What Is Runout on a Table Saw Arbor?

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Table saws are great assets in every woodworking shop. In fact, it is the most useful tool in most shops. Ideally, table saw blades should rotate in a perfect circle without any deviations downwards or upwards or from one side to another.

So, what is runout on a table saw arbor? Well, in reality, there is a certain degree of inaccuracy in the blade’s path and “runout” is the term used to describe this scenario.

What is Runout on a Table Saw Arbor?

Table saw blades are expected to rotate in a perfect circle and without any deviation upwards, downwards, or from side to side. In the path of the table saw blade, there is a degree of inaccuracy and this is what is known as an arbor runout.

A runout may affect the quality of your cuts. In addition, it can put undue pressure on the motor and arbor. The greater the degree of the entry-level table saw runout, the higher the stress exerted. Runout can also become a safety issue as it increases the risk of kickback, posing a risk to your safety and to potentially damaging your table saw.

Wood about to be cut using a table saw

The Process of Checking Arbor Runout

Let’s take a look at how you can check for arbor runout in your table saw.

Confirm Presence of Runout

First, you will need to confirm that your blade really has runout. For you to confirm gross runout, you need to turn your table saw on and then off. As your blade slows down, you should look at the outer edge for any side to side movement.

If you do not see any side to side movement of the blade as it slows down, then it means that you do not need to tune anything up.

If you can notice this movement, then you are looking at about .010″ runout at the edge of the blade. This simply means that the blade that you are currently using is warped or the flange on the arbor of the saw requires tuning up.

Install a Good Blade and Recheck

You can install a high-quality table saw blade if possible and then recheck. If you have a good quality blade, you should then just check for runout on the arbor’s flange. The flange is the flat part of your arbor where your blade is pressed against whenever you tighten down your arbor nut.

Table saw arbor nut

Spin the Harbor

Next, you should unplug the saw. No woodwork enthusiasts or professional wants an accident while they are working. Mount the dial indicator on a magnet and then set it on your saw with its tip, reading the face of the plate in proximity to the outer edge.

Spin your arbor by hand and check the dial. As you go through the rotation, you should closely watch how much the dial changes between the highest and lowest readings. This is the amount of runout.

Check the Flange

You should then set up your dial indicator to check the flange. You can make the readings more accurate by setting up your needle to be as perpendicular to the flange as possible.

If you are lucky, the runout should be less than .005 on a 10-inch plate and .0025 on a 5-inch plate. If your flange runout is about 0.002 or less, you can just buy a good-quality blade and enjoy using your table saw.

The ideal way of testing the bearings is by listening to them when the saw is running. You can easily notice a bad bearing since the good ones are always quiet while the bad ones will make all kinds of unwanted noises.

Man trying to demonstrate what is runout on a table saw arbor

Related Questions

Before we finish this article, let’s answer a couple of questions regarding table saw wobbling.

How Can I Stop a Table Saw Blade From Wobbling?

If your blade wobbles, you should unplug the device and take out the blade. Look at the arbor for the amount of runout using a dial indicator. You should then fix the indicator’s base on the saw.

Ensure that the plunger is set such that it is perpendicular to the smoother part of your arbor nearer the threads.

Why Does a Table Saw Blade Wobble?

Bad bearings alone may not cause much runout or side to side wobble in saw blades. Wobbling can be caused by an old blade that is warped or because of heat that is produced during heavy cutting.

If your new blade wobbles, you should unplug your table saw, remove the blade, and use a dial indicator to check the arbor for runout.

Conclusion

As you continually use your table saw for your woodwork projects, the components of the devices can easily move out of alignment. This is why you need to check your device routinely and carry out maintenance for all the crucial parts. This will help to keep your table saw accurate and safe if it is done on a regular basis.

Furthermore, your medium range table saw will be clean and sharp to ensure accuracy and optimal operation and performance.

An expert at home repair, remodel, and DIY projects for nearly 40 years. His first experience came in completely restoring an antique home. Completely redone from the inside out, and restored to its original form, the home is a featured design by renowned Southern California Architect Cliff May, considered to be the father of the California Ranch Home. Now Dennis spends his time on fine woodworking projects and tool comparisons.