KEENAN MechFiber 250 and
280 Operator’s Manual
24
Revision C01, 04
th
Dec 2019
8.2 Chain tensioning
1. Setting tension on primary chain
Tension is set on the primary chain to remove excess slack, and to prevent sagging or whipping
when under heavy loads. The secondary drive chain is adjusted automatically.
Coarse adjustment of the Primary Chain Tensioner is made by adjusting the top mounting
position of the tensioner spring where it attached to the front panel of the machine. Fine
adjustment is made by turning the adjuster nut on the gearbox retaining bolt (
A
)
— see figure
10.
35 mm
(1.5 inches) deflection from a straight line (
B
) is advised. Do not overtighten, or
damage to the bearings will result. The primary drive chain spring is nominally stretched to
270
–290 mm
coil length.
There is no adjustment required on the secondary drive chain tensioner. The spring is
nominally stretched to
600
–700 mm
coil length.
If either spring becomes overstretched, they should be replaced.
Figure 10: KEENAN 250/280 Chain Tensioning (showing springs fully stretched)
