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Excessive chain tension
information can be used as a guide.
A. On larger horsepower saws and saws with slow chain speeds, the depth gage distance may be increased, which will allow the cutter to take a larger chip. The depth gage distance should be decreased on small saws and direct drive saws.
B. When cutting continually in soft woods, the depth gage distance can be increased somewhat.
C. When cutting hard woods, frozen or resin timber, the depth gage distance should be decreased.
When sharpening the cutting edges on the saw chain, the drive link tangs should also be sharpened to keep the guide groove clean, and any burrs on the sides of the drive link tangs should be removed.
CHISEL. Refer to Fig. CM4 for view of chisel type saw chain. To sharpen chisel chain a bevel or round file is used, depending on manufacturer. Hold file at a 10° angle as shown in View B of Fig. CM21. Note top and side plate angles in Fig. CM22. Refer to CHIPPER CHAIN section for depth gage settings.
GULLETS. The gullet is the open area between the depth gage and the side plate. The gullet should be cleaned out with a round file before every fifth sharpening. This will keep the gullet open and allow better chip clearance and more efficient side plate cutting action. Hold file level as shown in Fig. CM23 and at a 20° angle with cutter.
REPAIRS
Saw chain repairs are accomplished
10°
Fig. CM21—Hold file level for chipper chain as shown In View A. File must be held at 10 degrees for chisel chain as shown In View B.
by removingl damaged Links and installing new links which requires disconnecting chain (chain breaking). Use of a chain breaker is the preferred method of removing llchain rivets when disconnecting a chain. When a chain breaker is not available, such as at the work site, file off lithe rivet head and drive out the riven using a sharp punch. A small chisel or screwdriver may be used to spread side links if rivet is not completely cleared.
Rivet spinning tools are available to install rivets when assembling chain links. If a spinner is not available, then a ball peen hammer may be used if special care Is taken. DO NOT strike the rivet heaa too hard. This can cause a fracture in ihe rivet drum. The rivet can be peened over on the outside circumference with light taps of the hammer. The rivet should not have a flat appearance caused by pounding the rivet and making it spread from the center. Rivets that are pounded flat will not have enough strength around the circumference. See Figs. CM24 and CM25.
CHAIN TFflOUBLE DIAGNOSIS
If the chain] is not performing satisfactorily: 1. Remove dhain from bar. 2. Clean wjith solvent to remove pitch and resii 3. Compare I chain with the illustrations and list||shown in accompanying table. 4. Repair as|| indicated.
GUIDE BARS
SOLID NOSE BARS
Guide rails sometimes split from the bar being (inched while the saw is hung up in a it. Splits of two inches long or less c« be repaired by using ordinary welc methods on bars with non-hardened ils. Repairing splits on bars with hardened rails requires
/\c
special equipment for re-hardening the rails.
Small kinks or bends in guide bars can be removed by laying the bar on the large true anvil or other similar work surface and using light hammer blows to bring the bar back into shape. See Fig. CM26. Technique is very similar to straightening other flat metal pieces.
Use a file to funnel the entrance to the guide rail groove of the bar as
Fig. CM23—Before every fifth sharpening, clean out gullets with round file. Hold file level and at 20 degree angle to cutter.
Fig. CM24—Rivets can be Installed using a ball peen If carefully done.
CORRECTLY PEEKED RIVET INCORRECTLY PEENED RIVET
CRACKED DRUM
Top Plate Filing Angle Side Plate Angle 90°. op Plate Cutting Angle 20°. Gradually increase 5°-55°. angle as cutter is filed back.
