How to Shorten a Chain on a Saw
Almost every owner of suburban housing has a chainsaw. And we can’t even talk about the inhabitants of the countryside: such an instrument is a vital necessity for them. And it requires a chainsaw to respect and timely service. All service rules are clearly stated in the instructions.
The saw set should include several chains (minimum 3) plus 2 tires. After 3 hours of operation, it is recommended to turn the tire over. After another 3 hours, the circuit is replaced. Such simple rules can significantly extend the life of all elements of the chainsaw. And in life, we practically do not adhere to recommendations and are guided by our ideas about expediency.
Comparison table of characteristics of chain chainsaws.
After a certain working time of the chainsaw, we simply tighten the chain. And at a certain moment we notice that the tension system does not allow to tighten the chain. The chain has stretched to the limit. You can’t continue working with it, since the extended chain will begin to break the drive sprocket, as a result of which tire wear will increase very much. The chain must be shortened.
Another reason that you have to shorten the chain is to “fit” the longer chain from another chainsaw to your tire. This is also often found, as there is an opinion among users that for “professional” chainsaws, better chains are made.
Chainsaw manufacturers claim that it is impossible to shorten the chain at home, since the technology of their manufacture is very complex and requires high-precision equipment. Practice shows that nothing is impossible. In order to shorten the chain, you will need:
- Electric welding machine (in some cases, you can do without it).
How to remove rivets?
The main parameters of the chainsaw chain.
The chainsaw chain is difficult to disconnect. Rivets are made of high-quality steel and have a geometric shape, which does not allow just to knock out the rivets from the link. The inside of the rivet has a larger radius. At this thickening, the link rotates, and the outer parts of the rivets carry only a connecting function, so it is quite simple to securely fix them on the outside of the chain. The rivet is removed as follows: the chain is fixed in a vice, and the protruding part is grinded. When grinding, we try not to damage the side parts of the links.
Using an angle grinder is not recommended, because the parts heat up very quickly, which will lead to a change in the physical properties of the metal. It is better to use a file or a file for grinding. Stitching is done on both sides of the link. And now the rivets can be knocked out of the chain with a beard, slightly bending the side parts of the links.
Scheme of the tooth chainsaw.
It is also profitable for trading organizations to sell chains in their finished version than small parts for repair. For these reasons, it will be very difficult to find a suitable rivet with the desired geometry. Making it at home will be even harder, so you have to use an old rivet.
As you may have guessed, the chain of the chainsaw will have to be disconnected twice. Do not forget to calculate in this case that the number of guide protrusions on the inside of the chain and the distance between these protrusions are combined with the drive sprocket of the chainsaw. If you shorten the original chain, then this is not necessary. And if this is a chain from another model of a chainsaw, then everything must be measured and calculated very well. Deviation in the chain pitch (even a small one) from the parameters specified by the design will cause the chain to stretch again in the shortest possible time (at best) or break the chainsaw sprocket. The tire will come to an end, as the driven sprocket will quickly overheat.
If all the parameters of the chain are combined with the details of your chainsaw, then you can start linking the links. We connect the links to the rivet, tightly pressing their side parts. It is no longer possible to unfasten the protrusions, since they are stitched flush with the links. Have to use electric welding. The electrode for this must be taken to the smallest diameter.
Determination of chain wear: a. Tooth wear, b. Installation of an additional locking plate on the locking link.
It is not recommended to start welding immediately, as this is a very delicate job. Practice first doing this on other details. So you will at least approximately understand at what current it is necessary to cook and what welding time to choose. And the electrode will become shorter, which will allow for more accurate welding. After all, a very short period of time is enough to “grab” a rivet. After training, we weld the rivets with the side parts of the link. It remains only to file off excess metal on both sides with a file and the chain can be considered ready for use.
Negative consequences of improper circuit repair
The considered option for repairing the chain is not the most reliable, since no one guarantees you the high quality of the final product. The following consequences of such repairs are possible:
File chain sharpening chain chainsaw.
- During welding (especially with a small current), excessive heating of the circuit elements was made, which caused a change in the physical properties of the metal. Soft metal will allow the chain to stretch not along its entire length, but at the weld point. The chain guides will shift, and other elements of the chainsaw (sprocket, tire) will quickly fail.
- Depth of welding more than planned. The inner part of the rivet was welded to one (or several) parts of the link, which became a violation of the mobility of the links. The consequences will be the same as those described in the first case.
- The welding quality is poor. In this case, a circuit breakdown may occur during its operation. The fact is that the circuit undergoes very high lateral loads, so unreliable welding quickly “develops“. The possibility of injury will be very high.
Contact an experienced welder
The question may arise about the advisability of repairing the chainsaw chain, since the consequences of its repair can be so serious. But all this is only due to inept welding. An experienced welder will do this job quickly and efficiently, which will reduce the likelihood of negative consequences to almost zero. And when using rivets without subsequent welding, the previously mentioned moments simply disappear. The only question is where to get such rivets. But to make them is not so difficult if you have a lathe in stock.
How to make the right rivets with an electric drill?
Chainsaw chain structure.
Do not be afraid: nobody offers you to buy a machine. Use an ordinary drill. The entire process of manufacturing rivets using an electric drill and a usual file is described as follows. From a nail whose diameter is equal to the diameter of the inner part of the rivets (we check with a caliper), a workpiece is cut. A piece about 7 cm long. This workpiece is fixed in the head of the electric drill. The drill itself must also be securely locked.
Two files are fixed on a wooden beam, the distance between which will be equal to the width of the inner part of the rivet. It may not work out quickly, but you must achieve absolute accuracy. It remains only to organize a uniform supply of the bar to the workpiece. We recommend using a piece of the board, one end of which is fixed to the fixed part of the workbench using a wide door hinge, and on the second end of the board we fix a bar with files.
Check the perpendicularity of the location of the files and the workpiece. And you can get to work. We turn on the electric drill and slowly lower the files. They will make grooves on the workpiece. Making rivets at one time is not recommended, since it is not worth overheating the metal, but it is necessary to control the thickness of the workpiece on the machined part. A too thin part of the rivet can also hurt you, so you need to achieve maximum accuracy. If you were able to do everything right, all that remains is to cut off the rivet and use it to connect the chain links.
It is better to cut the rivet manually, without using an angle grinder. Do not forget that when cutting metal at high tool speeds, a significant increase in material temperature will occur, which is very undesirable. The finished rivet is in no way inferior to the factory product in quality, so the restored chain will last a long time. Negative moments when using homemade rivets will be practically eliminated. The main thing is that when you install the rivets you do not forget to align the side parts of the links (they had to be unbent when the chain was split). Even a slight protrusion of these elements from the design norm will lead to premature wear of the drive sprocket.
It is recommended to immediately make several rivets as previously described. The point here is not only to stock up on such necessary elements for the future (although this is also important). It is more important from the total number of products to choose the most suitable in size: any deviation from the norm will make the chain vulnerable to high loads.
The use of reconditioned chains is not recommended when working with dense wood.
Why are chains subject to stretching?
This is due to the fact that the oil supply to the driven sprocket is not adjusted. It may happen that the hole for the oil supply is blocked or the adjustment is incorrect. A chainsaw needs periodic maintenance and adjustment.
The chains also stretch due to wear on the drive sprocket. It turns out that on the worn sprocket there is a slip of the guide protrusions. Parts with such friction undergo heating very quickly, hence the reason for chain stretching. In practice, the same thing happens with a low chain tension. The conclusion suggests itself: you need to replace the drive sprocket, chainsaw tires, and adjust all elements. Otherwise, the problem will only worsen: the chainsaw will begin to work jerkily, the chains will continue to stretch, the engine will fail (with a very high probability).
And we also note that when working with a chainsaw, it is necessary to use protective equipment.
This is especially true if you are using a recovery circuit.