I cut and fitted the panels which form the sides of the cockpit. The front of the cockpit is curved to match the inner frame, but the panel is just a rectangle which is bent to shape, joining the inner frame at the top to the floor bracket at the bottom. Similarly, the cockpit side panels are just rectangles, which run from the rear inner corner to the start of the curved part at the front.
The inner frame is joined to the outer frame using a 32mm x 32mm T-section extrusion in 3mm (10gauge) aluminium. The plan is to use 10 of these triangles altogether. Each one will need to be welded into place to form part of the space frame. The planing surfaces and deck panels are attached to these T-sections via more M6 button head screws.
I cut the main part of the floor panel from a sheet of 3mm aluminium. The floor panel needed to have its edges bent up all the way round to join onto the side and front planing surfaces. I thought of two ways of bending the edge of the sheet to the planing angle. One was to clamp the sheet between to pieces of steel angle, with just the bit to bend sticking out, then give it a series of good whacks with a rubber mallet until it reached the required angle. The other method was to cut a slot in the end of a scaffold tube and use that to lever the edge. Old Welsh proverb says – "nothing can resist the power of the scaffold tube".
I tried the scaffold tube method along one edge. It worked, but the corner of the bend was a bit badly defined. I tried the rubber mallet technique on the other side. This worked surprisingly well, but it did need some hefty blows, and plenty of ear protection!
The cockpit side panels are joined to the floor via ½" angle section which runs from one rear corner of the floor, along one side, around the front of the cockpit and back along the other side.
The section of the angle around the front of the cockpit floor obviously needed to be curved to match the floor and the inner frame. To curve the angle section I hammered the edge of one side using a steel drift to stretch the metal. This worked well. Hammering the angle at regular intervals gave a nice smooth curve, and the more it was hammered the further it bent.
Fixing the Planing surfaces
The planing surfaces are fixed to the frame via the same strip that is used to support the deck, but this support strip is fitted at an angle so that it makes the right planing angle. This is easy where the frame is straight, but the rear corners and the bow section need the planing surface support strip to be doubly curved – that is bent along the same curve as the frame, and also angled to the same angle as the hull panels. The shape that I’m after is really a thin section from a cone, so at this point I got out the calculator and a paper and pencil and scratched my head. I first bent the strip into the right curve, using the pipe bender as normal, and then with the strip held over a gap between two bits of wood I gave it a few gentle taps with a rubber headed hammer and bent it in the other plane. Once it was pretty close the final shape was achieved by pulling it in to the frame with the M3 screws, drilling and tapping them in one at a time.
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