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- . There are no hydraulic presses today
that are as fast as the fastest mechanical presses. If speed is the sole requirement
and the material feed stroke is relatively short, the mechanical press remains
the best selection.
- . If a limit switch is used to
determine the bottom, the stroke depth is not likely to be controlled much closer
than .020".
Many hydraulic presses can be set to reverse at a preselected pressure, which usually
results in uniform parts.
Generally, if absolute stroke depth accuracy is required, "kiss" blocks must
be provided in the tooling.
However, Greenerd hydraulic presses are now available with an accurate built-in method
of limiting the down stroke. Greenerd's new closed-loop servo-hydraulic system dramatically
improves stroke depth control, guaranteeing consistent, repeatable results. In
many applications, this system eliminates the need for "kiss" blocks.
- . Hydraulic presses
require some external or auxiliary power to feed stock. The feeder must have its own
power, and must be integrated with the press control system.
There is, however, an increasing selection of self-powered feeding systems available-roll feeds,
hitch feeds, and air feeds.
- . Both
mechanical and hydraulic presses experience this problem. But, the hydraulic system of
a hydraulic press must also be isolated from the shock associated with decompression.
If the hydraulic system does not contain an antishock feature, this shock can
affect the lines and fittings.
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