Miter slot to blade at 45° angle....

[Bill Huber]

I did not set the miter slot to blade at 45° when I set my saw up, just never cut 45° stuff until now....

So it is off, at 90° the blade to miter is at .001, love it but at 45° it is .014, way off.

The back of the blade is to the right by the .014, now to correct this I need to shim the back trunnion down.

I just don't understand this, is this not like just lowering the blade, how will this fix the problem?

I am getting this information for this site which is a very good write up on setting the saw.

http://www.americanwoodworker.com/bl...-tablesaw.aspx

[Andrew Hughes]

Hi bill its tru the top need to be at the correct axis or plane of the blade or trunnion.Its hurts my head just trying to figure it out.When I bought my first unisaw I took off the table to move the saw in my shop.I remember seeing a bunch of flat piece of shim stock on the ground.Of course I swept them up at the end of the day and thru them out.
By the time I realized I needed them they were gone gone gone.
From what I remember if the blade is heeling shim the back.If the cut burns at the start shim the front.
Took some trial and error and a dial indicator to get back.Hope this helpsAj

[Michael Weber]

There are better explanations on the web discussing the geometry and i tried to find the one I referenced when I aligned my cabinet saw with no luck. Your blade not only has to be parallel to the miter slot at 90 degrees but parallel to the saws table top when at an angle.

[Bill Huber]

Hi bill its tru the top need to be at the correct axis or plane of the blade or trunnion.Its hurts my head just trying to figure it out.When I bought my first unisaw I took off the table to move the saw in my shop.I remember seeing a bunch of flat piece of shim stock on the ground.Of course I swept them up at the end of the day and thru them out.
By the time I realized I needed them they were gone gone gone.
From what I remember if the blade is heeling shim the back.If the cut burns at the start shim the front.
Took some trial and error and a dial indicator to get back.Hope this helpsAj

I agree, it hurts my head also, I have been trying to get it straight in my head for a week and it is still not there. I guess it is one of those things I just have to do and not understand what I am doing....

Well when I think about it I do a lot of things I don't understand what I am doing.

[Michael Weber]

I found this thread I started a while back about the alignment. The link I referenced for the explaination was actually on a Rigid brand forum. Evidently the link to that document is no longer active. http://www.sawmillcreek.org/showthre...t=#post2161211 scroll to the top

[Andrew Hughes]

Since we're talking small amounts that need to be adjusted it's hard for me to wrap my mind around it.So let's say that table slots are perfectly aligned with the blade.Then imagine the table lifted one inch in the back still no problem with the blade at 90 to the table other than pushing up hill,Now imagine the blade tiled at 45 there no way one could cut anything,if someone even Tryd all hell would breack loose.The cut would bind.Aj

[Bill Huber]

Since we're talking small amounts that need to be adjusted it's hard for me to wrap my mind around it.So let's say that table slots are perfectly aligned with the blade.Then imagine the table lifted one inch in the back still no problem with the blade at 90 to the table other than pushing up hill,Now imagine the blade tiled at 45 there no way one could cut anything,if someone even Tryd all hell would breack loose.The cut would bind.Aj

That helped, I think I can see it now, well for a short time and then I have to think about it again.
But I have shims coming and I am going to get it shimmed up and correct at 45°.

Thanks all for the help......

[James White]

This may also be helpful.

https://woodgears.ca/delta_saw/alignment.html

James

[Andrew Kertesz]

Since I've never checked mine, I'm interested in how you measured this to find out your saw was off by that amount. Interesting thread to me at least....

[glenn bradley]

Since I've never checked mine, I'm interested in how you measured this to find out your saw was off by that amount. Interesting thread to me at least....

The same way you check it at 90*. Some sort of device that slides in the miter slot. Measure to a spot on the blade at the front, rotate this spot to the rear and re-measure.

Bill, you've got a lot of good info here. I will just add that once aligned at 90* and at angles, your saw will be a pleasure to use for those cuts. No more burning or tearout when cutting something besides 90*. It is so nice that when you need a long 22.5* edge you can just set the saw and rip this cut like any other. ;-)

[Bill Huber]

Since I've never checked mine, I'm interested in how you measured this to find out your saw was off by that amount. Interesting thread to me at least....

If you look at those links in post #8 or #1 you will see how it is done.
I use the Woodpecker Saw Gauge and a digital dial indicator, I just like the digital readout. I also use a Master Plate in place of the blade.

http://www.woodpeck.com/sawgauge.html

https://www.grizzly.com/products/Master-Plate/G7582

[James White]

Bill,

That gauge is very nice. However I do believe that it is not well suited for this 45 degree measurement. That is because the round bar stock that rides in the slot can move up and down with any variation in the slot width or depth of the slot. Including any little burs or debris in the slot. It is a very nice and elegant solution for measuring at 90 and the fence. However for this particular measurement any error in the slot can have a dramatic affect on the measurement. In my opinion using a well fitting miter gauge would give you a more accurate measurement. As it will ride on the table surface and only use the slot for left right alignment rather than left, right, up, and down that the Woodpeck gauge will give you. I hope that makes sense.

James

[Andrew Pitonyak]

Look at the image below. This is a side view. Think of the round thing as the blade, the bottom line as as a line drawn parallel to the trunion, and the top line marks the top of the table saw. In the first image, the trunion is aligned perfectly with the table top, the second one is so far out of whack that it would never have left the factory, but, the important thing to note is that if you are making a regular cut, it just does not matter at all.

bad_trunion_alignment.png

Consider the first image (top), if measure the distance from the line parallel to the trunion to the line parallel to the table, it is the same distance. from the trunion line to the table line. This is not even close to true on the bottom image.

Now, what happens if you tilt the blade 45 degrees along the trunion? Remember, you are not tilting with respect to the table, you are tilting with respect to the trunion. I won't take the time to attempt to make a three-D rendering, but, if you want, I can take a photo to illustrate, but, the moment you tilt with respect to the trunion, you have a point where the blade is at the same height as the table.

Intersection_Point.png

First, consider the distance from the trunion to the table top. If there is a big distance from the trunion to the table top, the table exits the table far to the left of the trunion. If the trunion is close to the table top, the blade is at the same height as the table very close to the trunion. So, if the trunion near the back is higher than the front, then when you tilt the blade, the front of the blade will be further to the left than the back of the blade.

[Bill Huber]

First, consider the distance from the trunion to the table top. If there is a big distance from the trunion to the table top, the table exits the table far to the left of the trunion. If the trunion is close to the table top, the blade is at the same height as the table very close to the trunion. So, if the trunion near the back is higher than the front, then when you tilt the blade, the front of the blade will be further to the left than the back of the blade.

GOT it that helped a bunch....

Thanks....

[Steve Baumgartner]

Here's an animation that should make it very clear what is happening. Note: depending on browser you may have to click on the gif to see it animate.

saw alignment.gif