How Do Chainsaws Work?

How Do Chainsaws Work

The world of logging has never been the same since the invention of a chainsaw. Nearly a century or so ago is when the first chainsaw that resembled the modern ones were put in use. As you will notice, most of them were operated by two men because of their weight and how it was manufactured. Today, however, all popular chainsaws are light enough to be run by one operator and are far more efficient. But have you ever asked yourself how this machine works?

Well, to answer this question, you will first need to know the type of chainsaw you own. Sorting using this criterion is really easy because there are only two types. It can either be a gas or electric chainsaw depending on the power source. Under electric chainsaws, you can have one with an extension cable or a cordless chainsaw. Knowing how a machine works is crucial for its safety and yours as the operator. As such, we have compiled a guide to help understand the ins and outs of your chainsaw.

How Do Chainsaws Work

The Main Parts of a Chainsaw

Like any other device or machine, you will need to know and understand its main parts before going into many details. For a chainsaw, these include an engine, fuel tank, clutch, carburettor gears, guide bar, sprocket, and spark plug. All these parts coordinate with each other to ensure a smooth operation of the chainsaw. You can also categorise these parts into two; the power source and the cutting area.

How Do Chainsaws Work 1

Let us start with the power source. This is what powers the entire machine and helps rotate all the moving parts. As earlier stated, the source can either batteries or gas. In place of an electric motor in electric chainsaws, there is a petrol engine. Apart from this difference, all chainsaws generally work in the same way.

So, how does a chainsaw turn electricity or gasoline to sawdust? Obviously, that is not what literally happens; the chemical energy stored in gasoline or batteries is converted to useful mechanical energy. This is the energy you use to cut down or prune trees. Anyway, enough with scientific language!

If you have a gasoline chainsaw, it most-probably has a two-cycle engine fitted. As such, you will have to mix gasoline with oil when refuelling. Attempting to run the chainsaw without the required type of oil will cause ceasing. This is due to lack of lubrication of the engine’s moving parts. High torque output with relatively lightweight is the main benefit of these engines.

Now that you have the gas tank full, what happens next? Starting the gasoline engine is fairly simple, but you will need to follow the right procedure. First, turn on the ignition switch then pull the starter rope out. When you do the latter, here what’s going on within your chainsaw;

  • The starter rope is set such that when you pull it, the drive cap on the flywheel is engaged. Note that the flywheel has permanent magnets built into it – we will explain the purpose of this later.
  • Consequently, the motion is transferred to the crankshaft, which also rotates as the rope is pulled. This crankshaft is connected to a piston which, as you may guess, will, in turn, react to all these movements. Are we still together?
  • In the process, the piston is forced to move up and down within the cylinder. It is at this point that the ignition process starts. Do you remember the permanent magnets in the flywheel? Well, the purpose of this is to create a magnetic field as it rotates past the ignition coil which strategically positioned along its path. Electricity is induced into the coil, and the voltage travels to the spark plug.
  • The downward movement of the piston within the cylinder opens an intake point of air, oil, and fuel into the cylinder. When it moves back up, a vacuum is created, and the same content is sucked into the crankcase.

However, the fuel in the cylinder is ignited by the sparks from the spark plug hence forcing the piston to move back. The process is repeated within a split second leading to the piston’s continuous movement which is converted to rotary motion by a crank and rod.

The operation of an electric power source is pretty straightforward. Instead of starting the gasoline engine, a motor is supplied with current. The resulting rotation of this motor is what is used by the rod and crank.

The rotary power gained is transmitted by a drive shaft to the centrifugal clutch, which in turn transfers it to the chain. How does the chain receive this power? Well, first it is important to note that the chain is held in position by the sprocket.

This sprocket is connected to a system of gears linked with the clutch. As such, your engine running doesn’t necessarily mean that the chain will also run. This idle position ensures safety and energy preservation. The guide bar, as the name suggests, guides the chain as its sharpened teeth slice through the wood.

Closing Remarks!

The process described in this article is the basic operation of all chainsaws. Depending on the manufacturer, you might find a few varying specs, especially in terms of size. An ordinary chainsaw has a 16-inch cutting bar and a gasoline tank with a capacity of 0.5 litres. Another thing that you might want to keep in mind is the engine’s horsepower. A two-stroke engine usually develops up to 3 horsepower.

Closing Remarks

One last thing… If you try to run your chainsaw and the engine stalls, you might want to check the spark arrestor. Usually, a clogged spark arrestor will prevent the exhaust from exiting the engine. Using the wrong type of oil or too much of it is the main cause of the clog.

Sometimes your engine might not start at all. If that is the case, then the cause could be a defective spark plug or carburettor which you can either clean or replace. Old House Salvage hope that this content was helpful to you. Feel free to leave us a comment below. Happy logging!!

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