The table must be level and flat, this can be checked with a level and a straight edge. If you have purchased a used machine and it is not flat you have the option to have the table ground flat, but it could be costly. If purchasing a new machine take a straight edge and check the same way before purchase.
The table must be square to the blade, use an accurate square to check this. If not 90 degrees the table can be adjusted using the
The table insert should be slightly lower at the front and slightly higher at the rear. This can be achieved by carefully filing at the front and using tape to build up the rear. It also should have reasonable clearance around the blade, use thin ply for the insert. It will not damage the blade and they are cheap and easy to replace.
The post has fitted to it the blade guard, the guide bearing and thrust bearing. It travels up and down to allow clearance for the thickness of the wood being cut. This column must travel square to the table. If this does not happen, it can change the gap between the rear of the blade and the thrust bearing and require the guides and thrust bearing to be reset each time the post is moved up and down .
The guard is most important for safety and must not be removed. The top guide assembly has two side guides, which are adjustable laterally and back and forward to accommodate different size blades. The guides are usually metal which create heat and friction and can make contact with the teeth causing damage to an expensive blade.
You can use wooden blocks or cool blocks, which have a dry lubricant. They can be adjusted so that they are right near the blade, which can give better support to the blade and will not increase noise or heat.
On some saws the guides are ball bearing rollers which can be adjusted into light contact with the blade giving much greater beam support. Add more rollers for larger blades or remove for smaller blades. As these run on the curve of the rollers there is much less surface area contacting the blade reducing heat and friction. The noise level is also reduced.
Most saws have bottom guides. Some are fixed to the main frame of the machine but can be adjusted the same way as the top guides. For correct running of the saw, you must adjust the bottom guides. Some guides are fitted on a shaft, which can be removed from the saw. By turning the guide over so the side guide rollers are at the top, closer to the top guide rollers, thus reducing the distance between the rollers, giving increased beam support. Use paper to adjust the side roller clearance with the blade set just behind the gullet of the blade and have about two millimeters between the rear of the blade and the thrust bearing. This set up takes a bit of time and patience and when mastered will give you the best results.
Blade selection can be a subject on its own. You will end up with a range of blades likely ranging from 6 mpm to 25 mpm with 1.5 T.P.I to 12 T.P.I. The larger blades with smaller T.P.I are used for large and deep cutting on dense woods. Smaller blades and more T.P.I are used for fine cutting and curved cutting. When setting up the blade, the top wheel can be adjusted to allow for the blade to center on the wheel for correct travel by cantering the wheel in or out at the top for centering the blade.
When you have done this and adjusted the top and bottom guides we come to tensioning. This is the
most important single factor affecting the saws performance. Use trial and error until to arrive at the tension for each blade that suits you. Some saws have tension scales. These may not be very accurate and can only be used as a guide for work up to 50 mm thick and unless the tension is released after used this can stretch the blade causing the scale to be incorrect by a larger amount. When you have arrived at what you feel is the tension for the best result put a piece of masking tape alongside the tension block at the rear of the top cover. Mark and record which size of the blade.
Using a fine file and being very careful while the machine is running, place the file at the rear of the
blade and lightly file the back of the blade to remove any bad join in the weld. The rear of the
blade should be straight then rock the file so as to take any bad edges off the blade. This will improve
the performance of the blade and run smoother with the thrust bearing.
Most band saws do not cut square to the fence. Some fences are made so they can be adjusted to allow for this lead. To determine the direction of cut for each blade, use a piece of 6 mm MDF
slightly longer than the table width and about 150 mm wide, using a pencil marking gauge, mark a line parallel to the MDF edge. With the machine running cut free hand down the line until about halfway. Stop machine and carefully clamp the MDF back and front to the table.
Bring the fence up to the edge of the MDF and adjust the fence to the MDF. Now clamp the fence to the table. Every time you change a blade you will need to redetermine the lead. Use a bevel
square to record the angle for future use.
Most fences are not square to the table. You can correct this by fixing MDF or plywood fence to the supplied fences. To correct the out of square, use paper, cardboard or sandpaper behind the new fence and fix through the supplied fence with screws. You can make your own fences with two different heights, longer than the table width using the bevel square and clamp to fix to the required width of cut.
written by Paul Koch
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