Is it in need of a tune-up?
Why take the time to check a table saw’s as-built accuracy? Is precision when using a table saw essential to you?
Many of these saws will be opened, assembled, and plugged in in the field before being used for construction work. If this is the case with a saw, the quality of the cuts and, more importantly, the operator’s potential safety will be determined by the manufacturer’s as-shipped accuracy. TBB wanted to see how the different saws stacked up right out of the box. So if you have decided to buy a saw best table saw under 500 is best for you.
Blades that are parallel
A saw’s blade must be perfectly parallel to the miter slot to crosscut and rip accurately and safely (s). Furthermore, the fence must be perfectly parallel to the blade.
Whether the miter slot serves as a reference point for both the blade and the fence is essential for table saw alignment and setup.
Alignment of the Blade and the Fence
Work will be forced into or away from the blade if the blade and fence are misaligned. At best, this may result in poor cut quality as the blade and fence taper apart as you progress deeper into the cut. Gouging, burning, and even kickbacks can occur when the alignment closes the gap between the fence and the blade at the end of the cut.
Checking the Alignment of the Blades
Remove the guard and splitter from your blade and replace it with a good blade or a calibration plate to check its alignment. Raise the blade or measurement plate to the top of its travel, then return it to its original position. Any slight blade motions at the top of the vertical travel stop can be prevented by moving downward.
Make use of a dial indicator.
On a reference tooth, mark a reference point on the blade and rotate the mark to the front of the table. TBB took the following measurements with a dial indicator. You can read about and build a homemade jig or fixture to perform the following procedure, but TBB wanted the measurement to be as precise as possible for the H2H test. We used a gauging Dial Indicator with a.0005″ accuracy.
Place the reference tooth in the front of the saw to rest on the dial indicator probe. At this point, the dial indicator should be zeroed out. Now that the dial indicator has reached zero, any blade misalignment that brings the blade’s back end closer to the miter slot will result in a negative reading. Any blade alignment with the back of the saw blade farther away from the miter slot will also read positive.
Rotate the saw’s reference tooth to the back. Move the dial indicator to the back of the saw and place the indicator’s head on the same point on the reference tooth. If the miter slot and blade are perfectly aligned, the reading will be zero.
According to Internet references, a misalignment of more than.007″ should be the threshold at which an alignment is required. The TBB strategy of checking blade alignment with a dial indicator is shown in the illustration below.
Align the blade with the miter slots in a straight line.
The method for aligning the blade depends on the type of saw you have. For information on how to align the blade and miter slots on your saw, consult the owner’s manual. Moving the table surface in connection to the saw trunnion or the trunnion in relation to the table is a common way to make these adjustments. This varies by manufacturer, and the operator must carefully follow the manufacturer’s instructions.
Parallel the Miter Slots with the Fence
TBB used a similar technique to check if the fences on the saws were aligned with the miter slots. TBB took measurements between the miter slot and the fence to determine the parallel condition at two different locations.
The gauging dial indicator was zeroed out after the first reading was taken at the front of the saw. TBB measured the distance by moving the test jig to the back of the saw. If the fence were parallel to the miter slot, the second reading should be zero.
A positive reading indicated that the second dimension was larger or that the back of the fence was not in the miter slot. On the other hand, a negative value indicated that the back of the fence was closer to the miter slot. A negative reading is more concerning because it indicates that a rip cut will pinch the material between the blade and the fence at the end of the cut, potentially resulting in kickback.
Adjusting the Fence
When adjusting the fence, the operator should refer to the owner’s manual for the specific saw. TBB’s fence adjustments were, on the whole, simple and quick to complete.
Now go build something awesome! I hope this helped you improve your table saw accuracy.