
31 Dec 2008
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Registered Users
HUBB regular
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Join Date: Mar 2008
Location: Adelaide, South Australia
Posts: 22
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Polypropylene
Could I suggest to first play with a mock up of the screen first, including a dummy of you... or maybe the real you! Just kidding! Then blow fan forced air against fairing and rider shape with a smolke trail to indicate its track. The deflected air should just strike the top of your helmet, Now as for polypropylene ... it's tough, flexible, but without carbon black or other colorant is somewhat UV sensitive... this would not be an issue if you want to peep over the top. As for fabricating it, you could buy it in sheets, or even cut up an existing container, and being a thermo plastic can be heat formed. Your problem will be shaping the convex curve of the shield which will "fight" the concave shape of your "air kick up" top edge. It will be a bit of work but I think the best and most symmentrical way to achieve this will be to construct male and female moulds from construction plywood where there are flat planes. Use polyester car "bog" and ribs at the curved profiles, gussetted to maintain the shapes during the squeezing process. As a high school tech teacher we use ovens for heating thermo plastics... they are about the size of pizza ovens... now there's a thought! Heat the plastic pizza until floppy then wearing gloves, race it to with the drill press and use the chuck to apply the sqeaze to the strengthened top mould, the plastic between the moulds on the drill press table. Wait to cool, remove from the mould, apply a topping of your choice then wash down with a cold  !
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