- In today's video,
you'll learn how to calibrate your miter saw
so that your cuts are square and true.
Calibrating your saw simply means to check
or if necessary, adjust the saw
so that it's cutting as it's originally designed.
Now this not only needs to be checked on older saws
but surprisingly on newer saws as well.
The first thing we need to cover before getting started is
that there's two different styles
or types of fences that come on most miter saws.
The first is a two fence system
like what you see on this 10 inch Hitachi
and that simply means
that there are two completely separate fences
that are not connected.
And once you adjust one,
you'll need to bring the other one
into alignment with the first.
The second most common type
of fence is what you see here on the 12 inch D wall.
At first glance it looks like two separate fences.
But if you look behind the blade, you can see a rail
that connects the right side to the left side.
Why do I bring this up?
Because each fence style adjusts slightly different
than the other ones.
So you need to make sure you know
which one you have before moving on.
I do wanna quickly mention that it's very important
that you double check to make sure
that the saw is unplugged while you're making adjustments.
We're gonna be bouncing back and forth
between needing the saw plugged in to make cuts
and needing it unplugged to make adjustments
so please just be careful.
Alright, the first two things you need
to check regardless of what type of fence style you have is
how straight the fence is and how flat the table is.
To check for both of these you can use a good straight edge
like this one here, or a good quality level.
Just know that the straighter your straight edge,
the better your calibration will be.
To check the fence on a single fence saw
simply line up the straight edge
and check for gaps between the fence and the straight edge.
A great tool to help with that
and if you wanna get that precise,
is a good set of feeler gauges.
A feeler gauge is a simple group of thin metal gauges
that vary in size
and are used to determine the sizes of small gaps.
To use the feeler gauge along with the straight edge hold
the straight edge up to the fence and use a thin gauge
to see if you can get it between the fence
and the straight edge.
To check the table,
it's the same process using the feeler gauges
to get a sense of how flat the table is from side to side.
I personally have never worried about having my fence
and table absolutely perfect.
Somewhere around point 008 inches
or point two zero millimeters is just fine for me.
If your saw is out further than that
I would recommend continuing on
with this calibration process.
Because by the time you get to the end,
you might be satisfied with the way your saw is cutting.
The other options are to return this off if it's new,
replace it if it's old, or look up online
to learn the process of how the flattened them both.
Now I personally don't think
that the extra flattening is worth it.
But I'll let you be the judge
and the jury when it comes to your tools.
Moving on to check the fence on a two fence saw,
simply line up your straight edge on each fence separately
and check for gaps as before.
So after you've made sure that the table
and the fence is flat and straight,
it's time to move on
and talk about another important distinction.
And that is saws with adjustable detents and saws without.
For those of you that do not know detents on a miter saw
are use to quickly stop the saw
at specific miter and bevel angles.
On this double fence saw the detents are built in
and cannot be adjusted.
And on the DEWALT they can be adjusted
by loosening the screws that hold the detent in place.
Regardless of what type you have,
the next adjustments are gonna focus on making sure that
that zero or 90 degree detent is perfect,
because if that's good,
all the other angles will be perfect as well
unless there's something wrong with the detent itself,
which is extremely rare.
So let's look at how to adjust the miters on a to fence saw.
I recommend using a piece of test material
that's about as wide as your saw can cut.
If you have a sliding saw I would use a piece
that engages the slide function about halfway.
For simplicity today I'm using an eight inch
or 20 centimeter wide piece
to test the miter angles on both saws.
Before you make your first test cut,
make sure that the wood
that you're using has a nice straight edge on the back.
Once you're sure of that mark it with an arrow
so that side always stays towards the fence.
With the saw set zero make your first test cut.
(saw fussing)
Using the square check to cut to see
how well the saw is cutting.
It sometimes helps to hold the piece up to the light
to see if you can see any gaps.
You can also use your feeler gauges here
to help check if you're having a hard time seeing.
This cut is looking pretty good,
but I do see a bit of light coming through on one end.
At this point, let's check and verify
what we're seeing on the wood here is showing up on the saw.
To do that use the square and hold it against the fence.
Of course after you've unplugged the saw,
now lower the blade down starting by the fence side
and slide the square over
until it lightly touches the blade.
Most of the time it will be the teeth of the blade
that touch first if you're using a large square,
so if that's the case,
always use the teeth as your reference points on the blade.
However, if you're using a small square on a large saw,
it normally falls on the blade itself.
So if that's the case,
always use the blade as the reference point,
you can use the teeth or the blade itself for calibration.
Just make sure you're not on a tooth on one end
and on the blade on the other
because most likely that's gonna introduce an air
into your calibration.
Once your square is properly positioned look and listen.
You can see in here the blades teeth touching by the fence
but not touching away from the fence
because we can't adjust the detent on this saw,
you will need to adjust the fence itself
because the gap was here on the square
that means the fence on this side needs to move back.
There are generally two bolts that hold the fence in place
because we're looking to move really one side
or loosen the bolt on the outside slightly
and then I'll loosen the interval a little bit more.
That way I can get the fence to pivot off the outer bolt.
The key is not to get the bolts too loose
because you wanna loosen up that you can make an adjustment
but at the same time you want it tight enough
that once you do make the adjustment it stays.
Here's what this looks like.
While holding the fence in the square together as a unit.
I'll push the fence slightly away for me
while at the same time watching the gap close
between the blades teeth and my square.
It's hard to use the feeler gauge on this 10 inch saw
because of the blade size.
But depending on your setup,
feeler gauges may be helpful here
if you're referencing off the blade and not the teeth.
Once your adjustments are made,
tighten the fence slightly enough
to hold it in place and recheck.
We have to recheck because sometimes
when you tighten the bolts, the fence likes to move.
If you need to make a few more adjustments, that's normal,
take your time and dial it in and when you're all done,
tighten the bolts and recheck it one more time.
Now it's time to verify the accuracy with another test cut.
This time around, things are looking much better.
Like I said before,
if you adjust the zero degree detent or the 90 degree,
all the other angles will be good as well.
But let's check them by making 245 degree miters
and using our square to verify
that they are forming a true 90 degree angle,
which these are looking very good.
In case you're wondering I do recommend
these machinist squares, they work great, they're accurate
and to get a decent set is really not that expensive.
The last step here would be to align the right side fence
to the left side fence.
To do that you can use the same straight edge as before
and align the other fence carefully.
Again, making sure that when you tighten the bolts
that you recheck the fence just in case it moves.
With that process now complete let's move on to look at how
to make those adjustments on a single fence saw.
First step, make a test cut.
This one is looking pretty good.
But let's double check using the square
against the fence and blade.
As you can see on the 12 inch saw
there's a lot more blade to work with.
And you can get the square
to fit against the blade without touching any teeth.
Which also makes it easier to use feeler gauges
if you want to.
I'm noticing a slight gap here closest to the fence.
So let's fix that.
On this all we can adjust the detent.
So the first step is to loosen all the screws
that are holding the detent in place,
I recommend loosening them all
but leaving two of them slightly tighter than the other.
Again that way you can make adjustments with the detent
without moving around too easily.
Double check to make sure that the saw is still locked in
to the zero degree detent
and move this square over tight to the blade
but not putting too much pressure
which could distort the blade from its original position.
Tap the miter handle either to the left or to the right
to align the blade exactly with the square.
In this example, because the gap was towards the back,
the miter head needs to be tapped slightly to the right
and because the detent is loose,
as we move the saw head it automatically adjusts
the detent as well.
With the details set to its new position,
tighten back down two of the screws.
At this point you can grab a large square if you have one
and check the full travel of the slider.
This is looking really good
so you can tighten down the remaining detent screws
to lock it in place.
Of course double check your work and cut another test piece
and check the 45 degree cuts as well.
I did forget to mention that it's a good idea
to double check your degree indicators.
Sometimes those are gonna need slight adjustments as well.
Now that both saws are cutting accurate miters,
it's time to move on and check to verify
that the saw is making accurate bevels.
As before, it's a good idea to use a piece of test material
that is close to the max of the saws cutting capacity.
For the Hitachi here that's around four inches
or 10 centimeters.
With a piece marked with an arrow facing up, make the cut
and use your square to check how square the cut is.
I've already known for some time that this saw was out,
so it's no surprise to see a gap here on this end.
This saw doesn't have an adjustable detent for the bevel.
But what it does have is a stop pin in the back of the saw
that locks the head in place.
The only adjustment this saw has for the bevel is this bolt
that adjusts either in or out
to change the stopping point of the head.
Because these saw's head is slightly beveled
or tip to the right,
the saw head needs to be adjusted to the left.
To verify this you can either use a square
and position it flat on the table
and then writing up the saw blade.
Or you can use one
of these handy little digital angle finders.
To use this tool, simply turn it on, set it on the saw table
and press the zero button.
With that done, remove it from the table
and attach it to the blade.
What we're looking for is a readout
that should be 90 degrees.
But here that's not the case.
To just the bevel of this saw,
unlock the bevel adjustment lever
which is in the back again.
And then with a ratchet, turn the adjustment bolts
until you get a reading of 90 degrees.
Lock the head back down and do another test cut
and everything is looking good.
Because we made some adjustments,
if you look at the dial indicator,
you'll notice now that it's off,
sometimes you'll need to adjust those.
And that's easy.
All you have to do is loosen the screw,
slide the arrow over until you reach zero
and then tighten it back down.
The last thing to check here is a 45 degree stops.
Again, because this all doesn't have a detent for the bevel.
It has adjustable stops for the right
and left 45 degree cuts.
To see if those need calibrations,
we're gonna use our digital angle finder once again.
This time however,
we're going to zero out the angle finder on the blade
and then tipped us off first to the right,
we're at 45.2 degrees, so we need to make an adjustment.
And if you look on this side of the saw,
you will see the adjustable bolt,
turn that bolt until you get a reading of 45 degrees.
With that done, move to the left and do the same thing.
Now if you don't wanna spend the money
on a digital angle finder,
you can always use your combination square
or any other 45 degree square that you have in the shop.
As with the 45 degree miters,
let's check the 45 degrees bevels using two pieces of wood,
cut it 45 degrees, line them up
and use the square to verify the 90 degree angle.
With the 90 degree and the 45 degree bevel corrected
and the dial indicator is corrected all the other angles
in between will be good.
Let's quickly move on to the DEWALT saw
and see how to make those bevel detent adjustments.
For the sake of time I'm going to skip the test cut
and go right to using the digital angle finder.
First zeroing it out on the table
and then fixing it to the blade.
Here right out of the gate you can see
that it's off slightly it needs adjustments.
If I tip the saw to the right, you can now get a better view
of the bevel detent plate.
If you look close, there's actually three separate plates,
one in the center for the 90 degree detent
and then one on either side for the 45, the 33.9
and the 22.5 degree detents.
To adjust the 90 degree detent you'll have
to loosen all three nuts,
and then you'll be able to adjust the head
of the saw the left or to the right
until you get a reading of 90 degrees.
From there, tighten back only the center bolt
which locks the 90 degree detent in place.
After making a test cut and verifying
that the 90 degree is good.
We can move on to look at the right side
and left side bevels.
With the level box now zeroed out on the blade,
tip the saw to the right and lock it
into the 45 degree detent and look at your reading.
This side is actually looking really good
so we can tighten up the right side not.
Moving on to the left side we can see
that it does need adjusting.
On this particular saw,
we have an Allen screw here that acts as a stop.
Similar to the bolts on the Hitachi
that stops the saw at 45 degrees.
To dial the number in simply adjust the Allen screw in
or out until we've reached the reading
of 45 degrees on the digital angle finder.
With that set, lock it in place by tightening the last knot.
Again, because we already adjust the 90 and now the 45.
All the other angles in between should be good
unless there's something wrong with the plate itself.
And again, that's really uncommon.
Lastly, double check to see if the other dial indicator
needs moved after making these adjustments.
As before, it's a good idea to make 245 degree bevel cuts
and check them with your square.
Again, all these adjustments can be done with your square,
I just sometimes find it very helpful
and quicker to use the digital angle finder.
Before we end for the day,
here are four things to keep in mind.
First, on larger blades, like what's on the 12 inch D wall,
you may experience some flex in the blade
if you press too hard.
The idea is to press the square firmly against the fence,
but not as firm against the blade.
Basically, the softer the touch the better results.
In addition to that you should always calibrate
on a newer blade,
because the older blades may introduce some errors
into your calibration.
Second, this video doesn't cover all the available types
and brands of saws out there.
But it does cover the process of how to calibrate a saw.
So bottom line, you're gonna use the process
and what you learned.
And then you may have to figure out
how your particular manufacturer makes the adjustments.
Third, sometimes you need a square to check a square.
It's always a good idea to have multiple squares,
so you can check each one for accuracy.
That's one of the reasons
why I recommend the machinist squares
because even the inexpensive ones are good enough
for most woodworkers.
Now of course, you can buy more expensive squares
like woodpeckers brands, for example.
But they're really expensive.
I know a lot of you don't wanna spend
that type of money just on squares.
And lastly, number four, the ultimate test for miters
and bevels is building boxes or picture frames,
because the errors in woodworking
and carpentry often compound themselves.
If there's an error in the first miter.
By the time we get to the fourth miter
or corner of the picture frame,
the air will definitely reveal itself.
So I recommend that you take the time
to build some sample frames or boxes
with both miters and bevels.
Just make sure that each length
of the miter or bevel is the same.
You want to make an exact square or box.
If you find that the fourth angle is not fitting
as it should, you might need to recheck your calibrations.
Well I think that covers everything you need to know.
If you have questions, hit me up in the comments
or reach out to me on Instagram.
Thank you so much for watching
and supporting Training Hands Academy.
See you in the next video.
(upbeat music)