Monday, May 09, 2011

Simple Chainsaw Bar and Chain Maintenance for the Woodturner

While the chainsaw is a valuable tool for the woodturner it is usually used intermittently. Maintenance is necessary as it is for all tools and can be easily accomplished.
It should be noted that chainsaws are extremely dangerous as tools go and should be treated with respect. Instruction in the use of the saw is necessary before using it and safety is the concern of the user. Protective clothing should be worn along with proper face, ear and eye protection. A well maintained saw is a safer saw.
First of all, examine the bar and chain of the saw. The chain should be sharp with all teeth the same size. Sharpening the chain involves two procedures, filing the teeth and filing the depth gauges. The teeth are easiest to file using the recommended size file and a guide that both holds the file and ensures that it cuts to the right depth. Each tooth should be the same length when finished so if one is duller than the rest and requires more filing, file the other teeth to the same length. One tooth longer than the others tends to pull the bar in its own direction and can cause binding. It is a good idea to touch up the teeth at every filling of gasoline or, if the saw is electric, every couple of hours of use. If the saw hits the ground or something other than wood, consider it dull and sharpen the chain. Some sawyers like to have their chains professionally ground at regular intervals and file in between.
The depth gauges are projections in front of the teeth and prevent the teeth from taking too great a cut and possibly catching and kicking the bar back at the user. If they are too high, on the other hand, the teeth are not able to cut to depth and quickly dull from rubbing the wood. Again, a simple jig from your chainsaw supplier allows for easy measuring and ensuring that each depth gauge is filed to the proper height. Depth gauges should be checked every few chain sharpenings.
The bar should be straight, clean and tight to the saw. There are adjustments for proper tension on the chain and it should be set according to your manufacturer's instructions. Too much tension can lead to over heating and ruining both bar and chain while too little tension can cause the chain to catch and kick the saw at the user or to fling the chain off and cause injury. Generally, all that is involved is tensioning a set screw until the chain moves easily on the bar. The bar is held in place with a couple of nuts that need to be checked every filling or at frequent intervals as the vibration of the saw may cause them to loosen.
One of the most obvious things to check and one that is too often not done is to make sure there is plenty of bar oil in the reservoir. This is different from the oil that is mixed with the gasoline and appropriate oils should be used in either case. Bar oil gets flung off by the movement of the chain but helps greatly in keeping the bar cool and in smooth cutting. Most saws are designed to need the reservoir filled with every filling of gasoline. Woodturners tend not to run a saw long enough to run it dry and may forget to fill the bar oil reservoir.
Routine maintenance should become just that, routine. Once the habit is formed, it ceases to be a chore and instead becomes an enjoyable part of the woodturning practice.

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