Quote:
Originally Posted by WVA
Really interesting presentation of the design progress. And an interesting plane. I'm struck by the likeness of the B-17, at least to me. I am also mystified by the "rollation" process. I watched the video of making a cone, and completely understood that. But how to come up with a fuselage section from a flat drawing is beyond my imagination.
Jim
|
If you've ever built a balsa flying model (like from Guillows) with a rounded fuselage, rollation is easier to understand. Many designs have a large middle former going front to back as the spine, then pairs of cross-section formers that go left to right at given locations along the spine. These typically have square notches cut outside to hold stringers going front to back that form a framework to glue the paper tissue skin.
The easiest way is to build a half fuselage. Then starting from the spine, mark out points where the spine and notches contact your drawing paper while slowly rolling the fuselage. Do this for two adjacent notched formers at a time until all are marked, then join the points on the paper. The more cross section formers and stringer notches there are, the smoother the fuselage parts will be - if the left and right cross-sections are not the same the process has to be repeated.
This process will require a lot of tweaking so don't expect to get a perfect fit the first time, especially if the points are joined with straight lines rather than a smooth curve (like from a french curve template). There are some 3-views that have fuselage cross-sections, and balsa model plans usually include them.
Sometimes there are model plans that include full graphics to print out on covering tissue that sidestep this whole process.