Quote:
Originally Posted by Koosley
I've always known that closed ducts increases thrust (thanks mythbusters  ) but have never known how proceed in making them. Thanks for the suggestion on how do make that possible. |
Just keep in mind that the same rules of production apply here as do in MythBusters, i.e. there will be foam everywhere wherever you do this. I would recommend getting layers of foamboard and cutting out circles close to the end diameter with a knife, and then shaving off the remaining parts as close as you can. Then glue the layers together as closely lined up as possible (epoxy/gorilla glue works well), let cure, and then take some sandpaper to the inside to get it perfectly smooth. Make sure that the inside diameter is NO MORE than 1/4" off the tip of the blade, and that's REALLY pushing it. Try to get it about 1/8" if possible. This is the easiest way I know how to do it, it'll be really friggin' strong, and it'll look pretty cool. Make sure to put a grating on both the front and the back that fingers cannot penetrate at all and will resist nuts and screws. If it ends up looking dorky, you can always put some LED's inside the foam to light it up into a cool blue (as the foam is already blue).