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/blogs/tools/archive/2009/10/05/accurize-your-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/showthread.php?208299-Live-and-Learn-Aligning-a-saw-when-blade-is-angled&p=2161211&highlight=#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 (http://www.woodpeck.com/sawgauge.html)

[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.

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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.

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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.

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[Chris Merriam]

Wow, after years and years of reading about table saws I never even realized you had to check alignment at 45 as well as 90, I've learned something new today!

Bill just FYI, I was able to buy brass shim stock locally in a combo pack with different thicknesses. I bought it from a Remote control+Train hobby store. I think (not positive) that Hobby Lobby might have it as well. Sounds like you've ordered yours already, but posting this for anyone else needing shim stock.

[Ken Fitzgerald]

Bill,

Professionally when I need shim stock, locally I was able to get it at a local machine shop.

[glenn bradley]

And I'll add that aluminum can cut-outs have been working for me for years ;). Not much help when you need an in between thickness however.

[Andrew Pitonyak]

[QUOTE=Steve Baumgartner;2378223]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.[/QUOTE

You "da-man" Steve! :D

[Ken Fitzgerald]

And I'll add that aluminum can cut-outs have been working for me for years ;). Not much help when you need an in between thickness however.

a skillfully applied hammer to different thicknesses?

[Bill Huber]

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.

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That sure makes it clear and easy to see.

Thanks for the work...

[Bill Huber]

Wow, after years and years of reading about table saws I never even realized you had to check alignment at 45 as well as 90, I've learned something new today!

Bill just FYI, I was able to buy brass shim stock locally in a combo pack with different thicknesses. I bought it from a Remote control+Train hobby store. I think (not positive) that Hobby Lobby might have it as well. Sounds like you've ordered yours already, but posting this for anyone else needing shim stock.

I have a bunch of shim stock, brass sheets 6"x12" and from .001 tp .015 so I should be in good shape.
The problem now is just getting the shims in, I think Jet made the saw and said lets make it as hard as we can for someone to adjust it....:rolleyes:

[Andrew Hughes]

Steve that gif is killer.
This thread should be saved for its the best explanation Ive read and seen yet.

[ian maybury]

Hi Bill. I'm coming in late, but have an especial interest in the issue having been through it myself when setting my Hammer K3 panel saw up. It was miles off out of of the factory. OK in the vertical, but burning cuts badly with the blade tilted to 45 deg.

Several have probably explained it already - hopefully this just confirms what has been said.

Getting in as you say can be a bitch, and is saw specific. I had to make a special tool to access the required nuts, and support the trunning assembly when they were loose. The factory i'm sure builds this stuff up on a bench with the underside of the table upwards and before the table is assembled on to the cabinet. They as a result likely have no such access issue during production - it's a pity they don't bloody well do it right then.

Step by step as i experienced it:

The saw blade in order to cut at angles off vertical has to tilt.

This tilting is permitted by the mounting of the saw spindle in a casting which incorporates semi cicrcular trunnions at each end. (large area bearings - as under many band saws) More budget saws may just use horizontally placed pivot pins to form a hinge, but the principle is the same.

While it slides in the strunnions to tilt, the tilting actually takes place around an axis or line running close to parallel to the line of the plane of the blade - actually passing through the centres of the two semi-circles described by the two trunnion bearing surfaces.

It's relatively simple to see that moving one or other end of the trunnion assembly/of this axis/line to the left or right (usually by use of shims placed vertically in the appropriate gap) adjusts the toe in/out when cutting vertically. (i too like to run with 0- 0.001 in toe out from the rip fence at the rear)

It turns out that shimming one or other end of this axis up or down vertically (by shimming the appropriate end of the trunnion trunnion assembly - it's usually mounted to the underside of the saw table, and the shims are placed horizontally between it and the table) changes the toe out setting when the blade is tilted.

Dropping the infeed end (shimming horizontally between the infeed end of the trunnion assembly and the table) of this axis will cause the rear end of the blade to toe out or move further away from the rip fence, and vice versa.

The very good news if you think it through is that (presuming no other movement) this has no effect on the previously completed toe out adjustment of the blade when its in the vertical.

The result is that it's normally possible (the exact procedure depends on the design of the trunnion assembly - especially on where it's convenient to place shims vertically and in manner that prevents them falling out) to as a first step set the toe out of the blade where you want it when it's in the vertical position. Then having tipped the balde to 45 deg (making sure this first/blade vertical adjustment is not lost) place a second lot of shims horizontally under whichever end of the trunnion as required to deliver the required toe out in that situation.

I've found that using a dial gauge equipped saw gauge like the Woodpeckers item works fine in both situations: http://www.incrementaltools.com/Woodpeckers_Saw_Gauge_p/wpsg-wp.htm

Brass shim stock works nicely. I used a spritz of spray contact adhesive to fix successive shims in place while working up to the correct settings - this prevents adjustments being lost and shims falling down inside the cabinet. Double sided tape might be considered an option, but i've found that it has significant thickness, and tends to compress over time.

The other consideration I'm sure you are well familiar with is that it can be important to set up the toe out by touching the saw gauge off the same marked tooth - rotating it 180 deg to check it in the infeed and outfeed positions. (the plate should be, but may or may not be running in precisely the same plane as the teeth)

This should be a one time adjustment. Once set up the toe out should remain the same for tilted and vertical cuts - so that future adjustments may be made in the normal way by adjusting the alignment of the rip fence.

[Bill Huber]

Well working with it for about 6 hours I gave it up for the day.
I have the blade at 90° still at .001 which is good I think, the problem is still at 45°.

I cannot get the shim under the back left bolt, I can get it under the right one and the center one but just can not get to that back left one. I even took the stand's cross brace off so I could get under the saw but just did not have the room to get my arm and hand to the place it needed to be.

I think what I am going to do is get a die grinder from a friend and cut a slot in the back of the saw. My Jet is the hybrid contractor and the back is closed. I could take the saw all apart and flip it over but I just don't want to do that. The slot will not hurt the saw, there is one in front so I see no problem with putting one in the back. With the slot I can then use needle nose pliers to get the shim under the bolt.

I did prove that the back needs to go down, I lowered the front and that made things a lot worse so that to me said the back needs to go down.

I really would like to thank everyone for their comments and input on the subject, it has all helped.

[Jerry Miner]

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.

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Steve-- Excellent graphic!! You ARE da man!

[Brian W Smith]

I'd look at cosine error in the measurement process,get that under control and then move twds seeing what range the motion is and where manufacturing,screwed up(ha)........but,have been wrong before?