Great Plains 3PYPA Operator Manual - Manual (Page 124)

120 3PYPA Table of Contents Index Great Plains Manufacturing, Inc.
401-647M Table of Contents Index 03/20/2012
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 149.
Chain Slack
Check slack at fixed idlers within the first 8 hours of oper-
ation and tighten idlers as necessary. Check slack at
spring-operated idlers seasonally.
Refer to Figure 148, 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 149 (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).
Meter Drive Chain
Refer to Figure 150 (which depicts planter raised)
When performing periodic lubrication, check chain condi-
tion. Replace chain if any frozen kinks are not corrected
by lubrication.
When performing seasonal checks, lower planter to put
chain at minimum idler spring tension.
Check that idler spring length , measured from outside
of pin to outside of pin, is not shorter than:
7.0in (17.8 cm)
Lift spring off idler assembly . Check that idler assem-
bly pivots freely. Re-attach spring.
Check chain clip orientation. Check chain routing at
shank idler(s)
(see page 153).
Null4:
.eps
50%
Figure 148
Measuring Chain Slack
27264
2
1
1
Null4:
.eps
60%
Figure 149
Chain Clip Orientation
26482
2
Null4:
Figure 150
25AP Meter Drive Chain
29616
5
4
3
3
4
5