When felling a tree, you will need to evaluate the dynamics of the tree but there are also several other important details that must be considered before you choose your trees to fell.

First, look in a 360-degree radius for hazards or property that could be struck by tree that you're falling. If any of these are in reach of the tree, regardless of the direction in which you think the tree will fall, it is highly advised to call in a professional with the proper training and equipment to fell the tree.

Check the weather conditions. If it is a windy day, the top of the tree acts just like a sail and can adversely affect the way the tree will fall in relation to the way you want it to fall. If this is the case, it is advisable that you fell the tree when conditions are more favorable or call in a professional to finish the job.

Look for other trees and shrubbery in the immediate area and how they will be affected when your tree falls.

Also look for snags or loose hanging branches in the tree and surrounding trees. The vibrations and harmonics in the tree created by the cutting action of the chainsaw or the forces caused by windy conditions can be just enough to dislodge the branches where they can fall straight down onto the saw operator. A dangerous hazard that can result in serious injury or even death.

Now that you've chosen the tree you will fell and the surrounding area is suitable for the job, let's look at the fundamentals of felling the tree.

You must first determine the direction the tree will fall. To do so, take into account these basics.

The lean of the tree, which may indicate the direction, the tree will most easily fall.
Also look at the branches of tree and determine if there are a great proportion of limbs or heavier limbs on one side of the tree than the other. This displacement of weight by the limbs can also have a factor on the direction the tree would most naturally fall even if a slight lean of the tree is in the opposite direction. This is a critical choice you have to make and if you are uncertain at all, it is highly advised that you either move to another tree to fell or that you call in a professional to complete the work.

You will also want to take into account other trees or shrubbery in the area. They could affect the tree fall or that it could be damaged by the tree's fall.

Once you have determined the direction which you fall the tree, clean the area around the base of tree so you have an unobstructed zone to work in.

You'll also need to determine paths of retreat for yourself as the tree begins to fall or in case of an emergency. The paths of retreat should be at a 45-degree angle at both sides of the tree opposite of the felling direction. Make certain the entire paths of retreat are clear and unobstructed.

Again, anyone working with you in the area should remain at a distance no close than 2 and half times the length of the tree to be felling and remember never let bystanders or pets in or around the area you are working in. Your partner can be a great help in this regard to make sure no one enters the work zone.

To fell a tree properly, you should also have a set of plastic felling wedges and an ax similar to these. The wedges should be made of a plastic component as not to harm the cutters of the moving chainsaw when used to wedge the tree. Steel or metal wedges will quickly dull a chain and cause a very dangerous condition in the felling process.

Your axe will be used to dislodge any loose bark in the area of your cut as well as the tool you will use to force the wedges into the felling cut.

Also when filing, the filing guide should be held at a 90-degree angle to the bar or level, tilting the filing guide even slightly can result in the misfiled chain that won't function properly. On the top of your filing guide, you'll see lines inscribed into the metal. The lines kept parallel to the guide bar when sharpening each tooth will result in the proper angle required for the tooth's cutting edge when used properly. Your filing guide will help assure a proper and consistent cutting angle and filing depth on each tooth. This is how a properly sharpened cutter should look. Here is a cutter that has been improperly filed and has a severe back slope, a sign possibly indicating that too large a file was used. This chain has a severe hook indicating that too small a round file was used or that the file was pushed down too hard and allowed to drop too far down into the tooth during the filing process. Here you see a top plate with too shallow of an angle and this is a top plate with too severe an angle.

Now that you have the proper filing guide have determined your starting point, begin your filing. Remember to count your strokes, the amount of pressure you are applying to file and do not drag your file back across the cutter. The right and left hand cutters alternate so you will need to file every other tooth from one side of the bar or all of the right hand cutters first for instance. Then change to the other side to sharpen all the left hand cutters again, remembering to keep the angle and depth the same on all teeth.

Once all of your cutters have been sharpened on both sides, you will need to check the depth gauge's height and file down the tang if needed. Place the depth gauge tool on the chain, as shown here, allowing the tooth's depth gauge to protrude in the slot of the tool. If any portion of the depth gauge protrudes above the slot of the tool that portion will need to be filed down level with the depth gauge tool using the flat file. Perform this same procedure for every tooth. If the depth gauges are not maintained and are too high, not allowing enough clearance, this will result in poor performance and result the chain's ability to cut. If you didn't use the proper depth gauge tool and filed the depth gauges too low, below the manufacturers specifications, this will results in a chain that cuts too aggressively, possible causing harm to your saw and increasing the risk of backlash, making the chainsaw very unsafe, which can result in a serious or fatal injury to the operator.

If you have filed your chain's depth gauge several times, you may find the leading edge of the depth gauge will need to be dressed to conform to an angle similar to how it looked when it was new. Stihl depth gauges have a line scribed into the metal showing the proper angle for the leading edge for you to follow. If you don't maintain this angle, it can result in excessive vibrations when cutting as well as diluting the low kickback properties on some chains.

For some people, sharpening a chain is uncomfortable or even intimidating. If this is the case with you, you might want to keep one or more spare chains that are properly sharpened with your while you are working on your chainsaw. As your chain becomes dull, you can easily replace the dull chain with one of your spares.

When you are done with your work, return your dull chain to your authorized dealer where they can be properly sharpened on specially designed on an electric chain grinder and you will be ready to cut again with a set of freshly sharpened chains.

Next, check your chain brake to make sure it is functioning properly and that it engages and disengages. Like an automobile brake, your chainsaw's chain brake will incur wear each time it is engaged. The amount of wear will vary depending on things such as usage or even the conditions in which the saw is used. Excessive wear will reduce the effectiveness of the chain brake and can ultimately render it inoperable.

Begin your own inspection; you should always turn your chainsaw into your authorized dealer to have the chain brake inspected according to the schedule form in your manual. With the engine running at idle, engage the chain brake by moving your left wrist forward while gripping the handle then accelerate the engine to full throttle for no more than about 30 seconds before premature wear to the braking system or harm to the engine. The chainsaw must not rotate. If the chain brake fails to function properly, it's imperative that you take your chainsaw to an authorized dealer for the proper repairs prior to using your chainsaw again.