Echo CS-420ES Operator's Manual

Also see for CS-310ES: Service data

Echo CS-420ES Operator's Manual Manual pdf 22 page image

22Tension and compression in timber1. Hinge2. Opened3. ClosedA length of timber lying on the ground will be subject to tension and compression, dependingat which points the major support is.When timber is supported at its ends the compression side is at the top and the tension sideis at the bottom.To cut between these support points, make the first cut downwards approximately 1/3rd thetimber diameter.The second cut is made upwards and should meet the first cut.Heavy stress4. 1/3 diameter. To avoid split.5. Weakening cut to finish.When the timber is supported at one end only, make the first cut upwards approximately 1/3rdthe timber diameter.The second cut is made downwards and should meet the first cut.Overbuck6. Down7. Unsupported endUnderbuck8. Up9. WedgeMake angled cut when one section may settle against the other.WARNINGNever use throttle latch for cutting jobs.CAUTIONIf you have misjudged the effects of tension and compression, and cut from the wrongside, the timber will pinch the guide bar and chain, trapping it.Racing the engine with the chain jammed will burn out your clutch.If the chain should become jammed and the saw can not be removed from the cut donot force it out.Stop the saw, force a wedge into the cut to open it up.Never force the saw when it is jammed.Do not force the saw into the cut.A dull chain is unsafe and will cause excessive wear to the cutting attachments.A good way to tell when the chain is dull is when fine saw dust comes out instead ofchips.