Tune Up Your Table Saw With a 2x4




About: I'm a born tinkerer who's always enjoyed hands on activities. I'm into 3D printing, CNC carving and milling, woodworking, and many other trades and crafts. I'm always coming up with ideas for new inventions ...

Getting accuracy and performance out of your table saw is dependent on how well you have it tuned and calibrated. Fortunately, a wealth of information exists on this topic. Unfortunately, many of those guides have you use expensive jigs, fixtures, and measuring tools to make your saw cut square and true. While this is very nice and quite precise, it's overkill for many of us. The truth is that no matter how well your saw is adjusted, if anything is out of alignment you'll be able to tell from the pieces that you cut and how they fit together.

This guide will show you how to use a 2x4 and a basic understanding of simple geometry to dial in your table saw.

Step 1: Understanding the Geometry of a Saw

Before we start making adjustments, it is important that you understand the geometry of what makes a good saw work well. There are 5 primary alignments and dimensions that need to be taken into consideration.

Table to Blade Alignment: When viewed from above, the miter slots in your table need to be perfectly parallel with the blade so that you can push a piece of wood straight through the saw without catching and binding on the width of the blade. If this adjustment is off and your blade is canted, you'll notice arcs from the blade's teeth scratched into the surface of your cuts.

Rip Fence Alignment: Your fence needs to be parallel with the miter slots and blade so that the pieces you rip against it are a consistent width and don't wiggle or bind against the blade. Inaccuracies in this adjustment can cause binds and kickback. You do not want to encounter either of these failures EVER, they're unpredictable and dangerous!

Miter Gauge Angle: The pointer on your miter gauge should read accurately so that you can precisely cut at any angle that you want. Most of the time you'll want a 90 degree miter angle so that the pieces you crosscut will have square corners.

Blade Bevel Angle: When you look across your saw from front to back, it's important for the blade to raise through the table at the proper angle. Most of the time, you'll want the blade to be exactly 90 degrees from the table, but certain jobs will require other bevel angles. Most saws have 'stop' points built in at 90 degrees and at 45 degrees. Making your indicator needle and stop points accurate will be critical to the consistency of your cuts.

Rip Scale (cut width) Indicator: You want the measuring tape on your guide rails to reflect the exact position of the rip fence and accurately show the width of the piece that you'll be cutting.

Step 2: Clean Everything - You Don't Want to Measure Dirt

First, you'll want to clean your saw. If you have dirt and grime built up, it can effect your measurements and calibrations. Take the time now to remove all of those globs and deposits so that your tune up can be as effective as possible. Clean, shiny metal is your goal.

  • The table should be rust free and clear of chips and debris.
  • Blow the sawdust out of your saw (don't forget the inside) and wipe down the motor, belts, and pulleys.
  • Your blade should spin freely and have no wobble.
  • You want the lead-screws that adjust blade height and bevel angle to turn smoothly.

**Safety First**

A table saw is a very dangerous tool. People can and do encounter serious danger and injury while using them. I know people who are missing fingers because of a table saw - it's no joke. When you are not cutting a piece of wood, always have the saw unplugged and 'locked out' for safety - especially if you are working on the saw and will have your hands all over the moving parts.

My saw has a lockout tab on the power switch, I pull the plug out of the wall AND remove the lockout tab so that I have two layers of protection in case of human error.

One more note: Always use a guard over your blade. I removed mine briefly for pictures and measurement. A table saw is dangerous to operate without one.

Step 3: Measure the Blade to Table Alignment

Cut off a small chunk of 2x4, and run a drywall screw into the end of it. You want the screw to be close to one of the shorter edges of the board.

Pick a clean tooth on your blade and mark it with an X.

Clamp the board with the screw against your miter gauge, and rotate the blade so that the screw is just touching the tooth that you marked earlier.

You want the marked tooth to just slightly graze the surface of the screw as you move the blade back and forth. If there's any pressure to speak of or an air gap between the tooth and screw, loosen your clamp and lightly tap the board back and forth until you get the perfect tolerance. I find that a screwdriver handle makes a nice tool for tapping and nudging fine adjustments like this.

After getting the tooth lined up perfectly in front, slide the miter gauge back and turn the blade so that the same screw and X marked tooth align on the back side of the blade. You want to see the exact same tolerance here; the front should match the back.

If the tolerance is different between the front and back of the blade, you need to make an adjustment. On most contractor grade saws, the blade is mounted on trunnions beneath the table that can be loosened and adjusted for the perfect alignment. Cabinet style saws generally have fixed trunnions and require adjusting the table... This exact procedure will vary by model and manufacturer, so it's best to consult your saw's original owner's manual for more details.

Step 4: Align Your Fence With the Miter Slots

After your table and blade are precisely aligned, you'll want to make your rip fence parallel to them. The easiest way to do this is to move the fence just above one of the miter slots and to eyeball the resultant gap. You want it to be even and parallel all the way from front to back.

If there's any variation in this gap, you need to adjust it out of your fence. My saw has two bolts on top of the fence that you can loosen, realign, and tighten to change the fence angle. Your saw may be different, so once again, check your owner's manual for the exact procedure for your saw.

Another way to check this alignment is to cut two slices of wood that fit snugly in the miter slots and to slide the fence up against them to check for gaps. You can even do this with a feeler gauge, if that's the level of accuracy that you are aiming for.

Step 5: Check Your Miter Gauge

Adjust your miter gauge so that the pointer is perfectly on 0, indicating that it's perpendicular (90 degrees) to the blade.

Next, mark a piece of 2x4 with an A and a B so that one letter will be on each side of the crosscut that you'll make next.

After the cut, you should have two pieces just like this.

Flip over one of the pieces, so that one is facing up and the other is facing down.

Press both pieces flat against your miter gauge, and check for a gap in the seam between them. In this picture, you can see that there is a gap at the top. This indicates that the miter gauge needs to be adjusted slightly counter-clockwise to be at a perfect 90 degree angle with the blade.

Make your adjustment, and cut another piece to test the alignment. When you have everything just right, there will be no gap.

This works because two 90 degree angles form a straight 180 that you can compare against a known flat surface like the miter gauge. If your 90 degree cuts are inaccurate, laying the boards this way will double the inaccuracy and highlight the misalignment enough that you can see it. That, in a nutshell, is the magic that makes this whole calibration process work!

After you're satisfied with this adjustment, loosen the indicator needle on your gauge and adjust it so that it reads accurately.

Step 6: Check Your 90 Degree Bevel Stop

Next we will adjust your blade's bevel angle.

Most saws have a stop collar on the bevel angle lead-screw so that the blade can't travel beyond 90 degrees in one direction and it can't go past 45 in the other. Adjust your blade so that you're against the 90 degree stop and the blade is vertical.

Again, we're going to mark an A and a B on each side of the blade and crosscut a piece of 2x4.

Make the cut, and flip one of the pieces over, just like before.

This time, we'll be using the table top as the reference straight edge, and you want to look for a gap on the side of the pieces that you've just cut. This picture shows that the pieces are tight on bottom and have a gap at the top. The blade is tilted past 90 degrees and needs to rotate counterclockwise to be right on 90 again.

The 90 degree stop on my saw is a threaded collar with 2 brass set screws. To adjust it, I had to loosen both brass screws and thread the collar in and out until I found the sweet spot that gave me repeatable 90 degree cuts. Don't forget to tighten the set screws between adjustments, and once again after you're finished just in case.

A perfect 90 degree bevel will yield cuts with no gap. After you get this dialed in, you should adjust your pointer so that it reads accurately.

Step 7: Check Your 45 Degree Bevel Stop

Next, rotate your blade against the 45 degree bevel stop.

Before we continue with this step, a note about safety and bevel cuts: never crosscut a board with your miter gauge under the bevel angle (to the left on most saws). If anything slips, the wood will bind and be pulled under the blade, which is the last place that you want your miter gauge or heaven forbid, your hand, to be.

Once your blade is positioned at 45 degrees, and your miter gauge is on the safe side of the blade, you can make your first cut. This time, we need to cut 4 pieces to have angles that add up to 180 degrees.

Note that this image is just to show you the pattern that the pieces fit in, it is not the orientation that we'll set them in for measuring.

Once you've made all of the cuts, use the table top as your reference for flat. Assemble all 4 pieces, and press them against the table to check for gaps.

The above image shows a gap caused by the blade being tilted beyond 45 degrees. To make a perfect 45 cut, the blade needs to rotate clockwise, and the bevel stop for 45 degrees should also be adjusted. Just like before, repeat this process until you achieve a perfect angle with no gaps.

Step 8: Adjust Your Rip Scale Indicator

Set your rip fence so that it's just less than the width of a 2x4 from the blade. Lock the fence in place, and rip the board using a push-stick. Move the fence about 1/4" closer to the blade, and rip the other side of the board. The goal is to end up with a board that has sharp, square corners instead of the radius that 2x4's have from the saw mill.

This will make it much easier to see where the edge of the board hits the graduations on the measuring tape.

With the fence still locked from the second cut, you can set your newly ripped board over the fence's scale to see how accurate the cut was. Align the left side of your piece right on the 0 mark, and keep it there. Then, look to see if the horse-hair on the fence lines up with the right edge of the board or not.

You can loosen the screw on the viewing window and slide it back and forth to adjust the measurement that your fence reads.

Repeat this process until the board that you cut lines up perfectly at both ends of the scale.

Step 9: Other Handy Tweaks and Adjustments

Now that you've got the main things crossed off the list, here are a few other tips that will help you get things cutting like butter.

  • Make sure that your table extensions are flat with the rest of the table top.
  • Level your saw so that gravity doesn't make your boards wander 'downhill' as you cut.
  • Adjust your fence to be an even height above the table.
  • If you have blade wobble, find out why. Something could be dirty, warped, bent, etc. Find it and fix it.
  • Ensure that your belts and pulleys are turning in the same plane. You want everything inline.
  • Use a product like Johnson's Paste Wax to seal and lubricate your table. It's also nice to lubricate your fence.
  • Use tools and accessories that will make your life easier. Push sticks, feather-boards, blade changers, blade stabilizers, etc will all make your table saw experience safer and easier.

Most of all, be safe and enjoy your table saw!

Thank you for reading, I'll see you in the comments section!


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    30 Discussions


    1 year ago

    Thank you very much for this write up. It is the BEST Instructable I've read yet. Clear, concise, no assumptions the reader is smart enough to figure out. All steps included. Excellent!

    This wasn't rocket science. It isn't difficult. Just plain practical common sense stuff that I - didn't figure out on my own.

    Again - thank you!

    PS - I'm glad I didn't buy any of those expensive fancy calibration tools! I have tons of 2x4 scrap laying around.


    1 year ago

    Thank you for this! I am new to woodworking and financially can't afford expensive tools (the saw or gauges to measure it) so this was a huge help in allowing me to get better more accurate cuts. THANK YOU!


    1 year ago

    The 2x4 test worked great! thanks for the trick!


    3 years ago

    Well done on the instructable Jim. One quick suggestion / tip if I may :

    On the adjustment tuning of the board with the screw for setting the blade to table alignment in step 3. Instead of loosening the clamp and tapping the board back and forth, just turn the screw in or out. You'll get much easier and finer adjustment doing that.

    3 replies

    Reply 1 year ago

    The tooth is contacting the screw at a different point on the face of the screw. The tolerances for screw manufacture simply isn't as precise as it's being used for here, nor is it's insertion into the piece of wood -- if the screw isn't absolutely square to the block, and parallel to the table, the head of the screw will be on a different plane than the saw blade. A proper dial indicator is the tool to use here.

    In the spirit of this instructable seeking to achieve the tuneup using a 2x4 and minimal additional tooling, ripping a thinner scrap of 2x4, say to 3/4 or 1" thick, driving a screw through that so that the point penetrates out the back and the head seats fully, then screwing that block into the remaining stock that is to be clamped to the mitre, but with the screw point facing outwards will give you a fine point to contact the blade with - a point rather than the not-necessarily-planar screw head. Put that modified block on the mitre (loosely clamped) and adjust it to just contact the leading edge of the saw tooth, tighten the clamp and do your tap adjustments if still necessary. Now, when you slide it to the rear of the blade and rotate the tooth into place, you have just one point to contact and have eliminated planar error.

    Note that checking and correcting for slop in the mitre gauge rail should be a step that is taken before using the mitre gauge to square anything.

    The belt should be removed from the arbor and the blade/arbor checked for slop. With the belt in place and tensioning the arbor, you might not readily notice the propensity for movement, but when the motor is running and the arbor is under varying loads as you feed material, that could cause it to wobble.


    Reply 1 year ago

    Great points, thanks for the followup !


    Reply 3 years ago

    I just found this instructable and should have read the other comments a little deeper before posting, I was beaten to the suggestion by a month :-)


    3 years ago

    Lots of good tips here. One reminder about the Rip Scale Indicator settings is that it will change if you use different thickness blades. Some of my blades are 1/8" and others 3/32".

    1 reply

    Reply 1 year ago

    Bummer that left tilt, right fenced saws have the arbor opening on the fence side -- if not for that, then the fixed face of the arbor would be consistently at zero.

    You can get shims for blades which address this. Precision dado sets would include some, but there are other sources.


    3 years ago

    Nothing wrong with this method!

    For anything relating to my blade or fence I use a $10 dial indicator. Don't have to sharpen my blade after i do all the cutting this method requires ? And the accuracy can be in thousandths and doesn't require sight comparison. For checking the 45 angle a cheap harbor freight or box store tri square is all you need. Fence alignment with blade or mitre slot, again with the dial indicator.

    PM me if you can't figure out the dial indicator method.


    3 years ago

    Lots of very good information and instruction here, and I want to thank you very much.

    I thought the idea of using the screw in the 2 x 4 in Step 3 was marvelous, but why didn't you use the screw (screwing it in or out as an adjustment) instead of loosening the clamp and tapping the whole block? When reading this, I thought that was the reason for the screw until I read further. Putting a small piece of masking tape over the screw head and turning the saw blade until it just scrapes the tape is a good way to tell very closely where the blade tooth is.

    2 replies

    Reply 3 years ago

    Heh :-) I guess I was late with the suggestion. I just found this instructable and made the same observation about the screw adjustment before reading down far enough in the comments. You beat me to it !


    Reply 3 years ago

    Great ideas, I like them both!

    I used the screw so that I had a precise, small contact point to give me repeatable results... Using a screw for adjustability didn't even cross my mind. Chances are that you'll find the perfect spot by hand the first time anyway, but if you do need to make adjustments, either method would work well. Especially if your setup used a more elaborate measurement fixture that didn't adjust as easily as a squeeze clamp, a screw would be a life saver!

    Love the tape idea. If you've got an expensive blade, you're not making metal on metal contact with it, then. The indentation on the tape would also give you a visual indicator of when there was contact.


    3 years ago

    Great stuff Jim!
    Learned a lot... will be checking the accuracy of my table saw!


    3 years ago

    Very well done. Thanks for taking the time to this. It should be of much help to folks who don't have the "fancy", and oft-time expensive, tune-up tools.


    3 years ago

    That's a great 'structable' not using any expensive equipment means anyone can check and adjust their table saw. I'm going to check mine as soon as I finish some unrelated projects


    3 years ago

    Great 'ible, clear and simple instructions. Will make truing the saw easier.



    3 years ago

    I bought a new saw for Christmas. Your instructions made me realize that there was problems right out of the box... got them resolved though. would love something similar for a miter saw.

    Thanks for a great instructible.


    3 years ago

    jimustanguitar, great job on the tune up instructions using a 2x4. Your instructions and pictures will make it easy for anyone to calibrate their table saw and other carpenter shop tools. Good tip on maintenance of the table and fence. Good luck in the contest.

    1 reply