Winter Project- Graupner Kadett

[Frank v B]

Went to John's Hobbies yesterday and they had this sitting in plain sight waiting for me.  They found it sitting in the basement store room just gathering dust.  It was a partially built model with a single channel receiver and servo.
The tail end of the fuse was broken off, no plans, no other parts, no other information.

Identification: I was sure it was a Graupner model.  One of the formers had the number 32 printed on it.  Graupner always numbers each part in the sequence of use.  Most other manufacturers use "W" for wing parts, "F" for fuselage (as in former F1, F2, etc.).

The radio was an OS Pixie single channel (superegen which means just about any radio signal will trigger the servo) which I got in 1966 when I was in grade 7.

When I Googled "Graupner airplane kits 1960's" it showed the model was the Kadett (.049-.09 diesel power), 46" wingspan.
Googled the plans on Outerzone.

It will be 3 channel, 46" span, electric.  Vintage.  When done, I will just walk into the store and present it to Randy and he can watch it fly at TEMAC. Randy has become a train guy.  That is his specialty in the store.
The first two photos are of the model as received.  The 3rd photo is of an uncovered model from the internet.  The last photo is of the plan off the Outerzone web site.

Frank

[Frank v B]

With the repair to Cadez's Ultimate out of the way, it is time to turn to this project.

Frank

[Frank v B]

Steps-
1) find the plan- Outerzone has most old plans on their website.  Printed off an 8 1/2" x 11" copy.
2) make a full size plan- It was 46" span so took the ratio with the printed plan and scaled everything up by that ratio.  Drew the fuselage by laying it sideways on the sheet of paper and tracing it.
3) find out how much was missing off the back end.  Did the calculation.  The missing/added part is to the right of the yellow pencil.
4) To make the plan for the wing- draw the span, and the chord and fill everything in between these lines.
5) went to my collection of rib patterns and picked one that would fit between the lines.

Start cutting wood and building.

F.

[GuyOReilly]

Steps-
1) find the plan- Outerzone has most old plans on their website.  Printed off an 8 1/2" x 11" copy.
2) make a full size plan- It was 46" span so took the ratio with the printed plan and scaled everything up by that ratio.  Drew the fuselage by laying it sideways on the sheet of paper and tracing it.
3) find out how much was missing off the back end.  Did the calculation.  The missing/added part is to the right of the yellow pencil.
4) To make the plan for the wing- draw the span, and the chord and fill everything in between these lines.
F.

Frank; I can print the plan full scale, it only requires you to assemble multiple 8.5X11 pages. Let me know if you need a set and I will print it for you.
Guy

[msatin]

If you're looking for "full size" printing Rob D, told me about Reprodux.
They're very inexpensive and copied while I waited

[Frank v B]

Guy and Mark,

Thanks for the options.  This plan only took me 30 minutes to draw fully- less time than it takes me to figure out how to get stuff over to you electronically.

Frank
(The flip phone guy )

[Frank v B]

Death by 100 clamps.


- added doublers so I could add the missing 6" to the back.  Clamped the balsa to the rear fuselage.
- added a doubler across the wing saddle to patch and strengthen this area.  Clamped in place.

Note: these clamps are great.  Available at Dollarama.  They are sold as Tomato Clamps. About a dollar's worth in both photos.   I remove the sharp points on the clamps with a hobby knife.

Frank

[Frank v B]

One way to make a battery hatch.  This is in response to Guy's earlier question for his 1/2A Anderson Pylon project.

Step 1- draw the outline of the hatch and cut it carefully.  Mark the forward part of the hatch with an arrow...if the hatch is rectangular.
Step 2- open the hatch and glue balsa cleats underneath three sides of the perimeter.  The fourth side will become the hatch tongue (right side in the photo).
Step 3- make a balsa tongue (right side, friction fit, held in with pins, no glue- note the cross-grain) and a friction fit cross brace (left side).  This cross brace serves two purposes i) stops the hatch from curling when it is covered and, ii) centers the hatch so it will not slip sideways.
Step 4- put three small drops of glue on the tongue and the cross brace and re-install the hatch and let the glue dry.  When dry, remove the hatch and fully glue the brace and tongue in place.

All that remains is to attach a latch to hold the back end down after the covering is finished.

F

[Frank v B]

back end extension (6") finished (left side of knife point) and the bottom sheeting in place.  Still has to be sanded.

F.

[Frank v B]

Built the stabilizer- opted for flat 1/4" stock and will sand an airfoil into it when it dries.  The diagonals are just for effect*.

Cut out the wing ribs.  To make one the correct size I did the simple math:  Chord had to be 5 1/4"- less 1/4" square leading edge, less 3/4" trailing edge.  Each rib had to be 4 1/4" long.
Took an old flat-bottomed rib and trimmed it to size. Adjusted the curvy part to make it look right.   Aerodynamically perfect! See photo

F.

* Diagonals are for torsional rigidity to control twist because it is so long and thin (high aspect ratio).

[Frank v B]

One wing half is drying.

F.

[Frank v B]

- Servos are in...under the new hatch!
- Motor is in.  This is about a 100 watt system (2S max)
- the second wing half is drying (underneath the fuse in the motor photo).  Yes, I built a left and right wing.  Triple checked.

F.

[msatin]

Looking very nice Frank

[Frank v B]

Joined the wing halves.

F.

ps: thanks Mark!

[GuyOReilly]

@Frank v B clamps are on the right side only?!? 
I am puzzled...