We feel that a Logosol sawmill attains the same or better results as with other, small-scale sawing methods. Many a Logosol customer has declared that they have never had such quality timber as that they have sawn themselves. Even so, we do run into customers who want to improve on the accuracy. By now we know that variations in result can have many explanations. What is raw material is very important. Getting good timber from short, large logs is much easier than achieving good accuracy with long, thin logs. Strains created by storage and habitat can cause problems. Certain types of wood cause more problems than others. The time available is also a factor. Sawyers with unlimited time can naturally succeed in getting perfect results more often than those on short deadlines. Demands on accuracy vary. Timber that is quite acceptable for someone sawing wood for rustic docks in the archipelago, will probably not be good enough for someone sawing boards to be used in construction without planing.
Here is information for Swedish Mill owners, to help in adjusting your sawmill to cut the best lumber possible. We have identified several reasons for incorrect measurements when using the Logosol sawmill.
A. Incorrect adjustment or positioning of the sawing bench.
B. Incorrect sawing equipment function.
C. Strains in the timber.
A. Checking the sawing bench
1. Check that all four legs are solidly placed and that the bench does not shift when a heavy log is loaded.
2. Sight along the log support and the cross member to make sure the bench is straight. Do the checks with and without a log in place.
3. Using a right angle, check very carefully to make sure the guide rails lie on the long legs at an exact 90ƒ angle. Even small errors can lead to errors during sawing.
4. Make sure the distance between both log supports and the guide bar is exactly the same and that they are exactly parallel to each other. Use the adjustment block supplied.
5. Check that the guide rail is absolutely straight by sighting along it or by stretching a string along it and using nails or something similar as spacers between the string and the guide rail. Remember that except for the end struts with oval holes, all struts must be loosened before checking straightness. If support legs are used for the guide rail, these must stand on a rigid base, such as a pole driven into the ground. Even factory-new guide bars can easily bend. This is discovered if the guide bar is no longer parallel to the log supports when it is turned over. A bent guide bar can easily be straightened by pressing it upwards or downwards when the saw is fitted to the sawing bench.
6. Check that the guide bar remains parallel to the guide rail by placing a 1.5 m long and straight piece of wood on the guide bar and sighting along it. If the guide bar diverges more than 5 mm forwards or backwards, the sawing result can be affected negatively. The problem with guide bars leaning in relation to the sawing direction is common for non-Stihl chain saws. It is fixed by placing spacers between the sledge plate and the sledge strip.
7. Final check of the sawing bench setting is done by placing a wide plank of maximum length on the log supports for edging. First saw off a XX inch strip from one side of the plank. Then turn the plank over, set the log supports to the same height and saw off YY inches. Now measure the plank thickness carefully. If the plank isn't equally thick along its entire length, either the log supports are incorrectly set or the guide rail isn't straight. It is also possible that the guide rail has been depressed by the plank weight. This happens when heavy sawing equipment is used without placing the legs on a rigid base. If you use a chainsaw the same thing will happen if you extend the guide rail by more than ZZ m without using support legs.
B. Checking the cutting equipment
The saw's guide bar must not be allowed to cut at an angle upwards or downwards. Problems are most obvious when the guide bar leaves the log. If it doesn't 'float' out, but wants to move up or down, it is clear that the cutting has not functioned right. Normally the fault lies with the guide bar or the chain. Reasons for problems with the cutting equipment:
1. A dull chain is the major reason for sawing problems using the Logosol sawmill. If you file the chain while it still is sharp, the time between filings will be longer. A chain that is used until it is dull will soon be dull again.
2. The chain can have been damaged on one side by metal objects in the wood or the like. The chain will still cut, but will pull to one side or the other.
3. The chain is filed wrong. The cutting teeth on one side can be less filed than on the other. The work position while filing can also lead to the teeth being somewhat less sharp on one side of the chain. The chain function is normally not affected by single teeth having problems or if a few teeth are missing after sawing in nails or similar objects.
4. When accuracy diminishes after problem-free sawing the reason is almost always wear on the guide bar. If the guide bar arms are worn lopsidedly, they can be evened up with a grinder, a flat file or a special edge file for guide bars. Once the guide bar arms are so worn that the drive links bottom out in the track, the guide bar must be replaced. Tensions in the wood can sometimes cause symptoms that are similar to those caused by problems with the cutting equipment. The best way to check the cutting equipment is to cut a thin layer from a large log. In exceptional cases the guide bar can lean forwards or backwards because of some error in fitting the chainsaw to the sledge or the guide bar on the electric saw.
C. Internal timber strains
The Logosol sawmill can only make straight cuts. If the timber curves, accuracy is lost. Sometimes strains can cause large measurement variations. Strains are more common in deciduous trees than in coniferous trees. But even there, strains can be bothersome. One example is trees grown in steep slopes. In such cases, a whole lot can be hard to saw. Strains can also be caused during storage. If the bark and outside layer begin to dry, they begin to shrink. Then when you remove one side of the log, the remaining part curves somewhat.
Some tips for avoiding the effects of internal timber strains.
1. Cut logs with internal strains into the shortest lengths possible. If you can reduce the log length to around 2.5 m, the cutting accuracy will be high regardless of large strains.
2. Work the log from all sides successively. One way to reduce problems is to first cut off an outside board from one side, turn the log and cut an outside board and a side board from that side, then take a few cuts from the central part on one side and finish by turning the log and sawing the rest.
3. It's rather easy to discover strains in the log that might cause measurement errors. Each time you pull the saw back, you can read what's happening with the log. As long as the guide bar remains close to the newly sawn surface, there has been no curving. However, when space occurs between the guide bar and the surface or when it is forced upwards, it's time to decide how the next cut should be made to reduce the effects of the strain.
4. No log is without strains. The most frequent cause is that the log's surface tends to shrink, making outside boards bend. This is why it's difficult to saw a board from a large outside piece without having a log in support. This also means that the timber has a tendency to curve downwards at the ends when sawn from above. This is especially true towards the root end where the extra weight of the log end tends to pull the timber down. This is why it is wise to turn the timber once you passed the pith, sawing the rest from the other side.
5. Special arrangements can be needed in order to obtain perfect measurements in the last board sawn from a long log. One effective way is to saw the last cuts with a newly sawn timber as support. Another is to use the special Logosol sawmill accessories to support the timber ends, such as the articulated support or adjustable extensions. If much of the logs that are to be sawn are over 5 m long, it's best to extend the sawmill by half its length in order to get an extra log support.
Call us for accuracy
If as
a Logosol sawmill owner you have tried all the various steps for setting
up the saw bench, for checking the sawing equipment and for adjusting
in relation to possible strains without getting the sawing result you
expect, call us at Logosol. Our broad experience is always available to
help you find a solution to the problem. 
I hope these tips can be useful. Good sawing!
Bengt-Olov Byström
