The aft cockpit will look much better with a large round-over finish to the edges. They will also be a much more pleasant edge to bump up against or climb over.
The 38mm round over bit in a freehand router, is a quick, but exciting way to produce a sufficiently large radius. To achieve the larger radii common in other cats, one would need to expend time and effort to strip plank or kerf, cored material such as Duflex.
A firm smooth laminate edge is required to support the guide wheel. Unfortunately, the large fast blade will pull some of the low density balsa out, close to the surface. However, I am pleased with the size and finish of edge this technique creates, even though a little filler is required here or there.
Below – supervised removal of enough peel ply to subsequently apply reinforcing tapes.
Below – sanding a smooth guide surface.
Below – routing vertical edges.
Below – routing around corners.
Below – too much off-cut material for the extractor.
Below – when the guide edge is too soft.
Below – the finished cuts.
Below – filling the slight damage.
The Scrumble Project 