Why Are My Table Saw Cuts Not Straight?

I scratched my head, looking at the drunken zig-zag cuts. After meticulously jointing, planing, and measuring the wood, what had caused them to go so wonky?!

Before you sweep your crooked scraps off the table in defeat, let me show you how to troubleshoot uneven table saw cuts. By the end, you’ll know how to diagnose all the common culprits causing your wood to stagger out of that blade like a sailor on shore leave.

The Important Parts Of A Table Saw

We all know what a table saw is – a power tool with a blade and a table top.  But it’s more than that, so here are the important parts, some of which might be involved in causing the saw to make cuts that aren’t straight.

• Table: The table is the flat surface where the workpiece is placed. It should be made of a sturdy material, such as cast iron, and should be level.
• Blade: The blade is the part that does the cutting. It should be sharp and the correct size for the type of cuts you will make.
• Arbor: The arbor is the shaft that the blade is mounted on. It should be strong enough to support the weight of the blade and should be able to rotate smoothly.
• Motor: The motor powers the blade. It should be powerful enough to cut through the type of wood you will be working with.
• Fence: The fence is a guide that helps to ensure that the workpiece is cut straight. It should be parallel to the blade and should be adjustable.
• Miter gauge: The miter gauge is used to make angled cuts. It should be aligned with the blade and should be adjustable.
• Guards: The blade guards protect the operator from the blade. Your blade guard should be in good condition and should be used at all times.
• Dust collection system: The dust collection system removes sawdust from the work area. It is important to have a good dust collection system to prevent sawdust from getting into the air and causing respiratory problems.

In addition to these essential parts, there are a number of other features that may be found on a table saw, such as:

• Throat plate: The throat plate is a metal plate that covers the opening in the table where the blade passes through. It helps to prevent sawdust from getting into the motor and can also be used to help guide the workpiece.
• Splitter: The splitter is a small, vertical blade that helps to prevent kickback. It is located behind the main blade and should be used whenever possible.
• Riving knife: The riving knife is a long, vertical blade that helps to prevent kickback. It is located in front of the main blade and should always be used when making crosscuts.
• Safety switch: The safety switch is a switch that must be turned on before the saw can be operated. It helps to prevent accidental starts.

It is important to familiarize yourself with all of the parts of your table saw and to use them properly to avoid accidents.  It’s important to familiarize yourself, also, with its proper operation.

We want to eliminate user error.

What Are Some Of The Reasons Why Your Table Saw Is Not Making Straight Cuts?

We know the saw parts now, and among them are possible sources of problems contributing to bad cuts.

Blade Alignment

The blade should be parallel to the miter gauge fence and the rip fence. You can use a blade alignment gauge to check this.

Making sure your blade is square is easy – a framing square can tell you whether it’s square to the table.

Blades can be angled for bevel cuts, and sometimes we don’t return the blade angle to fully upright or 0 degrees on the setting.  Sometimes, too, the handle on the tilting apparatus of your saw will become loose, especially on an older saw. 

How often do you check for square on your saw?  Perhaps never. So, if your saw isn’t cutting straight, take the 30 seconds to check the blade angle.

Blade Is Loose

We know the blade is connected to the arbor by a nut.  Part of regular maintenance should include checking the nut for proper tightness:  not too tight, or the blade may stop mid-cut; too loose, and you will have a wobbly blade.

A wobbly,  loose blade will not make a good cut and can be very dangerous.  Proper blade attachment to the arbor is important.  

When checking the nut at the arbor, be sure to unplug the saw first.  Remove the plate that surrounds the blade unless you can get to the nut conveniently from the underside.

Check the arbor nut, being sure not to tighten it too much, but just tight.  This would be a good time, also, to check the square of the blade against the table.  This whole task will take just a minute or two, but it’s a worthwhile periodic check.

Dull Blade/Warped Blade

A dull blade will not cut cleanly and will cause the saw to wander. Be sure to sharpen the table saw blade regularly.

As for a warped blade, this is not quite as easy to diagnose unless the warp is rather pronounced.  Nonetheless, you will want to check for a warp as part of your diagnosis.

We use different types of wood in our shop, some hardwoods, some softwoods, and unless we are using the right blade for the wood being cut, hardwoods can introduce a bit of a warp on a blade that should otherwise be used when cutting softwoods.  It can also harm the blade teeth.

Make sure you are using the right blade for the job.

Be careful, also, how you push the wood against the blade and the fence.  Keep the wood flat on the table, being careful not to lift the wood as it comes out of the cut; make sure, also, the wood is tight against the fence.

Fence alignment issues can affect the straightness of the cut, as you might expect.

Having said that, do not push the wood too hard against the blade, or you run the risk of warping it even slightly.  Also, do not push the wood to hard against the fence, or again you risk warping the blade, and your pieces of wood will not be cut straight.

Flat on the table surface, pushed adequately against the fence, and pushed against the blade with your push stick only enough to let the blade do the cutting, will give you a straight cut.

Wood Not Properly Supported 

The wood should be firmly held in place against the fence or miter gauge. If it is not, it will wobble and cause the saw to cut crookedly.

This has to do with user error and so is easily corrected by educating yourself on a table saw’s proper use. With experience, this will likely disappear, and your piece of wood’s cut will be straight.

The saw is Not level 

The saw should be level from front to back and side to side. If it is not, the blade will not cut straight. This is pretty basic, and no further explanation is necessary except to say checking for level should be a part of your regular maintenance of the saw.

Fence Not Parallel To Blade.

The fence should be parallel to the blade so that the wood is cut evenly. Be sure to tighten the fence into place, and make sure it is parallel to the blade and held in place well.

If the fence moves during cutting, the cut will not be straight.  Also, check for a misaligned fence.  A misaligned fence issue will also affect the straightness of your cut.

Over time, a rip fence will become a bit loose.  We know it is essential to a straight cut that the fence be both properly aligned and tightly in place.  Take your time in setting the fence, and double-check alignment by using two points of reference – the front and back of the blade, for instance, or the front and back of the miter slot.

The miter gauge Not Aligned Properly

The miter gauge should be aligned with the blade so that angled cuts are made accurately.

Enough said.

Operator Not Using Saw Properly 

The operator should be using the saw properly to avoid making crooked cuts. This includes using the correct saw settings, holding the wood properly, and applying the correct amount of pressure.

Poor form is going to contribute to bad cuts.  Take the time to know your table saw; engage in regular maintenance to keep it performing as it should; 

If you are having trouble getting straight cuts from your table saw, check these things first. Once you have addressed any of the potential problems, you should be able to get straight cuts.

A Few Other Tips For Getting Straight Cuts From Your Table Saw

• Use a sharp blade. A dull blade will cause the saw to wander and make crooked cuts.
• Make sure the wood is properly supported. The wood should be firmly held in place against the fence or miter gauge.
• Use the correct saw settings. The saw should be set to the correct height and angle for the type of cut you are making – just above the thickness of the wood being cut and 90 degrees for the most common cuts.
• Apply the correct amount of pressure. Too much pressure can cause the saw to wander, while too little pressure can cause the cut to be uneven.
• Practice makes perfect. The more you use your table saw, the better you will get at making straight cuts.  With experience, the checklist you can develop from this article will ensure your cuts are always straight.

Do not assume that there is only one issue preventing a straight cut on your saw.  There could easily be more than one reason from among those mentioned above. 

Again, regular maintenance of your power tools, including your table saw, will keep them functioning properly and keep you safe.

Checking all of the possible causes identified in this article as a part of your ongoing tool servicing will result in safer operation of them, including your table saw, and better results for your woodworking projects.

That sheet of plywood you are ripping will have the straight edges you need for your project.  In woodworking, we know that straight edges are good and crooked edges are bad.

So, follow our recommendation for periodic checking of everything on your table saw, and you’ll get those straight edges every time.

Last update on 2024-12-01 / Affiliate links / Images from Amazon Product Advertising API