User manual

Table Of Contents
The drive motor assembly is suspended from the frame in a bracket. The pivoting
bracket has two rotational degrees of freedom and allows the drive wheel to pass over small
obstructions on the mooring cable. The drive wheel is pulled against the cable by a spring.
Frictional coupling to the cable is sufficient to propel the MMP against a static load of several
pounds (several thousand grams). The actual load limit depends on local environmental
conditions and can be variable.
IMPORTANT
Mooring cable tension less than 500 lbs allows the spring to shorten. The shorter spring reduces
frictional coupling between the drive wheel and mooring cable, reducing the MMP lift capacity.
Other Components of the Drive Train
Guide wheels for the cable are located next to each of the cable retainers. The wheels are
machined from an internally lubricated thermoplastic polyester, which is dimensionally stable,
provides strong resistance to wear, and has a low coefficient of friction. The guide wheels rotate
freely on bearing races with Torlon plastic balls, which have high compressive strength and low
rolling friction.
The mooring cable itself is a standard marine cable with a steel core and a polyethylene
jacket. The diameter of the steel wire can range from 3/16” (4.76 mm) to 5/16” (7.94 mm). The
corresponding outside diameter of the jacketed cable then ranges from 1/4” (6.35 mm) to 3/8”
(9.53 mm). Smaller cables cannot support the 500 lbs minimum mooring tension that the MMP
requires. Larger cables will not fit in the contoured drive surface of the drive wheel, significantly
reducing the MMP lift capacity.
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