Stanley DS12 User Manual page 13

WHEN TO TENSION
All chains have a tendency to stretch when used. Diamond chains
stretch more than wood cutting chains because of the abrasive materials
they are cutting. When a chain stretches to a point where the drive links
are hanging approximately 1/2 in-3/4 in (12-18 mm) below the bar, it's
time to tension the chain.
HOW TO TENSION
To tension the chain, fi rst loosen the side cover nuts, then while holding
the nose of the bar up, use a screw driver to turn the tensioning screw
clockwise until the chain drive links hanging below the bar are just begin-
ning to enter the bar groove. Continue to hold up on the nose of the bar
and fi rmly tighten the side cover nuts, (20 ft-lbs, 27 Nm). And remember,
it's the side cover nuts that hold the bar in position.
NOTE: MAKE SURE THE BAR ATTACHING NUTS ARE FULLY
TIGHTENED AND THE CHAIN GUARD IS IN PLACE.
HOW TO PREVENT CHAIN TENSIONER
BREAKAGE
Do not attempt to adjust the tensioner without fi rst loosening the side
cover nuts. Do not use the saw without making sure the side cover nuts
are tight. If the side cover nuts are not tight, the bar can slip backwards
during cutting and break the tensioner pin.
OPERATION
ADDITIONAL INFORMATION
Utility chainsaws operate with looser chain tension than wood chain-
saws. It is common, on the utility chainsaw to have the drive links hang
completely out of the bar. Wood cutting chainsaws use oil to lubricate
the chain. The oil makes the chain very slippery and allows the drive
links to fully nest between the teeth of the drive sprocket. The utility
cutting chainsaws require water for cooling and fl ushing the cut. Water is
not as good as oil as a lubricant. Also, there are cutting particles mixed
in with the water. As a result, sometimes the drive links do not nest
properly on the drive sprocket. When this happens, the chain acts like it
got tighter. There seems to be "tight" spots and "loose" spots as you pull
the chain around the bar. If you tension when the chain is in one of the
loose spots, it will be too tight at some point in it's rotation around the
bar. Rotating the chain completely around the bar by hand will let you
know you have the chain properly tensioned.
ADDITIONAL TENSIONING TIPS
1. To reduce chain stretch and tensioning downtime, use 20 PSI (1.5
bar) or greater water pressure.
2. Oil the chain at the end of the day to prevent rust but be careful not to
over tension in this condition.
3. When pulling the chain around the bar by hand, be careful not to
touch the bar with thumb or forefi nger. The bar rails can be very
sharp. Using leather gloves grab only the diamond segments to pull
the chain.
4. Always turn the hydraulic power source off before tensioning the
chain.
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