Today we are answering a question often asked by cordless chainsaw users: how tight should the chain be on a chainsaw? This is an important question and every chainsaw user should know how to do it and understand why. Incorrect chain tension can affect the performance of your chainsaw and your own personal safety. The last thing you want is for your chain to be damaged because you were too lazy to check your chain tension (or didn't know how).
Anyway, there's a lot to cover in this article. Plus, there are video instructions in the article so you can see what you need to do to keep your chainsaw at the correct tension. Safety should always be your first priority when using a chainsaw.
How dangerous is it to run a chain under improper tension?
A loose chain will cause the chainsaw to produce an angled cut and it will not cut into the wood on its own, so you have to press down on the guide bar with your own body to force the chainsaw into the cut, which can cause the bar to bend. Another problem with a loose chain: the threat of derailment when spinning around the bar at speeds in excess of 60 feet per second! Getting hit with a whip made of sharp steel blades at this speed can hurt... It hurts. It can even take off a few of your fingers or leave a nasty scar on your face if you're not careful.
On the other hand, the chain of a chainsaw can be quite harmful if there is too much tension. You see, a chainsaw chain is simply a coil of metal that rotates around an oval-shaped guide bar. At very high speeds, rotational inertia and centrifugal forces come into play, and what these forces try to do is turn the oval-shaped loop into a circle. And this results in 2 main stress points on either side of the bar - one behind the drive sprocket and the other in front of the chain (or the bar tip if there is no nose sprocket).
If the chain is pulled too tight, it puts extreme stress on the drive sprocket and the rod tip, which will lead to premature wear. A chain that is too tight also runs the risk of breaking at any time and can erode the guide plate. If the chain is too tight, it can also damage the clutch and bearings when you start the chainsaw.
So how do you make sure you have the right tension for optimum performance and safety? Let's learn these tips together next.
Step 1 :
Place the cooled chainsaw on a work surface (stump, table, etc.) and locate the adjustment screw for the chain tension. Usually the adjustment screw is located in one of two positions - between the guide bar and the inner snap teeth (inside) or between the two guide bar nuts on the side cover (outside).
Step 2 :
You will need to loosen the two bar nuts on the clutch cover. This will allow you to adjust the chain tension pin. If you do not loosen the bar nuts beforehand, you will simply damage the threads on the tension pins and may also damage the bar nuts. Don't unscrew the nuts, just loosen them enough so that you can move the bars up and down by holding the headstock. Before moving on to the next step, disengage the chain brake (and make sure the engine is off!) .
Step 3 :
This is really important - before you start messing around with the adjustment screws, make sure you are holding the rod by the nose. Why do we do this? To make sure the chain doesn't lose tension when you're cutting wood. Think about it, which side of the bar do you use most often when cutting wood? That's right, the bottom side. Each guide bar will rise and rotate around the guide stud as you drive it into the wood. And this upward movement will change the tension of the chain.
To compensate for this inevitable movement of the guide rods (which will happen no matter how tight your guide rod nuts are), what you need to do is to hold the chain tension up by the nose of the guide rod as you adjust it. This way you will ensure that the chain tension remains constant throughout the day.
Step 4 :
Take the end of a screwdriver and turn the adjusting screw to increase or decrease the tension on the chain. When you move the bar outwards and away from the powerhead you increase the tension on the chain. As the bar moves inwards, the chain tension decreases.
Turning the adjustment screw clockwise will increase chain tension and counterclockwise will decrease chain tension. Make a quarter or half turn on the screw. If the chainsaw is brand new and you have just opened the packaging from the box, you may have to turn the screw a few turns to get the right chain tension. For quick adjustments at the job site, a few turns will be sufficient.
Step 5 :
Once the chain is tight enough to the bars that you can't see any light passing between the chain and the bar guides, it's time to test the tension with your fingers. Using your index finger and thumb, give the bottom of the chainring a light tug. It should snap back easily. Do the same in the middle of the chainring. Do not pull around the headstock or clutch cover as the chain will be too tight in these areas.
Step 6 :
Now that the tension has been properly adjusted, it's time to tighten the steel nuts. You must still be holding the rod head up all the way through the previous steps. Using the side of your spanner, tighten the guide bar nut on the clutch cover. Check for play in the guide bar, if your chainsaw is relatively new there should be almost no play.