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Figure 6. Deformation – Test Method ITF TB 03/01.
Automated compression machine
The automated compression machine (pictured below) has been developed by the
ITF as an alternative to the Stevens machine for testing tennis ball deformation.
The computer-controlled machine replicates the operation of the Stevens machine,
but provides the following improvements over the Stevens machine:
a. Elimination of operator error in speed and timing of testing.
b. Reduction of backlash (unmeasured movements due to machining tolerance and
wear).
c. Graphical display of useful comparative information such as hysteresis losses.
d. Carousel feed allowing up to 12 balls to be tested in three axes without operator
assistance.
e. The machine can also be used to pre-compress balls according to the Rules of
Tennis.
All of these advantages give the automated machine more functionality, accuracy
and better reproducibility of results than the Stevens machine. For further
information on automated compression machines, contact the ITF Technical
Centre.
