Petrol Strimmer.Net

Petrol Strimmer

A petrol strimmer is also known as a strimmer, string trimmer, line strimmer, weedeater, weed whipper, garden strimmer or grass trimmer. Basically a petrol strimmer is a powered device that is held in the hand and uses a flexible monofilament line to cut your grass or weeds or other plants. It uses this monofilament line instead of a blade. The whole petrol strimmer unit consists of the cutting head which is at the end of a long shaft which has one or two handles and usually a shoulder strap attached to it. The petrol versions of the strimmer are powered from an internal combustion engine and this engine is located at the opposite end to the cutting head on the shaft. The electrical version of the strimmer tends to have the electric motor in the cutting head.

It was George Ballas from Houston, Texas who first introduced the string trimmer to the world in the early 1970*s. It was when he was sitting in his car whilst taking it through an automatic car wash that he was inspired by the revolving action of the cleaning brushes in this particular car wash. Once he got home he found himself so heavy duty fishing line and attached it to an empty popcorn can which he then bolted to an edger. He tried it out to some success and from this basic example he developed his string trimmer which he called the weed eater because of it’s effectiveness of chewing up grass and all the weeds in the vicinity.

The petrol strimmer works on the basis that the line in the head of the unit is turned fast enough for it to be held out from the rotating wheel stiffly by the force known as centripetal force. The faster this line is made to spin the stiffer it becomes and hence more efficient as a cutter. Even round section nylon can be used in a strimmer to cut grass and other plants provided that it is powered strongly enough to make it stiff whilst rotating. On some of the more powered petrol strimmer the line itself could well have an extruded shape such as like a star. This helps the line slash materials being cut and because of it’s effectiveness it can easily be used in tougher locations such as woods and forests to cut down large woody plants and small shrubs. At the least if it can’t cut them down it will at least ring bark them very effectively. These lines give you the options of not having to use disks with those tough jobs you encounter.

Design of the petrol strimmer

The petrol strimmer usually has a 21 cc displacement motor as minimum but can range to much bigger engines. The size is very important for the job in hand. The 21 cc engine is capable of turning a 2 mm line with no problems and some of them have nylon blades as accessories to the line reel. When you move up the power range with for example a 32 cc motor then you can easily use a 2.75 mm line and this has often metal blade accessories. The head at the bottom of the shaft has a safety shield on the side of the user for obvious reasons and a rotating hub.

These two parts can be called the head or spool. The petrol strimmer is heavier than it’s counterpart the electrical strimmer. It uses a petrol mix and when in use it can vibrate quite significantly. But on the plus side these units are so much more mobile and are definitely not limited in the power they can output. So if it is a tough job you are facing then the petrol version of the strimmer should be your first choice. In the case of a very large and powerful petrol strimmer you can strap them to your body and suspend them with a harness. These large versions are ideal for such jobs as roadside grass cutters or large over grown areas that need clearing.

The trimmers that use nylon or metal blades tend to have straight drive shafts as they need higher torque to turn the disk as well as having to deal with the shock loads that are transferred back from the blade to the drive shaft and gearbox. The smaller versions of the trimmers can have and usually do have curved drive shafts. This design is perfect for assisting in holding the cutting head at ground level and giving less stress to the person who is operating the unit.

We cannot leave this section without giving you a little info on the alternative to the petrol strimmer which is the electric trimmer. These trimmers are very light to hold and easy to move around. They are quite basic and hence user friendly when it comes to operating them. But the weakness of the electric strimmer is that the length of power cord limits them in use and they are as well a lot less powerful. The maximum diameter of nylon you can use with these units is 2.5 mm because of their maximum output levels. There are also battery operated units out there which are better because you have no power cord to mess around with but batteries run out and need recharging and again the power level of these units are so inferior to that of the power output of the petrol strimmer.

To use

Before starting to use the petrol strimmer the line has to be hand wound onto a reel making sure that both ends of the line are extending from the reel housing. When in operation the motor turns the reel and the line extends horizontally whilst the operator of the unit swings the trimmer in a sweeping motion where the plants have to be trimmed. It is for the user of the unit to decide and control the height in which the cutting takes place and it is possible for him or her to trim right down to ground level if that is what is required. As happens with the petrol trimmer on occasions is that the line will wear out or even break. To deal with this the operator just has to knock the reel on the ground so that the release mechanism allows some of the line in the reel to extend and replace the worn or broken line. So of the more high quality units do have an automatic feed operation that has a small cutter which ensures that the length of line exposed for the cutting is that of the correct length for the cutting process and also to be run correctly by the motor.

The speed and power of the petrol strimmer is controlled by the operator of the unit with a trigger on the handle. A common mistake made by users is to run the unit at full power all of the time. This can cause line breakage or excess wear in the line especially when you have high speed near to objects that must be cut. By running the machine at a slower pace can actually speed up a cutting job as fewer passes are required and of course there are less stops to replace the line. The other benefit of running the machine at a slower speed is that the line will whip around the thinner objects needing cutting without grabbing them.

Most petrol strimmers are powered by 2 stroke engines which feed off gasoline mixed with oil. The pollution laws are having an effect on the petrol strimmer. Four stroke engines are now becoming more popular in machines. Honda manufacturers a four stroke engine trimmer and many other companies such as John Deere now build and supply low emission two stroke engines for the petrol strimmer.