12 embedded in a body 14 formed of a composite material which may comprise reinforcing fibers in a resin the resin may comprise for example an epoxy or phenolic resin and the fibers may comprise carbon titanium or nylon 66 kevlar u00ae frame 12 is illustrated in fig2 without the surrounding composite material and may be formed for example from aluminum or other rigid material frame 12 includes a central body portion 16 defining a central opening 18 a plurality of bolt holes 19 and a plurality of arms 20 extending from the central body portion 16 which arms terminate in rings or ring members 22 the rings 22 define openings 23 adapted to receive cylindrical inserts 24 which in turn contain a brake piston 26 illustrated in fig3 and 4 and a tension spring 28 that holds piston 26 in a retracted position within cylindrical insert 24 under normal circumstances each of the cylindrical inserts 24 includes at least one opening 29 in a wall thereof to which a hydraulic fluid line 28 is connected many of the cylindrical inserts 24 will include a pair of openings 29 a first for receiving hydraulic fluid and a second for conveying hydraulic fluid and or pressure to adjoining cylindrical inserts 24 for operating the brake pistons 26 mounted therein hydraulic fluid is supplied to the hydraulic fluid lines 28 and brake pistons 26.