Vintage R/C Helicopter - Du-Bro Whirlybird 505
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- เผยแพร่เมื่อ 16 ก.ย. 2024
- Radio Control helicopters had a rough start back in the early 1970's. They were primitive vehicles compared to what's available today and just only had enough controllability to hover or perform slow, forward flight. This heli is an example of the USA's first commercially produced and successful operational model, the Whirlybird 505 designed by Dave Gray and manufactured by Du-Bro, makers of accessories for R/C model airplanes.
There is no gyro connected to the tail rotor as one would normally find on a modern R/C heli, the engine rotates on top of the main rotor and the fuel tank rotates under the engine with no means of observing fuel level. If the engine quits, the heli falls as if a supporting string were cut. Flight time is strictly limited to six minutes for safety reasons.
Thanks go out to Joel Rosenzwieg for shooting this video!
For a number of years prior to 1971, many free-flight helicopters used the torque reaction system to provide power to spin the main rotor blades. Only one R/C heli took advantage of this ultra simple propulsion system and you just watched it fly. When R/C helicopters first were seen by the public in 1970, there were only two successful machines - The Du-Bro Whirlybird 505 and Dieter Schluter's Bell AH1 Cobra. The differences in the designs were staggering and each model had certain advantages.
I was 11 in 1973 and if I would have seen someone flying one of those I would have been so amazed! RC Heli's have come a long way!
I knew R/C helicopters had a primative start BUT not THAT primative!!!!!!I stand before you in complete AWE. Great job!!!!!
What a crazy design! Way cool to see it fly!
This is the only model R/C heli designed with the engine on top of the main rotor. The idea died with this model in 1975 or thereabouts. This was very low cost to manufacture compared to all other heli's but had too many drawbacks to succeed in the quickly advancing world of rotary flight. Thanks for the piloting compliment.
StormyMaxPerry
I like the way you mix the ancient (the Whirlybird 505) with the ultra modern (the 14MZ radio). Modern marvels in technology have worked wonders for this great hobby. The self cooling engine fan (the spinning engine) was ahead of it's time. Lol.
Great Video!!!
Excellent et très vintage , bravo!
That's nuts, never seen a RC heli like that.
I know a lot of modern flyers? Who would be very pleased to fly like this.Instead of just hovering in the same spot week after week.Have we really come that far from the early days of rc helicopters? 3D yawn! Excellent film.
Thank you very much.
total blast from the past,I know this has been out a while,but I love the early technology,it was simple, creative and worked. No it wasnt perfect by any means,but it worked. how many people out there could even come up with an idea like this without electronics? great job at flying it,right up to the landing.
@RC Hobbyist Extreme - Yes! A stable rotor without torque problems. We had the tiny Cox free flight one that was similar and managed to auto-rotate when the fuel ran out.
Cool. Memories... I had one of these back in the day. Never reached that level of proficiency with it, I spent more time fixing it than flying it. Not crashes, just fixing the mechanism... plastic gears on a wooden frame isn't the best solution for accuracy and reliability! I think I had a Kraft "Sport Series" radio in it.
The tail isn't much of an issue with this heli as it isn't suffering from torque reaction as a conventional helicopter does. It's easy to keep it in check. The tough part is staying ahead of the cyclic because it reacts sooooooo slooooow... So we have a quick throttle and tail but super-slow cyclic. Such a wonderful combination :p Did you notice the sarcasm of that last comment?
Wow... !!! My best friend, Great Good... !!! I wish you every day of your development.
Thanks for the compliments. I'm doing my best to both preserve the old heli's and show them in action. In my opinion, the Whirlybird is unchallenged in overall weirdness. The spinning engine and "wah-wah" sound are its trademarks.
Dave Gray was my boss when I worked in the Toolroom at DU-BRO in the mid 90's
This was my first RC heli. I never got it to fly. Kudos to you! I got a Kavan Jet Ranger next. That one flew very well. And then I was off on my RC heli hobby!
We've come a long way!!!!..Thanks for showing us just how far!
amazing the engine still runs rotating like that. Insane and very quirky. I would not have the patients for such an old design - I am amazed you put the time and money in to keep it running.
Wow that's really cool! If my heli was shaking like that these days though, I would not fly until I fixed it. I suppose that's the way this one is supposed to be.
Awesome! That is one crazy main rotor setup!
Yeah I'm rebuilding my Blade 400 right now... it only goes together one way - there's only a few things you could screw up. It's fun to work on stuff that's built that way. And my Trex is even better :)
when I moved house twenty years ago I left a mechanically complete Lark in the attic. I wish I still had it now. Best of luck with your quest.
This certainly brings back some memories...Great job!!! SteveT.
Its a great heli rc , is remember the time, is beatiful , thanks for this video !!
Dude that is fraekin awesome to actually see one fly!!! Thanks for posting that video and take care of that baby.
Now let's see an autorotation!
...just kiddin =)
Very simple - the fuel tank is that chrome container in the lower-center of the rotorhead. A brass tube 1/8" diameter fits through a hole in the tank cover and goes all the way to the bottom of the tank. A flexible rubber hose connects the brass tube to the carburetor fuel nipple. That's all there is to it.
ha! that is so cool. I'd get tired of the sound though. Cool heli.
Dude! My ears! Saw the thread on RR - what a fascinating machine! I can tell you've flown it before. :)
That has got to be one of the strangest sounds I've heard in RC yet :D
Thanks for that! What a clever design, not seen one before.
We had the tiny Cox free flight model in the late '70s, which flew well, but would usually need chasing (and climbing) to recover it. Cox had a clever rotor made cheaply of 4 plastic blades and a bit of bent wire that went into a fairly decent auto-rotation when the fuel ran out. Still have that Cox in the attic somewhere, I hope...
I love the sound of this helicopter!
that was allmighty nice flight
Fantastic video, I had this copter when I was younger and loved it. Never got it to fly
untethered but I loved it anyway. You did a great job, I wish I was you.
Thanks for the video.
The prop provides 90% of the lift and the engine's torque used to spin the prop is absorbed by the main rotor system causing it to spin in the reverse rotation (of the prop). The main rotor blades on the 505 are primarily used for flight steering and not lift, as on all other helicopters.
The Cobra was very "normal" as it used a central transmission with a centrifugal clutch at its input and two output shafts, one to drive the anti-torque tail rotor and the other to spin the main lift rotor. The transmission was sealed and contained an ounce of oil. Transmissions are precise and expensive devices and greatly increase the complexity of the aircraft. The Whirlybird also has a few gears but they only spin the tail rotor and are under far, far less load, hence run dry.
I had one when they first came out. There was still SOME torque to counter due to some drag in the system. Plus, you do need some method to control the tail, after all.
You have a great idea. I'll have to give it some thought so what I explain will be understandable to all. OK, a new addition to my "To Do" list.
Thanks for the info. I'm now 6 years behind my MHW and should grab some back issues soon.
hillarious! that is awsome! trex's great grand papa
I seen this @ 08 IRCHA. Man this thing can pull the crowd in.
LOL!! Flying an RC heli is one thing but trying to imagine what this would sound like in flight literally drove me to making it airworthy. First had it off the ground in 2004, made its debut flight in front of an audience. Maybe I should upload that video too. I had training gear installed as I had no idea how it would handle but removed in on the very next flight. The picture of it and me (with the weird hat) in my RR gallery is of the second-ever flight, 2004, OC's Heli Gathering.
Some good points though were crisp altitude control authority and an easy-to-master tail rotor (yaw) function. The Schluter was the complete opposite in how it handled. Good forward flight speed meant wind wasn't as big an issue but the tail rotor was always moving whenever power was changed, which was all the time if a consistent altitude was desired. The Cobra was also huge and heavy, being 6 feet long and over twice the weight (about 10 pounds) of the Du-bro. Crashing the Cobra really hurt!
Nicely done! Primitive maybe, you had it under control. Great vintage heli stuff.
> Thanks for posting that video and take care of
> that baby.
I'm retiring this particular 505 and will make flyable another one that's a little more 'disposable'. I haven't measured the main rotor speed but I'm guessing it's around 150RPM. Listen to the rate of engine rotation - that will give you a clue. "Autorotation" HA!! XD
That's correct. And there are/were very few opposed twin cylinder engines of this size manufactured. The Northfield Ross Twin being one of them. Could work...
Come to IRCHA 2008 and see many more vintage RC helicopters. C Ya there!
@Mr400fe
Simple really. The mainshaft is hollow and there's a slim pushrod, spring-loaded down (low throttle) that connects to the throttle arm on the carb and at the bottom end, is being pushed by a little bellcrank incorporating a thrust bearing of sorts where it pushes on the rod. The spring isn't very strong so freedom of carburetor arm movement is critical. Works perfectly.
FANTASTIC !
Regulator? If you mean carburettor, it's controlled by a pushrod that passes through the center of the main rotor shaft and is free to spin with the rotor system. The rod is forced down (engine low speed) by a spring. A crank at the base of the rod pushes the rod up (high speed) and opens the throttle. Very simple.
@outbackjack1974
The fuel is in the chrome drum directly under the rotor blades. Without being visible, the fuel level can only be determined by doing test flights close to the ground and timing the flight to the point of engine cuttoff. Only after this time is known and a count down timer programmed can you fly confidently knowing how much is left. This heli drops instantly when out of fuel. No warning, no autorotation.
That's a pretty good looking heli for what it is. Strange concept though! I've been flying since 1988 and never saw one. I DO remember the Cricket which was a fixed pitch main rotor.
If you think this sounds annoying, just imagine three flying at one time! That's the plan for later this year anyway. Hearing protection a must!
I have the remains of a .25 Lark and a complete Lark II (.40 powered). Pretty delicate machines in the plastics department. Sure would love to get the rest of the smaller Lark parts to make it whole.
In principle you're right there is no torque to counter, in practice though there will be some asymmetry between the effects of the two rotors, be it only on the bearing.
Yeah I seriously doubt you could balance that motor in two axes... everything else is probably balanced, but that swinging motor has got to be a problem. It's very impressive though. I like learning about the history of this stuff. Prevents me from repeating the mistakes of the past :)
The difference in price for these two groundbreaking aircraft was also staggering; About $1000US for the Cobra (radio equipment and 10cc engine not included) vs $125US for the Du-Bro 505. Also no engine (6.5cc) or radio gear included. The drawbacks to the Whirlybird were almost worth spending the extra cash on the Schluter as the Du-Bro is very loud (no practical way to add a silencer - can't rotationally balance the rotorhead) and its limited controllability and speed kept it grounded in wind.
What you are hearing is the Doppler Effect from the engine's exhaust advancing and retreating from the camera's microphone with the spinning of the engine on top of the main rotor. The fuel feed is remarkably consistent otherwise this crazy bird would be impossible to control.
Cool sound from from the rotating engine. :-)
Peter
Ôi giống như máy bay thiệt vậy, mình rất thích chúc bạn vui vẻ nhé 🙋🙋🙋♥♥♥📲🔔
"Oh, like a plane, I really like to wish you a good time" Thank you!
Yeah, it's pretty special but too bad it had an "incident" one week ago. If you saw the crash of the Blue Whirlybird at IRCHA then you can imagine a similar crash to this model. Basically it ended up a little too nose-down after a quick turn to stay away from the flight line at the field and I couldn't pull the nose up from a shallow dive. Main blades are shattered and can be replaced easily and that's really all that was hurt. Now I have two of these to repair! :-(
No muffler, the weight of one would throw the head off balance. In the era of this heli, the early 1970's, mufflers weren't mandatory as they are now. If silencing the engine was necessary the design probably wouldn't have ever happened.
Controls are standard four function - Fore-aft cyclic, left-right cyclic, throttle (altitude) and yaw (tail rotor). Any basic four channel R/C system is fine for this heli. Your MT is a much more complicated heli and also has much better handling qualities. The 505 is vague and sluggish in response. Very difficult to fly. But what else can you expect from the first R/C heli made in the USA? Had to start somewhere.
Don't expect to find too much info on the principle of operation, not the fine details anyway. This system of rotory flight was made obsolete within a couple of years of its invention, back in 1970. I fully understand how it all works but there's not enough space here to explain. Good luck.
I dropped my subscription to MHW a few years ago. Do you remember which issue? The wobbles are rather embarrassing as I did have it perfectly smooth once and then it tipped over, knocking the blades out of alignment. I may fix it but more likely replace the entire heli with another, more beat up model. This one is too nice to risk damage so a "beater" 505 needs to step in here. THX!
Thanks! It's almost impossible to have a wider diversity of RC heli tech than this: 2006 14MZ > 1973 Whirlybird 505. Does the 14MZ help let this fly any better? Nope, just safer (PCM etc.) Cooling is great but the "even distribution" of the exhaust oil is a real mess.
I saw one recently in MHW. Love the swoosh of the blades on the spool up. Thank goodness for modern technology lol. It wobbles a lot eh. Very nice though
Yup, fuel tank. Problem is, there's no way to watch the fuel level and when the engine stops the heli drops just like it was cut loose from a string. There's *no* warning!
@soverato3 I think one side is the cylinder and the other side is a counter balance for the spinning engine.
Not sure, but that would make sense.
kool video
Cool. I wonder how they solved the engineering problems with the centrifugal forces and the fuel supply!
I was thinking the same thing.
Easy. there's a single fuel pickup tube along the outer wall of the spinning fuel tank. Centrifugal force throws all the fuel against that wall and the pickup tube is fully immersed in readily available fuel. The engine draws it up to the carb with little effort.
centrifugal pump dude
wah-wah-wah-wah-wah-wah-wah-wah-wah-wah...
What's funny is I've never even tried to fly a Cricket. I have enough of them and parts but hasn't been a priority. Soon...
"That responsive"? What, are you kidding? >:O I need to think 5 sec ahead just to stop it in the same county. Its poor cyclic is what forces me to pick very calm weather for flying. No gyro at all, read my description upper right of this page. THX!
amazing ,thanks for the posting
sweet vid all the same nice to know what the controls were now. and i can belive that it was a pig to fly with no gyro. thank the lord and lady for the Gyro. lol.
That thing is pretty neat. I could only imagine the headache trying to balance it and fly vibration fee. I would be willing to bet that you had plenty of time balancing just to get it to fly that way
No, not really. I did have it perfect a time or two but then a dumb accident would happen and bend something in the rotorhead. I'd then do my best to straighten it by eye and go fly. Making it 'perfect' invited crashes. What can you do?
This tail rotor might well not be anti torque one since torque producer: engine & torque receiver: tiny rotor r both connected to heli via freely rotating thrust bearings
It might as well be for directioning only
s.@ Engineer Ahmed - correct! The tail rotor on our Cox was a dummy - this one might be active for steering purposes? A small electric motor would do that even in the '70s. Anybody know?
Found it, deep in the past - amongst the first posts. Looks like the tail rotor is powered by the main rotor, steered by the RC yaw channel.
Depends on what type of gyro you mean. OK, I'll tell you: There's a weighted flybar on the main rotor that is a gyro for cyclic stability. There's no gyro connected to the tail rotor. Doesn't need one.
this is awsom,,
Amazing!! Look at the antenna on the TX. That was probably big money for that thing at the time.
Antenna? What's with the antenna??
+Leif Vejby it's like 5 feet long. antennas nowadays are only 3 inches long at best.
***** 3". That depends - I am still not flying Ghz but Mhz.
Why, is it for the novelty?
***** No, it is for the trim buttons, they are sliders on those transmitters,which means that I can feel where I have the trim, quite a nice thing not having to look away from the plane when thermalling, and the trim is faster to set, not having to wait for the beep - - beep - - beep - of the trim on newer transmitters.
Thank you for sharing this video! I love looking at the classic helis.
I have one question for you. How is the throttle controlled? I'm assuming through the swash plate somehow. Perhaps similiar to collective input? IE: Swash goes up=more throttle? That's one thing I never really figured out is how the engine got it's throttle control.
Thanks again!
I've intentionally let it run out of fuel really close to the ground while recording the flight on camera and then measured the time-to-failure. The transmitter timer is set for 45sec less so there's some reserve available. Hearing the timer alarm is a problem!
Whirlybird is in MHW March 2007 issue 201 page 36 only a small pic (actually from 1974) No write up on it. It just appears as part of the history feature
what a great vid. i would like to know what level of cyclic, collective , pitch, roll and yaw the operator had, and how many channels on the radio. for comparisons sake i am currently flying a thunder tiger mini titan.
Ah, makes sense, thanx.
Oh, make no mistake about it, I've had this heli "perfectly" smooth to the eye but again, bad luck steps in on that perfect flight and bangs up the machine, wasting my work. Each time it happened I did a quick eyeball straightening and wobble reduction, and many flights continued incident-free - until last weekend. See posting above for more details.
I really doubt you'll make any heli engineering mistakes if you follow the current trends of design. It's only getting better!
I flew a Micromold Lark in 1975.
No gyro and very underpowered but it flew ok.
I remember the articles in the RC magazines and seeing these things in hobbyshops but I never liked the way it looked myself.
boy, talk about the wah-wah's! I'm building a Cricket now, can't wait to have my way-back machine flying. Your 505 flies pretty darn good, I would never have thought they could be that responsive on cyclic and the tail seemed quite locked in (401?)
Thanks. If GG had enough functions available, this heli could still fly. It is so primitive a heli that high precision R/C gear is a waste on it. Radio link reliability is the most important however. I will certainly agree that today's R/C gear is wonderful. What's next? :D
what?! no inverted flight??
nice video
Yeah, I know. The heli tipped over immediately after I spent hours balancing everything and bent the blade support axles. I bent them back by eye and this is the result. Sorry.
hello i dont think is the blades, i think is more of the piston spinning around and the up and down motion from inside the piston created that shaky looks.
That has got to be one of the most annoying sounding things in the world :D Very cool model though, I don't think I have seen anything like it before.
a plane prop? ingenious. : P
how did you connect the engine with the regulator? or there werent things like that in 1970s?
I have the impression the low frequency oscillation in the engine noise seems to be somewhat in synch with the vibrations of the body, could the vibration be influencing the flow rate of the fuel?
Cox toys back in the mid 70s made a small 020pee wee engine on a small helicopter body with balancing weights.
@ Greenback the woo - we had one of those - it was free flight, dummy tail rotor, but was fully stable and would auto-rotate to ground adequately.
You're very much welcome!
wow strange vintage heli !!! that's funny ^_^
You're welcome. Stay tuned, there will be more :D
I thought the noise from modern nitro helicopters was annoying!
She shakes because she's slightly bent. I've given up trying to get perfectly smooth performance because whenever I spend the time to make all systems perfectly balanced, the heli almost immediately has some sort of 'accident' and I'm right back where I started - shaking. So sorry viewers, it's always going to shake and wobble...
Wow thats neat. Have you ever been bitten by the prop??