Gordon Johnson has been using CS tubing to mold superlight carbon propellers. His procedure is explained below (PICS TO FOLLOW SOON): Trim a GWS prop down to smaller size, and sand sharp edges on the hub rounded. Sculpey clay, spruce stick, and the prop. The prop has been pressed in the clay, baked per directions on clay and now supports the prop. Prop and clay are waxed. The Ayrdyn heat shrink is slit lenthwise, waxed on the inside, and clear packing tape stuck on one edge. The CF cloth/tissue layers wetted with epoxy are laid down on the inside of the heat shrink in reverse order. The heat shrink with CF layers is wrapped around the prop and support and taped together on the bottom, and then shrunk tight. After curing at room temperature per epoxy directions, the heat shrink is slit on the back side and pealed off. CF molding still in place is baked at ~120 degrees F per epoxy directions. The molded CF prop is pulled off the original prop and clay support. Front of molding Trimmed and sanded prop. A balsa disk with aluminum hub is glued in the back side to allow a press fit on a 1mm shaft. Original prop with rubber adapter weighs 1.41 gr. The new CF prop weighs 0.34 gr., more than one gram less. Here is the prop mounted on a 22 gr 13-inch Fokker D-VII. The weight savings due to the prop amount to almost 5% of the AUW. More recently he made a 5-inch 3-bladed prop for a 14"-span profile P-40." He also says that: "I have made larger props. My focus has been to make a lighter version of a Wes 16 cm prop. Theirs weighs 1.4 gr, and mine weighs 0.35g. But, mine has just barely enough stiffness for a 9 gr indoor plane. I'll make larger ones if needed, but I have to convince myself it makes sense first. I'd probably do a 9" WES prop next, but for a 4mm pager motor the gear ratio would be huge (like 45:1, which I have), but I just think it would be counterproductive. I probably won't go there till I have my wind tunnel fully fuctional and callibrated."

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