Klemm Kl 31 (oz7896)


Klemm Kl 31 (oz7896) by Allan Schanzle 1989 - plan thumbnail

About this Plan

Klemm Kl 31. Rubber scale model of the 1930s German touring aircraft.

Direct submission to Outerzone.

Update 3/1/2023: Added article, thanks to mescal1, extracted from HPA post at https://www.hippocketaeronautics.com/hpa_plans/details.php?image_id=12969.

Quote: "The Klemm KL 31, by Allan Schanzle.

Here's another of those obscure German aircraft that I found in the books I purchased in Der Vaterland some years ago. As usual, there isn't much information available, but the books noted on the plan each give a photo and one of them the 3-view presented on another page.

Let's start with a quiz. Who knows the country whose national civil aviation registration letters are PP? Walt Mooney knows, because he has designed at least one Peanut model with that identification. Come on, lads, someone must know. Nope, sorry, folks, it's not Panama, Paraguay, Peru, not even Poland. How about Portugal? Sorry, wrong again. Well dadgummit, if it's a Klemm, it was at least designed in Germany, but their letter is 'D'. I'll leave it to youse clowns to figure out. Let's move on to the little information I have about this dude.

From the first reference noted on the plan, I have translated from the German text to give the following description.

Up until 1930, Klemm had built only with wood, but this was the first 4-seater in the Klemm type series which used steel tubing. The KL 31 was the first German 4-seater with an enclosed cabin. The initial engine was the 120 HP Araus 8 A-3, but later on, versions used the 160 HP Siemans Sh 14a. In spite of the relatively small motor performance for a 4-seater, the KL 31 obtained with the Siemans motor a remarkable top speed of 185 km per hour, and a cruising speed of 165 km per hour.

Up to 1935, about 30 aircraft were built of this type, and it was very worthy of being considered a leading design for additional development of 4-seaters.

The model is certainly straight forward in design, and the only thing that gave me heartburn was the canopy (OK, Paul Gaertner, this time I spelled it correctly, so no more lewd cartoons on the subject). Try this procedure. First, glue the laminated former 4 into position. Then cut, crack, and glue the 3 pieces of 3/32 square that connect formers 4 and 5 at the top. You might want to use 1/8 square to give a little more room for the outside curvature. Next, cut two sets of upright and top braces for the cabin structure between formers 4 and 5.

Finally, you can fiddle around like I did to get the front windshield structure from 1/16 x 1/32 balsa. Cut a piece of cellophane to fit one side of the cabin from former 4 to 5, and another to fit the corresponding top portion, but just the right or left side. The top is done in two pieces. Next, cut flat pieces for the front windshield.

The only other thing you might like to try is the use of reed for the exhausts. Claude Powell gave me a few samples a year or so ago, and I finally got around to trying them. Man, that stuff is something else. Soak it in hot water for a few minutes, and you can bend it, without cracking, around a 1/16 inch radius curve - really. That stuff is made of air, literally. I also tried it for outlines of the tail surfaces. Unfortunately, it has practically no bending moment strength, so I had to put in quite a few braces and supports to avoid wrinkles when the tissue was srunk. You should be able to find this stuff at any good craft store.

Now to the flying. First of all, I used my best balsa (4 to 5 pound, throughout) and the model, without rubber, came out at 1.6 ounces. Sure, that's light for a 30 inch span, but it can be done, and the worst part is that I had to add a small piece of clay to the TAIL!

Use a Peck 9 1/2 inch prop and two loops of 5/32 FAI rubber, each strand being 36 inches long. WHAT????, I hear you say, 36 inches long? Yep, braid the sucker and stuff that mother into that nice wide fuselage.

Maximum safe turns is about 2000, and that, along with a little down and right thrust, will get you 75 to 90 sec-onds in dead evening air. Trust me on this. You don't believe it? OK, go ask Tom Schmitt, Bill Ceresa, or any of the other local yokels. Ya say you're from California? Check with Bob Wetherell, who saw the model fly on his recent trip to the Washington area. This hummer is a flying fool."

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Klemm Kl 31 (oz7896) by Allan Schanzle 1989 - model pic

  • (oz7896)
    Klemm Kl 31
    by Allan Schanzle
    from MaxFax
    30in span
    Scale Rubber F/F LowWing Civil
    clean :)
    all formers complete :)
    got article :)
  • Submitted: 21/07/2016
    Filesize: 358KB
    Format: • PDFbitmap
    Credit*: JoeFergusson, Poacher
    Downloads: 1674

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    ScaleType: This (oz7896) is a scale plan. Where possible we link scale plans to Wikipedia, using a text string called ScaleType.

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Klemm Kl 31 (oz7896) by Allan Schanzle 1989 - pic 003.jpg
Klemm Kl 31 (oz7896) by Allan Schanzle 1989 - pic 004.jpg

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