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dissimilar metals must be used, consider metal plating to decrease this effect. See the
following web sites for further information:
www.seaguard.co.nz/corrosion.html
www.engineersedge.com/galvanic_capatability.htm
http://corrosion.ksc.nasa.gov/html/galcorr.htm

FATIGUE
Most materials suffer damage when they are bent or otherwise deformed. Even if they
return to the original shape, the damage still exists. With repeated bending, the material
will eventually give way and fail. During the design of the robot, evaluate all the repeated
operations. Make sure none of the materials will be stressed beyond their limits of
fatigue. Consult companies that specialize in bendable materials of the type required.

CORROSION

We’ve already spoken briefly about corrosion in a few places, including Chapter 4.
Materials can be clad in plastic or plated with other metals to decrease the rate of cor-
rosion. If corrosion is a strong possibility, consider using materials that will not cor-
rode. The Kennedy Space Center offers information on the causes and prevention of
corrosion at the following sites:
http://corrosion.ksc.nasa.gov/html/corr_fundamentals.htm
http://corrosion.ksc.nasa.gov/html/publications.htm

LUBRICATION AND DIRT

Moving parts, especially bearings, sometimes require lubrication. Just remember, the
basic function of oil and grease is to smear all over everything!
A buildup of grease and dirt can engender a host of problems.
Electrical problems Lubricants can coat electrical contacts and insulate them
from the mating contact. These sorts of failures are common.
Dirt Lubricants trap dirt, causing extra friction and sluggish action. Eventually,
the dirt swamps out the positive effects of the lubricant. If the robot cannot be
serviced, this becomes a critical problem.

In the design of the robot, try to find sealed bearings and other moving parts that do
not require lubricants. If a lubricant must be used, find an exotic one that is a bit tamer.
Graphite and Teflon are possibilities, but each have their own faults.