Great Plains NP3000A Operator Manual - Manual (Page 130)

126 NP3000 and NP3000A Table of Contents Index Great Plains Manufacturing, Inc.
407-613M Table of Contents Index 2014-04-22
Chain Maintenance
Inspect and lubricate chains regularly. The slack of new
chains tends to increase during the first few hours of
operation due to seating.
See also “Chain Routing” on page 159.
Chain Slack
Check slack at fixed idlers within the first 8 hours of
operation and tighten idlers as necessary. Check slack at
spring-operated idlers seasonally.
Refer to Figure 80, which, for clarity, greatly exaggerates
slack, and omits the idlers.
1.
Measure the span for allowable slack:
Locate the longest span of each chain (usually the
span which does not run through the idlers).
2. Determine the ideal slack:
Long chains (over 36in/91cm):
1 ⁄
4
in per foot
Vertical short chains: 1 ⁄
4
in per foot (2.1cm/m)
Horizontal short chains: 1 ⁄
2
in per foot (4.2cm/m).
3. Measure the current slack :
Acting at a right angle to the chain span at the center
of the span, deflect the chain in both directions. The
slack is the distance of the movement.
4. Adjust the idlers for ideal slack.
Chain Clips
Whenever mounting a chain, make sure the clip at the
removable link is oriented to minimize snags.
Refer to Figure 81 (arrow shows chain direction)
Install clip with open end facing away from direction of
chain travel (shown by gray or striped arrows in chain
routing diagrams).
Figure 80
Measuring Chain Slack
27264
2
1
1
Figure 81
Chain Clip Orientation
26482
2