After a few weeks showing some of the features of Atomic Duck, it’s definitely past time to show some progress.
I’ve been designing and refining this project for a few years now, so I have a pretty good grasp on what I expect each part and assembly to look like; but still, the move from concept design to prototype is always a big one. For example: I spent a whole day defining the rear wheel hanger design because, although I knew what it should look like and how it should work, I still had to translate that into a design that is the right shape, size and geometry to fit with all the others–and that could actually be constructed!
For the move from design idea to real parts, computer aided design (CAD) is invaluable.
The process starts by “blocking out” the whole vehicle–drawing out the broad structure all of the main components and fitting them together to get a initial model. As more parts are added, the parts of the model are continually refined until the whole vehicle is complete and any fitting, construction or component strength issues are resolved.
See the images below of the block layout of the Atomic Duck chassis, as it currently looks.
Because this is just the initial block-layout of the chassis, it is quite likely that most of the parts will change somewhat before the design is finished. For instance, the cut-outs in the forward bodywork rib will change to better accommodate the pedal assembly, when those components are attached.
The false-colour view shows each separate component:
Blue - Chassis rails
Yellow - Front axle tube and Rear wheel hanger
Red - Body cross-section ribs
Green - Side triangulation
The sills and front axle are made from aluminium bar stock, although they have yet to be correctly sized: that will happen along with strength testing of the chassis. The other components are cut and folded from 3mm thick aluminium sheet. The total mass for the chassis as shown is a little over 3kg (~7lb).