NEWS…VIEWS & TIPS
Your table saw is probably the single most important tool in your workshop. Properly adjusted, it is a joy to use. However, like any piece of machinery, it is composed of a variety of parts which are bolted or screwed together. During use, these bolts or screws can loosen, causing the component parts to move out of proper alignment with each other. Such misalignments can make the saw both unpleasant and downright dangerous to use.
The following discussion deals with tuning up your “contractor’s saw”. This is a saw commonly used by home woodworkers. It is powerful enough to handle most wood sawing needs. while it is portable enough to be conveniently moved around a small shop or to a remote job-site. Some of the tips provided here are also applicable to the smaller bench-top saws and to the larger, heavier, cabinet saws.
Contractors’ saws come in a variety of models and styles. Virtually every major woodworking tool manufacturer has at least one model available. The saw itself is characterised by a motor which hangs off the back of the saw. The blade is driven by one belt. One wheel crank provides blade height adjustment, while a second provides blade tilt adjustment. A mitre gauge, with slots in the table top, allows accurate mitre cuts. A fence can be locked in place on either side of the blade for rip cuts.
Before doing any work with your saw, carefully read, understand and follow the manufacturer’s instructions. This article will give you some general guidelines to enhance your saw’s performance. However, should there be a conflict between these guidelines and the manufacturer’s instructions, the manufacturer’s instructions should take precedence.
Take a few minutes to familiarize yourself with the various parts of the saw. Before starting any adjustments, be sure to unplug the saw. Then collect the tools you will need. Generally, you will need a good 30″ straight-edge, an accurate square, a plastic drafting triangle, and an assortment of wrenches, screwdrivers and allen wrenches. A dial indicator is nice to have, but is not required.
Examine the outside of the saw and its stand and make sure all visible nuts and bolts are tight. Adjust the legs of the stand so the saw sits firmly on the floor.
Lets start with the rotating parts, namely the motor and arbor. Check the bolts holding the motor to its mounting bracket and the bolts holding the bracket to the rear of the saw.
Next step is to check the arbor itself. Remove the blade. Use a dial indicator to check for runout. If you don’t have a dial indicator, you can still perform this check by holding your square firmly on the table top, very close to, but not touching, the flange of the arbor. Rotate the arbor by hand and watch to see if the distance between the end of the square and the arbor flange differs significantly . Ideally, there should be no more than .001 – .003″ of run-out. Any more than that and you should consider replacing the arbor or its bearings.
Lift the motor slightly and remove the drive belt. Use the straight-edge to ensure the pulleys of the motor and arbor are aligned with each other. Place your straight-edge on the arbor pulley such that it touches both the top and bottom of the pulley flange. Then move the motor pulley in or out until both the top and bottom of the pulley touch the straight-edge. (See Figure1). This pulley is usually held in place with an allen screw. Be sure to retighten the allen screw once adjustments are complete. In some cases, it may be necessary to move the motor on its mounting bolts to achieve complete alignment. Retighten the motor bolts.
Inspect the belt for wear and cracks. Most original equipment belts are v-belts. Some are much better quality than others. Consider replacing the original belt with a segmented drive belt (also called link-belt). While much more expensive than a v-belt, this style of belt helps to eliminate vibration, will compensate for slight pulley misalignments and tends to last longer than stock belts.
While you’re underneath the saw, clean out any dust and debris that may have accumulated inside the cabinet. Pay particular attention to the gear teeth. Brush all the stuff off with a stiff brush. Do not grease or oil these gears.