunt news. It is such a stunning model and Brian's interpretiation did not leave a lot of room for imrovment.
Just curious: Did the Aeromodeler article include plans sheets? If so AMA plan service can do a credible job blowing up page size plans. To be sure the resolution suffers but the blow-up would be good enough for a reasonably capable draftsman to do as Tom M suggested and re-engineer it...
As I look back through my Dad's old picture books I feel said at how many really cool airplanes are there that can never be seen again because they were not published nor even had plans saved - makes it a wee bit tough to document!
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Aeromodeller magazine did not include plans for the Wyvern. Brian lost the plans for both the Stuka and the Wyvern in several moves from one residence to another. He now is into R/C exclusively and not interested in recreating his plans. He did say that the Wyvern fuselage was planked with formers on a horizontal crutch. The wing was built similar to his Stuka wing.
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Considering the extremely fine job you did in converting your big twin to CL Stunt, Tom,
you might be the logical guy to bring this subject to life as well. Your ship flies quite well, and
other examples like Al Rabe's semi-scale warbirds show that it is possible to make them work.
That said, a note on the counter rotating prop mentioned - if it is the same one that appeared
in Stunt News, I seem to remember that it was not driven, but a free turning flywheel hub, and the
setup responded to airflow and perhaps small friction to turn. My impression was that it was not
intended to be a truly functional piece, but merely an appearance item; a machinist having "fun".
Although the concept of counter rotating props seems like a good idea in terms of cancelling precession
and other torque effects, and the planetary gear mechanism is somewhat elegant, my assumption would
be that it might lack reliability, have fairly large mechanical friction, and also quite a bit of airflow turbulence
when the counter rotating props passed so close to each other in opposite directions. Tell me I'm wrong?
L.
"It isn't a calamity to die with dreams unfulfilled, but it is a calamity not to dream." -Benjamin E. Mays
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Although the concept of counter rotating props seems like a good idea in terms of cancelling precession
and other torque effects, and the planetary gear mechanism is somewhat elegant, my assumption would
be that it might lack reliability, have fairly large mechanical friction, and also quite a bit of airflow turbulence
when the counter rotating props passed so close to each other in opposite directions. Tell me I'm wrong?
L.
You're wrong! (no you're not, but I could not resist your invitation! >:D SORRY! :'()
All seriousness aside I think if we did this with "Smoke & Gears" (an IC engine & a gearbox) it would be complex and all the other things you mentioned. The more straight forward solution would probably be twin electric - but that ain't no cinch either!
Awhile back electric guru Keith Shaw built an (RC) electric Bugatti racer with two in-runner motors with individual gearboxes driving the contra-props. He tuned his system by monitoring current draw to each motor. When he started one motor was doing all the work the other showed barely any current draw and the bird was topping out around 60 MPH. After messing with gear ratios and props he got it so BOTH motors were drawing the same current, and the bird was now capable of speeds in the mid 80's.
I think we'd have to take the same approach with a stunter - monitoring current flows and balancing prop sizes and RPM to each motor until both were doing the same amount of work. Please note that we'd then have a "twin" that really wasn't a twin! Maybe add another small ducted fan in the Wyvern's scale exhaust port to jet sideways to generate extra line tension! (OK that's a stretch)
Uh, I'm not brave enough to repeat Larry's closing invitation!
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Hi Dennis and Larry ;D
The contra (counter?)-rotating prop I referred to was explained to me, by Randy, to be *fluid* (his word) driven, in other words, by air (his explanation). No gears. Or something like that.
I will see if Randy will reply to this. It was all late one night at a contest while several of us were standing outside at the motel.
Randy????? ;D
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As I look back through my Dad's old picture books I feel said at how many really cool airplanes are there that can never be seen again because they were not published nor even had plans saved - makes it a wee bit tough to document!
Hi Dennis,
My understanding is that with pictures and a statement from Big Art, the documentation is sufficient. No one that I know would doubt his word.
Bill <><
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Good Morning Larry ;D
You wrote
"That said, a note on the counter rotating prop mentioned - if it is the same one that appeared
in Stunt News, I seem to remember that it was not driven, but a free turning flywheel hub, and the
setup responded to airflow and perhaps small friction to turn. My impression was that it was not
intended to be a truly functional piece, but merely an appearance item; a machinist having "fun".""
~^
That is not correct, I have heard all this before many years ago, the people saying that were wrong then and wrong now.
The system did everything I had hoped for, It IS driven, and it completely eliminated the very bad G.P. I was having with the plane on large props. It also made the plane way more stable, and it turned corners harder and flatter.
As an added bonus it made the plane much more constant speed and killed any wind up.
The fluid drive (air is a fluid in this context) works on the exact same principal as you Automatic Transmission in your car, your car is NOT being driven by gears, it is being driven by fluid trying to be compressed , thus driving a vaned converter.
The rear prop went from 0 RPMs to 9100 RPMs in less than 2 seconds, and If anyone doubts its driven very hard, if you were to stick your finger in the rear prop while it is setting on the ground, It will take a large piece of it off.
I have held the rear prop still while the front one was running and there is a very large force trying to turn the rear prop, It take quite a bit to hold it still, the whole time it is wanting to rip loose from your hand....when you do let it go it goes to 9100 in a heartbeat.
I can send you references books to read about this if you care to. Or just ask anyone that knows about fluid dynamics/ fluid mecchanics. The concept is sound
Now the next comment is normally "yeah but it does,nt power the airplane" I will let you decide that for your self....a 7 pitch prop turning 9100 RPMs on the ground??? does this do anything? you decide.
However keep in mind I never needed any extra drive....Just an answer to the skinny fuse G.P. problem
The biggest problem was the rear counter bearing needed to be replaced about every 50 flights. It took a beating from being too small and the forces of near 18,000 RPM closing speeds.
Other than that it is a very bulletproof system
Regards
Randy
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You guys are gonna love this, I don't have the "Wyvern' plans, but I do have the "Stuka" plans. How you like them apples?
"Billy G"
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Randy...
I thought your set-up was way cool.....
Didn't I read that it made an awful racket?
Was the freewheeling/fluid driven prop pitched as the front? If so, did you nre-pitch it when you re-pitched the motor driven piece?
Thanks
325
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I had the privilege to hear and watch and launch Randy's two prop plane at contests. It sounded very different but it felt the same on launch as any other plane.
Ed
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WOW! RANDY!!!!
DO YOU HAVE PHOTOS...THAT WAS A GREAT POST! MODELERS WITH SKILLS LIKE YOURS...BOGGLES MY MIND..(what's left of it! H^^ H^^
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Randy...
I thought your set-up was way cool.....
Didn't I read that it made an awful racket?
Was the freewheeling/fluid driven prop pitched as the front? If so, did you nre-pitch it when you re-pitched the motor driven piece?
Thanks
325
HI Rich
The prop was only freewheeling when the engine stopped and the front prop ceased to turn, At that point the airstream going by at the speed of the plane would turn the prop. When the engine was running it was driven, it even loaded the engine more when the rear prop was on.
The props turned out to be the hard part of the system, Normal props did not work, It took special made props. I don't have time to go into great detail here but this is the basics. The front prop was made from a CF 13 x 6, it was used at 12.5 x 6.25 the rear props were 12.5 x 6.75 , 12.5 x 7 and 12.5 x 7.75. The rear prop always was a little higher pitch than the front.
The 12.5 x 7 turned out to be the one I used and I had a prop one size up and one size down if I ran into problems.
This was not critical , and so long as you had the speeds fairly close it worked great.
At the NATs I wore out a bearing and the rear prop slowed down maybe 1500 to 2000 RPMs, the system still worked well enough to keep all of the good parts I described working. I flew the airplane for 5 or so flights before I changed the bearing that night with ZERO problems, well except maybe it got a little louder.
Props:
Props were the key to this:
Big problem was the rear props had to be special hand made props. I had to carve-laminate these out of wood and cf.
The rear props were nothing at all like a normal prop, these were special made (me carving them) concave (underchambered) on the front of the blades, this system had the rear blade very close to the front one. when coupled the concave front caught much more air from the front and channeled it out wards towards the tips instead of the air just moving over and around the blade.
Of course the were also pusher props, and were composite props laminated with CF mat after carving to shape.
If i did this again I would mold the props from CF as they need to be really stiff.
I would also try a heavier prop running less RPMs instead of the reverse
REgards
Randy
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Thanks, Randy. It is exactly like I remember it from the parking lot at the Holiday Inn Express in Huntersville! The memory isn't completely shot.......... ;D (unless it was the motel parking lot in Jacksonville at the KOI............... !!!!!)
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WOW! RANDY!!!!
DO YOU HAVE PHOTOS...THAT WAS A GREAT POST! MODELERS WITH SKILLS LIKE YOURS...BOGGLES MY MIND..(what's left of it! H^^ H^^
HI Shultzie
I do have photos, however their are videos of the plane flying many times that week. Windy made the videos and had them on his NATs tapes for that year. .... ;D He loved the noise it made.....
Regards
Randy
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You guys are gonna love this, I don't have the "Wyvern' plans, but I do have the "Stuka" plans. How you like them apples?
"Billy G"
Billy?? are you gonna share?
;D
Randy
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You ask, you get. Right now they are on their way to Tom McClain to be reverse engineered into the Wyvern plans. As soon as I get them back I will contact you Randy. How's that, OK?
"Billy G" H^^
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Hi Dennis and Larry ;D
The contra (counter?)-rotating prop I referred to was explained to me, by Randy, to be *fluid* (his word) driven, in other words, by air (his explanation). No gears. Or something like that.
I will see if Randy will reply to this. It was all late one night at a contest while several of us were standing outside at the motel.
Randy????? ;D
Bill , I think your right!
If Randy replies, he may be able to shed some light on the gear driven unit Scott Bair Attempted,.
As I was told, the gears failed and Scott allowed as how he probably should have made them from titanium.
This was all heresay to me , but I believe R.S. might have had personal experience or knowledge of said unit. S?P
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Bill,
When I get the plans and have them copied by FedEx Kinkos, I will send them on to Randy Smith if you approve. How about it?
Tom McClain
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Randy I believe I have pictures but it will take a lot of looking to find them.
Ed
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Well I found it rather quickly and scanned it. At the top is my Juno then a Magnum and then Randy's Magnum with the two prop setup.It looks like a Magnum but I think Randy used his Stunt Craft airfoil to make the Magnum into a much better plane.This was at Jacksonville around 1989? Maybe the KOI.I have a lot of pictures from that contests.
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Randy, obviously you did it, but when I referred to "driven", I was thinking of being
mechanically driven by the engine, e.g. some gears perhaps. I didn't really think in terms
air as the "fluid", which it obviously is. What I'm trying to say is that your description of
how it worked is exactly as I believed it to be earlier.
Yes, I'm frequently wrong, and don't mind admitting it.
But I'm just a tad confused. If indeed, the 2nd prop was freewheeling, and driven by
the airflow from the 1st prop, exactly how does it impart an opposing torque? I can
understanding how its rotating mass can affect precession, perhaps this was its true
value.
My comment about a machinist having "fun" was not meant to be a slight to anyone.
Why, some of my best friends are machinists! Hahah. It does seem to me that most of
the machinists I know have fun with these sorts of things.
Whatever, it certainly was a cool thing, and I wondered if perhaps you should have
sold it as a product.
Best regards,
L.
"The greatest homage to truth is to use it." -- Ralph Waldo Emerson
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Those are 3 absolutely beautiful stunt ships... Wow!