We’ve been working on a new tailbox design. The Design Intent is to make a tailbox that is a bit shorter than the existing model, but also has some height for bulkier items. We’re going to try something a bit different–these new talboxes will have carbon fiber exterior surfaces with bonded aluminum inner surfaces. The hope is that this will allow for a simpler mold and layup, thus reducing manufacturing costs.
 
The modern way to produce a mold would be to design in CAD software and then have the plug carved by a CNC router. But this process is quite expensive and hard to justify for a small run. So, we opted to do it the old fashion way by carving the plug by hand.
The process involves building a framework out of wood, then laying foam on top. once the basic shape has been carved, autobody filler is used to finalize the shape and produce a hard surface.
 
 
Ideally one would use polyurethane foam, because it is not affected by the solvents in autobody filler, but polyurethane foam is hard to source, so we use the more common insolation styrofoam and a layer of epoxy to protect it from the solvents.
 
 
The grey images show the plugs, which are the positive-shapes that will be used to make the negative-shape of the molds. The vertical surfaces are the flange areas that will be the outside edges of the molds.