Build Log Building a classic - the 1929 Wien

[SoarScale2]

So, I thought I would post some information about a project that I have had in the design stage for several months now. It's been on and off due to many other life commitments but it is now ready for the laser.

The subject is the 1929 Lippisch designed Wien (pronounced veen). This is a 19.1 meter wooden sailplane that boasted some excellent performance enhancements over its predecessor the Professor.

Now, as most of you know, I have this thing about large sailplanes. I like them large because of how they fly. The larger they are the more graceful they fly so this one I am building at 1:2 scale - 9.55m. The root chord is about 30 inches and the wings will be built using my favorite airfoils - Quabecks. One of the other reasons for the scale is that I have a 1:2 scale vintage axel pilot! I’ve had it for years and he simply looks like he needs to be flying – so I’m building a plane for him

At 1:2 scale, weight is a very important factor for me. You’ll perhaps recal my other post regarding low cost, low weight alternatives to ply for sheeting. I’m still researching an alternative that will aid in my weight goal. I have built an aircraft over 55lbs in the past (my 10.6m SB-10) and while it is not too difficult to get it inspected each year for AMA insurance, it can become an irritation. So, while I don't think for one minute that I will achieve this goal, I am shooting for less than 55lb AUW “dry”.

Due to the size and the potential issues of transportation, I am also building this aircraft with transportation in mind. The wings will be in four pieces separated at the root and at the primary break (aileron root). The fuselage will be built in two sections - each about 6.5 feet long. The rudder will stay attached to the aft section of the fuse.

Lastly, the airframe is designed so that I can add a extendable/retractable, self launching capability. This too is designed and I have already started the build process for the custom components required for this. It is not my intent to make this a commercially available item so I will share the details of this as I go along. The high, pylon mounted wing of the Wien makes this propulsion system very feasible because of the space available under the wing. I'll describe the system later in the thread for those that are interested.

The propulsion system has two functions. Where I live today I have no local tow pilots but I do have plenty of asphalt runways. This will allow me to fly the plane without a tow pilot which will be of great personal value. A releasable dolly will aid greatly with this goal and so too is in the build plan.

Also, I am a fan of alpine soaring. Throwing a 9.5m, 1:2 scale vintage sailplane off the top of a mountain certainly makes the adrenalin flow. Having some way to recover from a loss of lift in this flying format is a great benefit!

Anyway, the plane has not yet gone to the laser but hopefully will in the next week or so. As I start the build, I will post here so that you can all verify that I am crazy!! It is very likely to be a slow build also due to other business activities I have on my plate. Here's a few renders of the project so far. Enjoy.

[Asher Carmichael]

OK,
Too cool. This is going to be a good read. Tony, thanks for sharing.
Asher

[Sutton Bank]

You must like a challenge Tony!

Autumn must be "Wien season" - Vince Cockett (UK vintage glider guru) has been researching this very plane....

http://scalesoaring.co.uk/yabb/yabb2...num=1256111666

Vince is going to end up with pretty much the definitive reference on this glider. Funny he never spotted the two retractable electric motors (!)

You may remember Vince's equisite Fafnir from a year or two back, the plans for which he very graciously made free to all as a download.

Rog

[SoarScale2]

Funny he never spotted the two retractable electric motors (!)

lol.......... He's obviously not looking hard enough

Yep, under normal flight you won't even know they are there!! Personal adaptation based on personal needs!!!!!

My problem is I am a diehard engineer and design challenges like this are simply a passion. I can't help it - it's an obsession - we all experience that don't we?

Oh, I forgot to mention. Again, another personal adaptation based on personal needs. I will be adding very discrete spoiler blades into the project for enhanced landing control. At this size, there is a potential for extensive ground effect on landing, I have decided to add blade spoilers into the root section to help with this. Again, hidden away so as to be as unnoticeable as possible.

[Sutton Bank]

Originally Posted by SoarScale2

I can't help it - it's an obsession - we all experience that don't we?

Don't worry, you're amongst fellow sufferers here!

Jumping threads slightly (actually to another of your sailplanes!) did you know that one of the Petrels flew for a while with a pylon mounted motor above the wing roots - so all those guys planning to build your 1/3 scale kit could go tugless, and still be legitimate scale. I think it was a Junkers Jumo starter motor, but I don't know whether that makes it electric or piston.

Rog

[SoarScale2]

Well, this is still in the process of being finished physically, but the design is complete and parts are in process.

The SLS is sort of a hybrid from a couple other designs. A little LET standard SLS arm type and a little Dr. Martin Toma style with pivoting motor and forward folding prop blades. In fact, I purchased the prop adapters and blades directly from Mr Toma in Germany. They are 17" diameter and there are two of them.

I have not yet decided between in or out runner but it is designed with the Neu 19xx series in mind.

The motor and prop pivots at the end of the extension sequence and then pivots immediately when commanded at the begining of the retraction sequence after the motor has stopped. This way, the prop blades are aligned with the SLS arm as they are extended and retracted. This ensures that the prop blades do not strike the wing struts at any time since struts are present on the Wien.

A standard JK type SLS sequencer works fine with the design so no custom electronics are needed except a couple switches. The SLS unit is completely self contained except for the two actuating servos which are mounted in the fuse ahead of the unit.

The fuse doors will be split and "guarded" to minimize airflow into the fuse cavity.

There are no prop alignment issues because the prop is folding (folds via a spring actuated, gear driven system). The positioning of the unit minimizes CG changes also. It does not eliminate the CG changes but they are minimal in this size aircraft.

Here are a few renders of the system from my CAD system as well as a few pics of the SLS arm, the parting tray that will be used to create the mold for the arm and the Toma prop. Enjoy.

Tony

[Hutch]

Ok, well that has to be about the coolest idea I have seen in a long long time! Very nice!

-hutch

[SPasierb]

Tony -- you are my hero. And, a master. This thread is going to be "must see" viewing for me!

[thevirginian]

[quote=SoarScale2;13503549][color=black][font=Verdana]The subject is the 1929 Lippisch designed Wien (pronounced veen). This is a 19.1 meter wooden sailplane that boasted some excellent performance enhancements over its predecessor the Professor.
Excellent project, Tony. How long of a project do you anticipate this one will be? BTW, Wien, or "Vienna" (you pronounced it correctly as "veen") is the capital of Austria.

[SoarScale2]

Hmmmm - how long!! Difficult to say. I do anticipate it to be fairly slow - much slower than many of my other projects. I have the feeling that there might be a west coast to east coast move somewhere in the build process. That will eliminate my workshop from the equation and make it a little more difficult to achieve fast results.

We'll see. Suffice it to say, I will keep the build log going as I make progress albeit rather slowly. Don't be surprised if you see periods of weeks go by without updates. If the move happens, this will definately be the case!!

The SLS will likely go much quicker than the airframe because it is small and much easier to do so I may have that one done well before the Wien.

Tony

[SPasierb]

Originally Posted by SoarScale2

I have the feeling that there might be a west coast to east coast move somewhere in the build process. That will eliminate my workshop from the equation and make it a little more difficult to achieve fast results.

Tony,

I'm here for you! Send your planes to me, I'll store them here on the east coast until you get here. Promise they won't be flown -- often.

Steve

[VincentC]

Well - small world this is. I started researching the Wien about 6 months ago and in my quest for information I made contact with Bernd Diekmann in Germany who was writing a book about the famous pilot of this machine, Robert Kronfeld.

Bernd had accumulated loads of photos and documentation which he generously shared with me so that I could draw a plan for a model, however as time went on it got serious as between myself, Bernd and other very knowledgeable friends in Germany we have put together the definitive history of the glider and the changes made to it over its' short history. I say short, although it could be really long as the gliders whereabouts was known up until 1938 when it was owned by the Frenchman Mons. Lumiere, of the Lumiere brothers responsible for the development of cinematography. After that time it disappeared, believed to have been stored in an attic during the war years to keep it away from the Germans and has never seen the light of day again. So, finding this glider can be likened to the search for the Holy Grail.

I have completed the 3-view and found there were many errors on other published 3 views. I think it is the case of people copying mistakes from previous versions. I have split the 3-view in to parts to make a free plan for others to build a model, although not a proper plan, but sufficient for a reasonably good modeller to work from. I have produced them in 1:3.5, 1:4 and 1:5, but any other size is available - including full size . The fuselage formers are drawn, but it is up to you to add the stringer positions, ribs and construction detail as I am a little busy with the project at the moment. The attached plan to 1:5 is in Greyscale, the original proper 3-view drawings are in colour and will not be released at the moment as they are intended for book publication.

I have other detail reference drawings and am currently working on the changes to the instrumentation

See these old videos from my site

http://www.scalesoaring.co.uk/Movies/Pathe/Movie07.wmv

http://www.scalesoaring.co.uk/Movies...n%20Glider.wmv

http://www.scalesoaring.co.uk/Movies...ex%20Downs.wmv

[VincentC]

Here is the 3 view I drew to give more details for the plan

[philkiteflyer]

Originally Posted by VincentC

Here is the 3 view I drew to give more details for the plan

I started watching this thread not for the glider, but the 'sneaky' launch system. Then you go and share these beautiful drawings which to a draughtsman (Like me ) are pure beauty. I am also a compulsive hoarder so these pdfs have been filed already. Many thanks for your generosity.

I am currently working on a 1950's German designed glider of which I have a personal connection, but it doesn't have the flowing lines or sexy curves of some of the pre-war gliders from Europe, undeniably the center of performance gliding of the time and they looked gorgeous too. . When will this book be published and will it be available worldwide?

Vincent, what do you think the chances are of finding your gliders resting place? I think it may have met the same fate as all the others and been burnt after the war, if it survived the war that is.

Apologies to soarscale2 for hijacking his build thread, but I find these gliders fascinating, and their history is . . . well you all know what I mean, you're all reading this forum . Anyway, have you seen this KA4? It has a 'Real' engine in the back seat and two props driven by belts. Thanks for letting me have my little rave, I'm going to have lay down with a model(planes!) magazine to calm myself..
As a draughtsman and a tinkerer I'm interested in your idea so will be following with interest.

Cheers
Phillip C