Composite gear spring

click to enlarge First the flat side molds halves are primed and two plies of carbon fabric is laid up at 45 degrees. The strips are stretched so the fibers actually run at about 30 degrees.
click to enlarge The mold halves are bolted to the board that forms the third side of the mold. The glass rowing from the roll on right is stretched into the channels made from metal studs.
click to enlarge The rowing is wetted out with epoxy resin, the ends are left dry for better handling.
click to enlarge The rowing is twisted slightly into a bundle and placed into the mold.
click to enlarge The mold is full and ready to close.
click to enlarge Another piece of board with some weight is placed in top, that forms he fourth side of the mold.
click to enlarge Rough out of the mold after two day of curing, the last 12 hours at 150 degrees
click to enlarge The ends trimmed and the edges are rounded with a router
click to enlarge The tail spring is all woven cloth, 30 plies of carbon cut at 45 degrees then stretched to about 30 degrees, the middle 15 plies is plain glass cut at 90 degrees.
click to enlarge The mold is all filled up.
click to enlarge Now its closed with the second half and clamped with a pressure, a lot of resin will ooze out as the plies are compressed.
click to enlarge Only a little edge burr cleaning is needed when the tail spring comes out of the mold.

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