Vintage ducted fan (1975)
 

I posted this in the ducted fan forum and it resulted in a total lack of interest. They seem to be more interested in the specs of the latest turbine fuel fitting. I have 3 turbine engines and they are all fine and good, but they fire me up half as much as the first steps that paved the way. Beyond that, I think that the greatest inovations in R/C came in the mid 70' through late 80s. I say that because ducted fans went from tin sheet rotors on 049s in stick and tissue models into Byron Originals with retracts and .90 sizes engines, RC systems went from single channel to 9 channel computer radios. And most importantly, allot of original ideas were tried. Some of them just did not have the right gear available at the time to make them work as imagined (1/2a ducted fan) or the right functionality was available but the gear was just too heavy. However many of the innovations of that era worked great and aren't given their due today. In my opinion the first commercial ducted fan series suitable for R/C was the Kress RK series, the RK40 most of all, and the first viable airframe was the Ziroli HE162. The follow on kits produced by Midwest like the jetster 20 were worthy succesors and great flyers.

I rounded up a HE162 Ziroli produced by Midwest in 1975 to go with my RK40 built by Kress and I am building them now. The original flew well with the heavier gear of the day and a pattern .40 engine. With a modern .45 Df engine and lightweight materials and R/C system you move the weight down a pound or so and the thrust up a pound or so and you go from a nice sport plane like thrust to weight ratio to a solid 1:1 or better ratio. I love vintage R/C and I think the Midwest/Ziroli HE162 is allot like that first Sabre Jet in the Confederate Air Force.

So far I have framed up the fuse, built the majority of the fan unit, and I am beginning to sheet the wing.



http://www.subarubrat.com/PICS/HE162.jpg

http://www.subarubrat.com/misc/he1622.jpg

http://www.subarubrat.com/misc/he1623.jpg

http://www.subarubrat.com/misc/he1621.jpg

RE: Vintage ducted fan (1975)
 

A blast from the past!

I was a kid in the 70's and poured over second hand RC mags from my cousins. We didn't have the means to do much more than the small tissue and rubber band stuff. I very vivedly recall adds for that kit. It looked like something out of star trek back in the day.

Looking forward to watching this one.

Eric

RE: Vintage ducted fan (1975)
 

subarubrat

Looking forward to more detailed posts on building and flying the DF. Keep them coming we love this stuff. Glad to know that there are a few people left that know how to build stuff.

RE: Vintage ducted fan (1975)
 

Wing is sheeted and the fan mounts are in place. I have also run the servo wire.



http://www.subarubrat.com/misc/wingwle.jpg

RE: Vintage ducted fan (1975)
 

I still have one hanging in my garage built by a friend who has long gone under. Found this particular model in a Pawn Shop and realized whoes it was so I picked it up never to be flown as it was missing a scale pod with the RK40 mounted. This was also the first successful fan model I ever built from Nicks original plans with a rip snortin full blown race K/B 40 with straight pipe. On 40 percent nitro it required a new plug every flight and was dead stick most of the time on final. Loud and sounded like a mad 40 size pylon racer from start to finish of flight. The midwest kits were heavy but quite flyable with gear at that time, a remake would be a lot of fun. Changed out the RK-40 to a Scozzi Fan and flew it until sold several years and a few Violet Scooters (A4s) later. Retired to electric indoors after 26 years of fans and turbines, never looked back but it was a great time. Turbines are ok but they took the fun out of jets at least for me due to overall cost. Still have five or six hanging from ceiling ready to go if bug ever bites again. ed

RE: Vintage ducted fan (1975)
 

Ed, you could repower Wanda with a small fan and turn her into a blowfish.:D

Ross

RE: Vintage ducted fan (1975)
 

I just finished skinning the fan unit with the 1/64th ply and got the wingtips glued on and cut to shape. I have also been pushing hard to get my 1/2a design contest entry done so I am progressing slowly on this one. And of course this week I am working the next 4 days so nothing will get done.

I was just thinking how odd it is that R/C ducted fan has reached the classic/vintage era. When I was a kid in the late 70's and early 80's I saw Mustangs and Coursairs fly at OshKosh and other shows (of course they really flew them hard back them and now they baby them around). The early jets now are just as old or older than the WWII warbirds were then. The same is true of models, the early R/C DF planes are now 30 years old and in that catagory.

RE: Vintage ducted fan (1975)
 

http://www.subarubrat.com/misc/he1625.jpg

http://www.subarubrat.com/misc/he1626.jpg

RE: Vintage ducted fan (1975)
 

Lookin' great!

RE: Vintage ducted fan (1975)
 

After all these years in the hobby nothing makes me groan more than the three little words, "sand to shape". I hate taking at a big solid block of balsa and trying to sand a symetrical form out of it. I am not done yet, but the rough shape is there for the nose and top block and I got some planking done.

http://www.subarubrat.com/misc/he1628.jpg

RE: Vintage ducted fan (1975)
 

Get some life-changing Permagrit tools!
Those Kamdax stands are handy, huh?

RE: Vintage ducted fan (1975)
 

Those "Jet-Guys" If you don't have a $5K turbine, and drive a new Boxter, they won't give the time of day to us "financially challenged"... but, being an old Codger, and still extremely high-winded:eek:, I just couldn't let you gloss-over all the improvements that made the 70's & 80's such a banner hit for you. Yes, they started as bent aluminum impellers that when stressed would literally "fly off the handle" at You, but by '58 the prim & proper English were getting a well-engineered handle on the DF situation. By '59 they were producing very nice nylon propellors for the English diesels and putting them in some very nice and rather scale looking Df F/F models. True,.. You had to wait till the late 70's for radio equipment to just begin to fit something that small... but the DF technology was there and blooming. I have a lot of the old DF plans and there were some VERY nice ones! Not stick & tissue, but well designed aircraft models. I think the oldest one I have is a VERY scale Grummen Cougar from M.A,N. plans dated 1957. Yeah, it was a D.I.Y. bent aluminum impeller, mounted on the "then-new" Thermal Hopper Cox... but the plane is a work of engineering art. Veron had some nice delta models even (they were like the English version of Berkley) I have Nick's Salamander plans... I think they were done before the kit. If You have a mishap (heaven forbid) the plans have a built up wing. so You can replace the wing without a foam core. I reduced it for small micro EDF, but always keep the origional safe. Since I'm a compulsive Postoholic, and have no life, I'm posting a few photos to show what I mean. Your Salamander looks Great!..Can't wait for some in-flight photos!:D Ok,.. I'm done cluttering up your thread, I just can't help myself sometimes:eek:;)
Don't tell me about "sand & shape"... I just got done making canopy plugs for a TopFlite Top Dawg & Roarin'20....My hands are STILL numb... [:o] Bob

RE: Vintage ducted fan (1975)
 

Funny you should mention the Boxster, we are finally about to say farewell to ours after a few years of use. The wife bought it

because it was "cute" and "spiffy" that is her criteria. One thing I have found is that there is often a certain unwarranted

sense of self importance and a lack of appreciation for anything "less" in certain people. And when those people gather in groups

and reassure each other of their status it often becomes unbearable. Car groups are a great example. I cannot attend Porsche or

Lambo owners groups because there is such a lack of honesty and a tension of ego. The Subaru groups on the other hand are so much

more social and relaxed. To sum it up the Subaru attitude is that our STI out performs most Porsches but there are a few over

$100k that are better performers and that is a nice position to be in. The Porsche attitude is that it's a Porsche so it's

better, period. The turbine revolution has exacerbated that problem in model aircraft. I have a turbines myself, they are an

absolute marvel no doubt, but that doesn't mean that the ducted fans are dead and that at 1/8th the price that they aren't great

performers for the money. They were great fun and very flyable 5 years ago before turbines became widely available and they didn't loose that just because turbines exist. There also seems to be no appreciation for revolutionary steps in the path that lead to the turbine being available. I did oversimplify the history of DF prior to the Ziroli/Kress era (wasn't trying to write a retrospective) but there is no denying that kit brought practical DF R/C to the hobby.

RE: Vintage ducted fan (1975)
 

The Boxter was a no-brainer... turbines & boxters go together.:D And you're right... the 70's & 80's were the golden years for D/F development... I just had to say something about the "Pioneer Era". If you are flying turbines, You probably won't need it, but in case you bend the kit I have the pre-kit plans if you ever need to replace anything:D Bob

RE: Vintage ducted fan (1975)
 

As I built it I traced and copied all the bulheads and sheets and the crutch. Also saved the saddles and such just in case. As I said about the Boxster, that is the wife's car, it is one of those cars like the Miata or new Beatle, a chick car. That car has nothing to do with my hobby preferences. My choice is the STI or when I don't have to stop anywhere, the Diablo. People either assume that the car is public domain and crawl on it or do their best to smack it with their car door because their mad at the world. But back to the jets. I don't plan on buying any more turbines for a while, I think they are way overpriced for what they are and are selling mainly to early adopters. I just couldn't resist such a technical marvel. Let's face it though, these turbines out now are the 2nd generation and once they hit MASS production (IE the Chinese start knocking them out) we will see sub $1000 turbines before too long. Look at the Mini helis, the Ikarus Piccolo was very overpriced and once you added in the board, it was $600 plus. Now you can buy better flying helis for around $100. It sold because of the novelty factor. Turbines will probably follow the same pattern and when they hit under $1000 I will probably take more interest in them.

RE: Vintage ducted fan (1975)
 

I have a Chinese turbine, it does indeed run, yes, you are going to see prices drop soon...
The Boxter is the Porsche with panties, my friend has one, we never stop making fun of him! And he always needs a ride to the field, as he can't even fit a 1/2a plane inside...

Ol' P.E. Norman, who did those Veron DF kits, flew RC DF all the way back then, too. Single channel!

RE: Vintage ducted fan (1975)
 

Actually it was Phil Smith who designed the Veron range of ducted fan free flight kits.
He designed a whole bunch of models for Veron, and can still supply copies of most of them, at very modest prices:

Phil Smith
32 Verwood Crescent
Southbourne
Bournemouth
Dorset BH6 4JE
United Kingdom

There is a wonderful overview of some of the early British efforts to produce flying jet models at this site:
http://jetex.org/archive/jetxfiles/200312.shtml

Tomas H.


Terrific web site, well worth a book mark!

RE: Vintage ducted fan (1975)
 

Right you are about Smith versus Norman, but I do beleive it WAS Norman who flew RC DF back then...

Isin't that a great site?

RE: Vintage ducted fan (1975)
 

Yes I´m sure you´re right, P E Norman was one of the famous pioneers of DF.
His designs were sturdy, heavy, high-powered, and fast, probably not well suited for kitting at the time.

RE: Vintage ducted fan (1975)
 

subarurat:

I have to take exception to your generalization of turbine modelers. Your generalizations are so typical of Internet chatter with little basis in fact. Before I ever got into jets, I started asking questions and almost without exception I found jet modelers to be very open and willing to answer questions and talk about jets. I’m curious, have you ever gone to a jet meet and talk to any of the pilots? Where they rude or standoffish? Of course there a few turbine pilots with egos, just like any other facet of the hobby such as IMAC, pattern, scale, etc, but that doesn't mean that all modelers in that part of the hobby are that way.

The other Internet bit of wisdom is Bob Violett is very standoffish and doesn’t talk to anyone other than his close friends. I went to Fla 3 years ago and asked if I could tour his facility; they said fine and gave me the cook’s tour. As I was about to leave, Bob came out and talked jets to me for 20 minutes, answering every question and giving me some suggestions on how to get started. He knew I was there to look and not buy, but he still spent some time with me.

Another Internet theme is only rich guys can afford turbine’s, which is bull. I’m sure there are some modelers who cannot afford one, but the vast majority just doesn’t think it’s worth it. There’s no one on more of a budget than me, but I bought one two years ago. I got the money by not taking a vacation and getting paid instead of taking the time off. I used that money to buy a 2300. So it cost me 3 weeks of extra work that year to buy a turbine. Big deal!

I can’t afford a composite model, so I scratched built a FACET 2300. I got a plan set, foam wing cores and l/g from Kerry (before he offered the semi-kit). Half of the wood was from stuff laying around that we all accumulate, the rest I bought. I’ve got about $300 in the airframe. Of course you have to buy digital servos and such, but you’d have to buy those for any high performance model. I probably have about $3200 in the FACET, $2500 of which is the engine, so you can fly turbines on a budget, if you really want to.

Oh, I drive a 10 year old Sable station wagon, so there goes another Internet gem.

As for the Chinese lowering prices, well, we’ll see. Right now the JJ is a DIY project. If you like to tinker, it’s the engine for you. If you just want to go fly, look elsewhere. I’m not sure the market is much bigger than it is now to cause lower prices based on volume. I’ve never had anyone come up to me and say they’d get into turbines if they were cheaper. They like the technology but aren’t really interested in getting involved, but that’s just my experience, others may have had different comments.
BRG,
Jon

RE: Vintage ducted fan (1975)
 

dont know what this is but i found it in my dads attic when cleaning up...
J.J scozzi inc. .40 ducted fan turb -ax 1

RE: Vintage ducted fan (1975)
 

That's an early Turbax I
I've been looking for something like that...if you're interested in selling it, please PM me...

RE: Vintage ducted fan (1975)
 

If I can figure out how to post pics, I'll post mine. Have an already built 162 with a K&B 7.5 with a Turbax unit. Flies well but it is heavy at around 9 lbs. Just scored a FanJett 50 with a Turbax attached so hopefully it'll get more punch on the go. Mine is rigged with a nose brake tied to down elevator.

RE: Vintage ducted fan (1975)
 

Hi All
Subarubrat you have inspired me and I will get out my Byron F-16 (18 years old) and may be I may finish it and get it going, and fly it.

Cheers

RE: Vintage ducted fan (1975)
 

Stumbled on this thread.
I bought 3 of those fan units, in the box, back in the 70's.
I put two of them in a really huge Avro Arrow, and the third kit I kept as a spare.

The boxes were basically black, with a picture of the red painted engine on front.
I sold the last complete kit that I had 2 years ago at a local swap meet, mint in-the-box.

Just a note: They were not by Kress.

They were by Midwest, with the Midwest logo top right corner.
If memory serves me, I believe there was also the name of a modeller on the assembly instructions.

The product name was actually - Axiflo

There were two sizes, Axiflo RK-20, and the Axiflow RK-40

I believe sometime later, Midwest sold out the Axiflo line to Kress. Kress discontinued the thick card material that was used for the outer shell, replacing it with some type of polycarbonate material.

Kress kept the orignal Midwest Axiflow fan impellers in stock for a long time, and used them with his own polycarbonate outer shell.

The last I recall Kress was also selling out, and Kress-jets.com doesn't even come up anymore.

RE: Vintage ducted fan (1975)
 

Big IS Beautiful... but small is lighter and low inertia survives crashes better! (A MUST, the way I fly!:eek: ) I'm going to do Nicks HE-162 smaller, and with an electric ducted fan. I cobbled in an EFlite 370 brushless motor into a wee Cox EDF.. and it puts out REALLY good @ 11.1Volts. It's also small enough so I can have a scale engine nacelle on it. If it comes out light enough, I might try fitting it with some micro retracts I have.

RE: Vintage ducted fan (1975)
 

Actually, Kress designed the Axiflow for Midwest, so in one sense, they were all Kress fans.

RE: Vintage ducted fan (1975)
 

In my opinion the byron f 16 was the finest flying ducted fan of its day, I spent countless hours improving control surface linkage and came up with some things to do that make it fly rock solid. A very good freind of mine back then could fly one using stunt plane manuevers, one day he had a midair with a giant scale mustang that took off 3/4 of the left wing and still managed to land safely!!!!!! I f there is interest in control surface hookups Ill get into it for you, pm me or just reply on here, I still own mine and also a yellow aircraft A4 skyhawk running os 77s and rossi 81s.

RE: Vintage ducted fan (1975)
 

I think Tom is correct. The RK indicates Robert Kress.


Wm.

RE: Vintage ducted fan (1975)
 

This is great info on ducted fans. As earlier stated, not much on DF activity. But, personally, with the expeirence that is out there on DF and kits in the attic's and plans, Df is still a viable, economically, performance option. I too have been on the JET forum and it is loaded with kerosene, I would like to know out there if there on informational sites on the care and feeding of DF models, resources, meets, etc.
Thanks for any info. Mike

RE: Vintage ducted fan (1975)
 

I believe Kress was one of the main engineers who designed the F-14 and did the model stuff for fun. What I always wanted was the House of Balsa F-86 and a K&B 21. I was a kid when the early ducted fan stuff was out and always watched with intrest, but I was doing good with a UglyStick and a 4 channel Futaba.

RE: Vintage ducted fan (1975)
 

You will have to keep the aircraft as light as possible if you are going to use a kress or axiflow fan, I did a lot of testing of fans in all sizes back in the day and found that they just would not put out the amount of thrust for ther size, The dynamax and byron seemed to be the best for power to weight ratio but the byrofan demanded a larger plane to fit into also needed a cheater hole so that the fan would not colapse the fusealage and also get the volume of air needed for performance. As for the dynamax pulling out every other stator blade helped unload the engine for better air speed and did not hurt vertical performance to much, and the aircraft size could be smaller.

RE: Vintage ducted fan (1975)
 

hey Subaru How far along are you would love to see some more pics!!

RE: Vintage ducted fan (1975)
 

Bob Kress was indeed one of the cheif engineers on the F-14 project for Grumman.

RE: Vintage ducted fan (1975)
 

Ducted planes are a blast to fly! Anyone know what this old girl is? I'll give you a hint It started out with a OS 25 and a kress. NOW IT HAULS A#$ around the field with a K&B 45 RIRE and Turbax.

RE: Vintage ducted fan (1975)
 

Duane Johnson was tremendously active in the mid 70's with fans. Creative and inventive, he designed fans made from cans and blades made of wood. He called his fan the "Jet Pump."

Remember his F-15 Eagle?

I do because I had the kit. Although great, it was a monster. It was too much kit for me at that time. I was lost. I did progress, but got frustrated, and sold it. To this day, I wish I had kept it.

I still have the construction booklet and other literature written by Duane Johnson.

Inspiration.

Thank you Duane Johnson

RE: Vintage ducted fan (1975)
 

I didn't think I still had it kicking around.

Has a tin can ring, and wooden fan.

RE: Vintage ducted fan (1975)
 

Hey Ghost did ever get going on your byron f16? Mine is getting close!!!!!

RE: Vintage ducted fan (1975)
 

f16man, yo can see the full build [link=http://www.rcuniverse.com/forum/m_7787721/anchors_8178780/mpage_13/key_/anchor/tm.htm#8178780]HERE[/link]. Not finished yet but getting there.

Cheers

RE: Vintage ducted fan (1975)
 

i strongly disagree with this statement- having tested and read the papers produced by all of these products.

kress's fan was just as good- in fact better due to the lower rotor blade numbers than the others. any larger fan anywhere near its optimum efficiency is going to yield better returns for energy in. that's inherent in the swept area.

the aspects of a fan- without variable pitch/geometry, is that it is a compromise of efflux and thrust. you cant say one is better because it goes faster- or one can go vertical...its not that simple.

kress was the chief design engineer/program manager for grumman's f14, senior design engineer for the apollo program (lunar lander), and head consultant for grumman's vtol/experimental aircraft program in the 1990s- post retirement.

his work and R&D on fans put them where they are now. Wemotec were born as a result of his findings and studies.

if you can get hold of some of his papers- the math and findings are worth the read and still hold true today.

in summary- his fan- and any fan for that matter...if designed according to his findings (reynolds numbers etc), will be just as good as the next one. you can squeeze out some extra efficiency but it doesnt really matter as you can only optimise a fixed blade for a fixed scenario.

it'll be less efficient at all other speeds.