The other day I noticed the throat plate on my 10 inch table saw was a bit wobbly, not all of the leveling screws were touching the supports underneath. I was cutting a length of wood that was shorter in length than the throat plate so it became a safety issue and of course also a quality issue. Time for a precision tuneup. I cut large lumber pieces into strip wood down to about an 1/8 inch or so on this saw so I need accuracy from it.
Not all tablesaw throat plates mount and level the way mine does so you will have to figure out the best way to level yours. But it is important to make sure it is flat and very close to level side to side and front to back.
The first thing I do to the throat plate is make sure it is flat. Then I take a file and flatten the ends of the adjusting screws. The ends of machine screws are typically rough with burrs around the outside edge left from the manufacturing process.
Leveling can be done with the use of a straight edge resting on the table top sliding it back and forth to see if it hits but that is a rather clumsy and hit or miss method, you can't really see how close you are to dead level. All you can tell is if you hit an edge. Better than nothing though and that is how I used to do it. Nowadays I use a dial indicator gauge mounted in a holder. This is not expensive, you can get the setup for around $20.00 but you do want to be sure you have an extension for the feeler end of the indicator so it reaches the table. Dial indicators are useful for other kinds of tool setups as well such as working on lathes, seeing drilling or overarm router depth and router bit heights in standard router tables.
http://www.grizzly.com/outlet/Magnetic-Base-Dial-Indicator-Combo-President-s-Special/G9849
I start by leveling each end at the center then check the level at each of the four screws, then back to double check the two ends. When finished all screws should be firmly resting on the support underneath with no rocking. On this big saw I leave the back end of the throat plate about half a thousandths high and the front end about that same amount low. That prevents the wood from potentially catching when I make my cuts.
For precise cuts like dadoes in miniature furniture or for cutting and tiny strip wood pieces or miniature furniture pieces then I use a 4 inch or 2 inch miniature table saw. Be sure you have level throat plates on these smaller saws. It is not a worry with the Preac or Jim Byrnes table saws as they are designed and made level (unless you bend one) but it can be an issue on Proxxon, Micromark and Dremel table saws.
Since I had out the tools I use to calibrate my saws, lathes and such I went ahead and checked to be sure my table saw blade was still square to the miter slot and that the saw fence was also in proper alignment. I am using the same dial indicator type but a different holder that fits into the miter slot. One of these days I need to make a miter slot fixture for my miniature table saws, no one sells that item.
Saw cuts, drilled holes, routed edges are only as good as your hand control for feeding them combined with the quality of your tools but also it also matters how you set tools up and care for them.
