I'm starting my summer build project. I hole up in the summer the way most people do in the winter. This summer I'm building not one but three Graupner Cirrus. Don't ask. The kits are very rare now but demand is still high. Luckily there are individuals making parts and pieces that allowed us to put together enough for three planes. By us, I mean, my friend Larry, his friend Terry and myself.
Terry found rib kits in the UK and the original Graupner elevator bellcranks somewhere.
Larry found fiberglass fuselages in Florida.
Terry scored a complete kit that is in excellent condition and copied the plans for me. He is keeping the kit for his collection though. I scored a truckload of balsa at an auction last year so the wood is mostly covered.
The plans I'm working from are for a 1/6th scale version of the Open Class Cirrus which make it a 3 meter wingspan. We also have the building instructions.
The first challenge is to translate all the building notes on the plans. Luckily there are numbers on each note and translation to English in the book.
Next I had to figure out the dimensions of all the various pieces of wood. There is a list of all the parts by number in the building instructions with approximate dimensions but you still have to make some judgments. For instance converting 13/64" to a common size. All the dimensions are oddball sizes.
Once I got that done I realized that the trailing edge stock was not a standard trailing edge that anyone makes. So I scrounged around and found some that could be cut and then thickness sanded to work.
My plane is going to have ailerons and a tow release so it's going to be more complicated and is the one I'll document here. Besides adding ailerons I will decrease the dihedral from 6 deg. to 3 deg. Which is what the full scale plane has I believe. I will also modify the ribs and wing tubes to accept a straight wing rod instead of the bent ones in the original kit.
That's it for now gotta go get some flying in. The first wing panel is well underway and I'll be back with an update shortly.
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