I know how frustrating it is to try to assemble a project when the boards are 'almost square'.

Table saws that are new out of the box can't be counted on to provide accurate cuts. Invest in one of the dial indicator sets to establish the table slots parallel with the blade. especially avoid having the back edge of the saw coming into hard contact with your boards on your thru cuts. A few thousandths 'fall off' is actually good.

There is probably little hope for your miter gauge. Set it aside for quick rough cuts.

I can recommend INCRA's miter express for precision work. With it you can crosscut boards 24" wide with confidence. Even with this accessory you will need a precision combination square, not one from the hardware store, in order to set it up precisely.

 

Get the Incra 100SE. All the gauge you'll ever need. It can be well tuned to fit the miter slot in your saw. Most gauges that come with saws are junk.
Bill

 

Build a crosscut sled and you will never regret it. I have one of the ones from a The New Yankee workshop episode but there are a bunch of ones on this site that vary from pretty simple to very complicated.

 

if you cut 24 inch would probably really see that worse …....... because it magnifies itself that's why you done see it in 8 inch so much ….......I would build a crosscut sled

 

Osborne makes a miter gauge that might suit your needs as well.

 

+1 on the crosscut sled. It need not be fancy.

You mentioned that you got good results when ripping plywood. I assume that was done using the fence. That shows the blade and fence are parallel, but it does not prove that the blade is parallel to the miter slot. You should start by establishing the latter, and then make a sled. Trying to crosscut a 16" board with just the miter gauge is going to be difficult. The sled makes it a piece of cake. Don't forget to adjust the fence so that it is parallel to the blade.

 

AAANDRRREW,

If the table saw is your go-to machine for making crosscuts, I agree that a well thought out table saw crosscut sled or panel sled is a great way to go. In the meantime, here are some thoughts regarding the problems you have encountered.

If the table saw fence is parallel to the blade and you have a framing square that is truly square, then the mitre gauge can be squared to the blade using the table saw's fence. Place the framing square so that one leg is in full contact with the table saw fence, which is locked in place. Then the mitre gauge fence is brought into contact with the other leg of the framing square. The mitre gauge is adjusted until the mitre gauge fence is in full contact with the leg of the framing square. I board that is known to be square could be substituted for the framing square. I find using a known square board easier. Architect drafting triangles can be similarly used for those common mitre angles.

Since there is some slop between the mitre gauge bar and the table saw's mitre slot, squaring the mitre gauge to the table saw fence is best done by ensuring the mitre gauge bar is in full contact with the left or right side of the table saw's mitre slot. Also, when the cut is made the mitre gauge bar should be kept continually registered against whichever side the table saw's mitre slot was used when squaring the mitre gauge.

By turning the mitre gauge around so the bar is pointing toward the operator, head of the mitre gauge can be kept on the table saw. The mitre gauge can be turned around so that the leading edge of the board rests against the mitre gauge fence. The cut is made by pushing the board while holding the leading edge of the board firmly against the mitre gauge fence.

But even this method has its limitations. If the board is too wide, the head of the mitre gauge can slip off the outfeed end of the table which could spoil the cut or result in an accident. Also it is a dangerous technique if the operator must lean over the table saw to complete the cut, made even more dangerous if the cut is made with an unguarded blade. There are some cuts which are just too awkward or dangerous to be performed at the table saw. In these cases, figuring out an alternative safer method is, I think, best.

 

I have that issue occasionally and a quick check of the miter head is easy to do.

1. Turn the miter head over
2. Put it back into either miter slot.
3. Move the miter head into contact with either the back end of the TS or against the rip fence guide on the front of the saw.
4. This assumes that the miter slot is square with the TS top casting and should indicate the "square" of the miter head!

 

If using a framing square make sure it's square. I've had a framing square not to be square that lead me to think my table saw square was not accurate. I made the mistake thinking the framing square was accurate.

 

As JBrow mentioned, setting the miter gauge to 90° using as square is the way to go, You can either use the fence or even the other miter slot as a reference. I highflying recommend making a cross cut sled too. It not only makes it easy to make perfect 90° cuts with no setup but it is often much safer too. If you can't get the slop our the slot, you can try shimming the bar it using aluminum tape used for HVAC ducts.

Also, you did not mention whether you adjusted the miter gauge after you got the saw. There are 2 things that can be adjusted. First the positive stops for 90, 45 and 60° and second, the scale on the miter gauge can be adjusted so it is more accurate by loosening the set screws on the bottom and sliding it slightly so that it is on 90 after you have used a square to set the angle.

 

+10 on building a crosscut sled.

Even though I own the Incra MITER1000SE Miter Gauge, I built a crosscut sled and have NEVER looked back. Here's mine:
.
http://lumberjocks.com/projects/57667

I have a couple links in my OP that you might find useful. Good luck!

 

Your square isn't square. Squares from the mass marketers probably aren't accurate enough for your need. For accurate set up on my jobsite Bosch I use Whiteside brass set-up bars and then a pair of aluminum "assembly squares" from Woodpecker / Pinnacle. The equipment that I named is damned accurate and so I expect that these will change your life for the better.

The above-cited Inca is great, but you still face the issue of initial set-up and for that I refer you to paragraph #1.

 

Another issues I have, i can pull the miter gauge off the table far enough to get the 16" board on the table. The front of the miter gauge is still in the slot. But as I slide the piece through the saw, the miter gauge gets caught on the edge of the table and I need to stop, lift up slight on the miter so it can clear the table, then proceed…very irritating and not safe at all.

- AAANDRRREW

You should not try cross cutting pieces that wide if the miter square head is off the table top. I have the Delta 36-725 and 12 inches appears to be about the widest you should cut using the miter square. In my opinion the miter square that came with the 36-725 is better than most miter squares I've gotten in the past with table saws. That being said, I did buy an Incra miter square that rides smoother because it has nylon adjustment washers to hold it tighter in the table slot.

 

As said, don't trust ANY square unless you've verified it.

+10000 on making a cross-cut sled. Be sure to square it up using the 5 cut method. With some effort, you can get the sled square enough that the error is perhaps 10 thousandths over a 20" cut.

I have a small sled, wide enough for 13" boards, and a big sled wide enough for 36" cuts. That's a great thing when cutting cabinet panels.

Here's a link to building a sled and more importantly a good description of the 5-cut method for checking squareness.

By the way, sleds make it very easy to start cuts where much of board and the sled and sled are hanging off the table. You still need to hold it up, but it's one solid unit. And if you have a really big sled, and don't want to hold it, you can setup a roller stand to hold it up.

Make a sled or two. Just do it. I'd say it is the most useful table saw accessory and right up there with a fence.

 

Thanks for all the great advice guys.

I had been using a combination square to square things up. Nothing fancy - picked it up from menards a couple years ago. Not saying it's square, but I'm confident its close because I did use it to verify my new miter saw was square out of the box, which it was. I do have a large framing square, but I haven't used it to set my saw up.

Makes complete sense though about having a sled. I'm still rather new to all this, and once people started to post about building a sled, I do remember my buddy and his dad (who builds cabinets as a side gig) using a sled to cross cut pieces for a tv stand they were helping me build.

As for the miter gauge - I think the one I have is good enough for building chicken coops and swing sets, but for finer things I'll look into the Incra ones - I do like how they have what looks to be teflon adjustments on the slide versus the set screws. My screws are kind of loose and at times they move and as I'm all set to make a nice cut, one of the little SOB's catches on edge of the slot and I have to stop, retreat, turn it in and try my cut again, many times after I've already started cutting… rather frustrating.

 

With a little tune up, the miter guage will handle 90% of the cuts you need to make. There are set screws on the side of the bar to adjust for the slop between the slot and the bar and 3 screws on the underside of the scale/presets detents to fine tune the angle presets.

If you need info on how to make and tune a crosscut sled William Ng has a good video that explains how to use the 5 cut method to get darn close to perfect 90° cuts.

The video is sort of in the wrong order. He first shows how to tune it and later shows how to make a simple sled. When you do make sled, don't cheap-out on the plywood. Everything needs to be nice and flat to get accurate cuts.

 

Sleds are great and also good for safety and control of the workpiece.

But get a plastic drafting triangle for a buck or two at Walmart in the office section, and put one edge on the blade, the other on your miter gauge and make the blade and guage square to eachother.

 

I agree with the previous poster that the Wm. Ng video out there is the best for building and setting up the fence on a new table saw sled. Also, the Incra miter gauges are tops…IMHO. Check the squareness of your combo square too. If it is out of square, then all of your setups using it will be out too. Welcome to the woodworking disease. Once afflicted, you will have it for life, and find that is it a very rewarding pastime. Good Luck - Work Safely - Have Fun !!

 

The incra has an easy adjustment to make it accurate and tight in the slot and a separate adjustment to zero it. I'm very happy with mine, even making six and eight sided items I get tight joints.

 

I built a simple but effective crosscut sled, which makes the cuts on wide boards a lot easier. As for the miter gauge, getting my two absolutely square to the blade and fence (and keeping them that way) was difficult for a number of years. I cut a few angles and then I'm out of square again and have to fiddle with the miter gauge again. It was a bother. I found the solution in a woodworking magazine, which was (once the miter gauge is square again) to cut a gauge reset board to speed up and simplify squaring up the miter gauge. My reset board is about 24 inches long and 6 inches wide, cut from good plywood. I can unlock or unscrew the miter gauge, hold the long edge of the reset board against the miter gauge and put the short edge square against the fence. Tighten the miter gauge lock and you're done. Takes seconds. I have the board hung on the wall near the saw.

 

Sleds are great and also good for safety and control of the workpiece.

But get a plastic drafting triangle for a buck or two at Walmart in the office section, and put one edge on the blade, the other on your miter gauge and make the blade and guage square to eachother.

- DrDirt

First I recommend instead that you go to Staples, Office Depot, or Office Max and get one of the nicer 10 or 12 inch drafting squares. Those are reliably square. They are not the most convenient format for all situations, but they are more than accurate enough for woodworking.

Second, squaring the miter gauge fence to the saw blade is not as accurate as squaring the miter gauge fence to the miter gauge runner. If you have set screws sticking out one side of the runner then reference the opposite side of the runner. Ideally the blade is perfectly parallel to the miter slots, so the difference in accuracy is a non-issue, but not all situations are ideal.

Third, it is very easy for the saw blade to pull the work one way or the other along the miter gauge fence thereby changing the angle of the cut a bit. This is less of a problem with skim cuts on narrow stock. Using a stop on your miter gauge can help. Further, how you push the work through the cut can also affect the cut a bit. A crosscut sled that allows you to clamp the work firmly to the sled helps both of these issues; with one you can focus on sliding the sled through the cut smoothly and consistently to get smooth and consistent cuts where you intended to get them. I like to use aluminum T track for sled runners. It will fit loosely in the track so I apply a bit of pressure on the sled towards the blade when I'm making the cut. But you still need an outfeed table so you can focus on making the cut and are not also trying to keep everything from falling off the saw table at the end of the cut.

You are also likely to find that if you consistently pay attention to your work that your results will improve as you gain experience. It seems that a beginner can do everything right and still get inconsistent results whereas an experienced operator can seem to get good results most of the time without much effort. Experience makes a difference.

 

If the fence is not square (reference edge) you will see it in a number of ways.

To show this, with the saw off, using a carpenter's square, square the miter to the fence. Turn the square around and put it against the flat of the blade (not the teeth), run it up the side of the blade an pull it back. Do this with the long side of the square.

Doing this on each side of the blade, the square should not lose contact with the blade.

If the blade maintains gentle contact on both sides, your miter and blade are square with each other

 

That's too wide a board to crosscut with a miter gauge.

Definitely make a crosscut sled. I have not used my miter gauge half a dozen times in the eight years I've had my Delta Unisaw. You can do a four-cut test on a sled and get it dead solid. The miter gauge will disappoint you every time.

The only other answer is to buy an after-market crosscut guide. I'd do the sled for sure. Use good half inch plywood and hardwood for runners and fences. There are plenty of uTube videos to show you how.

 

another thought, make a shooting board and get dead on square by leaving a 32nd or 64th. If you're not doing production work, and more hobby, this is a easy solution and ball accurate