Since we are getting close to starting construction drawings on our 24′ Aluminum Power Cruiser design, it seems a good time to share our progress. In a previous post we discussed the design brief and intentions for this design and thankfully, since these haven’t changed, I won’t repeat them here.
Designing with aluminum, steel, plywood, or other plate material, with the intention of using a CNC machine to cut the various parts, requires that all surfaces are developable or have no compound curves. Simply put, the parts must be curved in only one direction. For example, you can wrap a piece of paper around your typical coffee mug, but you can not wrap that paper around a basketball. These qualities must be considered as they greatly affect how the hull and superstructure are constructed.
Every designer seems to have their own methods of creating developable surfaces, some use expensive computer programs while others use the century-old method of hand-drawing multi conic projections. I use a combination of both as can be seen in the screen shot from when I was creating the curved hardtop visor.
Whichever method is used, it is important that aesthetics aren’t sacrificed in the attempt to ease construction.
Using our method, a hull was designed that incorporates some bow flare that transitions to tumblehome in her aft sections. Constructed of 6 major plates that have been cut by a computer, the hull will wrap around her frames and can be easily welded together.
As you can see from this comparison, we have successfully remained very close to our original preliminary sketches. A few changes have occurred to improve aesthetics and ergonomics, like the small cabin house added to the fore deck.