# What Tolerances For Fence Alignment??



## Jerry Bowen (Jun 25, 2011)

Had a reason to take my Incra LS TS off of the rails today. I had removed the stops recently that I had previously been used to return the base to a position which put the fence back into alignment.

I decided to see how close I could get the fence aligned with the miter slots using the dial indicator that I use to align the blade. I had to quit working on the job due to time restrictions and will get back to it tomorrow. But so far I still have about .012" error to deal with.

The question of course has to do with what other members feel about this subject, and how close do they align there fenced on there table saw's with their miter slots?

Jerry


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## MAFoElffen (Jun 8, 2012)

For my Rockwell I have a 36" square piece of 3/4" key stock that I put into the miter slot, then check the fence against it. Sort of a no-brainer to that. 

The panel saw, there is no miter slots (per say). I measure the distance from the static table to the sliding table, front and back... then if there is err, I err to having the back of the slider out within 0.002" at 30" back from blade. The arbor is set dead on with the static table edge and the table is pinned to the frame. The fence has been set steady at 0.001" from the static table edge. You have to remember... that is a 1300 pound saw. The fence rail is probably about 80 pounds... and the "L" square for the fence weighs more.

But that rip fence is set different than American saws. The fence is on a solid, thick machined round bar that has 4 mounting studs attached in it. You adjust that bar to the table (via pairs of nuts on those mounting studs) to adjust that. The fence "L" square is a cast iron casting that is machined and goes over that rod. Not really any way for it to get bumped and be out of adjustment. It can be flipped over forward to the front to be out of the way of the table surface. It takes some work to get squared, but it keeps those settings very well and for a very long time. Although relative and not _necessary_, I like to keep that saw level. Makes setups on that easier and faster.

Most people settle on within 0.2mm or about 0.008" on the rip fence. I just figure if I can get that closer, then I'll have a lot more time before I have to do that again. But I also do a quick preflight check on it before I use it each day (longer periods between this winter).


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## Jerry Bowen (Jun 25, 2011)

MAFoElffen said:


> For my Rockwell I have a 36" square piece of 3/4" key stock that I put into the miter slot, then check the fence against it. Sort of a no-brainer to that.
> 
> The panel saw, there is no miter slots (per say). I measure the distance from the static table to the sliding table, front and back... then if there is err, I err to having the back of the slider out within 0.002" at 30" back from blade. The arbor is set dead on with the static table edge and the table is pinned to the frame. The fence has been set steady at 0.001" from the static table edge. You have to remember... that is a 1300 pound saw. The fence rail is probably about 80 pounds... and the "L" square for the fence weighs more.
> 
> ...




Mike,
That saw of yours intrigues me. You have mentioned several really great features about it from time to time. 

Thanks for your information about the .008" fact. Sometimes I get more into the set up of my tools and their performance than I do with using them on a project. Right now, I'm into just setting my saw up as best I can after installing the second LS system on it. In so doing I created a empty space between the router table and the left edge of the table of the saw, it is about nine inches wide, I filled it with a piece of MDF. Then there was another blank or empty space to the right of the table of about 17" to the end of the rails where the base of the Incra LS is positioned. I have filled it with another piece of MDF. 

Up until I added the second LS to the set up I had a set of stops on the rails so that when I moved the base of the LS to the router table and then returned it to its original position, when the base hit the stops, the fence was back in a square postion. Now that I won't be moving the TS fence any longer I don't need those stops to be to the right of the base. Now I can position them to the left edge of the base. This way, if I ever need to remove the base for any reason, when I put it back on the rails it will be positioned again so that the fence is still square. This arrangement gives me a couple of extra inches available between the fence and the blade as those stops no longe occupy that area at the end of the rails.

I do like what you said about giving the saw a test flight each day to be certain that all is still as it should be. Things are constantly moving and it's just a good idea to take precautions. Thanks fo causing me to think about it.

I wonder if you have noticed that when your fence is set for a certain cross cut that the result will be different when ripping. I'm referring the width of the cuts. There probably is a difference also just by going from one species of wood to another. Consequently constent checking is just a good idea when final diminutions are important. The importance of such things vary with the projects one is working on. I am led to belief that it also varies between the way different people think about such things. Anyway, as I said earlier, I am sure intrigued with that great saw that you have.

Jerry


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## david_de (Jun 3, 2013)

Jerry Bowen said:


> . Anyway, as I said earlier, I am sure intrigued with that great saw that you have.
> 
> Jerry


Mike's new saw is really something. I had a chance to eyeball it a while back. More than a little envious. It is like he is driving a Maserati. When I got back home my Model T (saw) did not look so bright and sparkly. It was really a treat to see what is available out there and to be close enough to touch it. No worries I am not crazy enough to touch it. Well maybe, but only if Mike was not looking. ;-)


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## MikeMa (Jul 27, 2006)

The rip fence on my TS is set so it very slightly (a few thousandths of an inch) splays out from the blade. This does nothing to the accuracy of the fence or the saw, but it goes a long way in reducing burning on the work piece, and doesn't bog the blade down as much.


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## DesertRatTom (Jul 3, 2012)

Good discussion. I keep my fence splayed out slightly from a 3/4 length in the right hand miter slot. Doing this stopped burning and I know it reduces chances of kickback.


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## Jerry Bowen (Jun 25, 2011)

I continued to work on the alignment of the fence this morning. I had the metal plate that is part of the magnetic feather board installed on the Incra fence and could not get the fence aligned to my satisfaction. I removed the metal plate and got the Incra fence to have an error of only .001" from front to back. Then reinstalled the metal plate, the error was then about .012" with the plate installed. Guess that I'll have to live with that because I do like the magnetic feather board to be used with the MJ splitter. Then when ripping a board I use a long stick and after getting the workpiece well into the blade, maybe about a third of the way, I stand way to the left and reach over with the stick and feed the board on through the cut. I have been "broke to lead" as the saying goes in regard to the danger of a kick back. I'm scared to death of them after learning about them the hard way. I only have experienced a bad kick back when trying to rip a short narrow piece, never had one on a normal long rip, but I'm not going to take any chance. I'm straying from the main subject of the this post, sooo.. let's get back to it.

With the fence aligned it was time to calibrate the primary scale again. Before starting on the calibration I checked to see if the blade was still 90 degrees to the table top. I used the Wixly angle gauge and tweaked the tilt until the guage read 90.0. Once that was done I started to calibrate the primary scale on the carriage of the LS system. 

This time I tried a new approach. I set the scale on the carriage to one and a half inches and then used a piece of scrap ash that was about 24" long 3/4" thick and two inchs wide. I then fed the board into the blade end wise, not a cross cut, for about three inches, brought it back and took the board to the band saw and cut off the left edge of the cut leaving the part that I needed to measure and determine how far off the setting of the scale was, and made a correction. 

I repeated this until the primary scale and the actual cut matched thus the primary scale was properly calibrated. 

Next I checked the angle of the blade again using a different approach. After making my cuts that were required to calibrate the scale I laid the board on the table top and measured the width of the board with the calipers laying flat on the table. Once that reading was observed, I flipped the board over so that the face that had been down on the table was now up and measured the other face which was then down. The measurements were slightly off and again I tweaked the blade until these two readings matched. Then I checked the calibration of the primary scale on the carriage one more time and was within 
.004". I cannot get any closer than that and as been pointed out to me by more knowledgeable members of this forum, working with wood just can't be any closer than that so I have quit for now.

The next test will be to see how close the set up remains to be correct after a few days and some use. 

Jerry


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## MAFoElffen (Jun 8, 2012)

Jerry--

Do you have one of those magnetic bases for your dial indicator? One of the one's that has a switch to lock it down? Or maybe a mag-lock switch?

If you do, measure how much it is off. Put a brass feeler gauge of that measurement against the end of the fence that is out. Then lock down the magnetic base down to your table, while against that feeler gauge (feeler gauge sandwiched between the two.) Remove the feeler gauge. Then adjust the fence to that locked down base.

Otherwise, unreferenced, without a landmark, you are probably overshooting that adjustment unintentionally. Just seems simpler to do things with a landmark to reference from.

If you don't have something like that, you could always clamp a block down to the table.

I'm no doctor, but with it now being out 0.015", you are out an additional 0.003" further than what you started with in your first post in this thread? You started your adjustments because you were out 0.013". That is what cause you to say "that" was too much and the reason for adjusting it, right? Just wondering... 

You were asking about my fences, mentioning rips/crosscuts and such.

My Rip fences extrusions are 36" long, quick change units (large t-slot). One that is the same European design as Altendorfs, Felders, Martins. etc... like the Delta Unisaw fence extrusions (high/Low). Another is a Uni-T-Fence extrusion.

I have a lot of Crosscut fence extrusions, varying from 2' to 6' that mount to my 5' by 15" wide sliding table. I have table extensions that extend the width to around 5' wide. So my measurements on fences are much further out to keep my accuracy. The adjustments at 6' make the off-by-foot negligible. They pivot for miter cuts and I have positive stop miter stops (also adjustable) for cutting miters and then the 90 degree fence return stops.

Remember me saying that even with my Rockwell that 80% of my cuts are left of the blade. Most of that was with sleds and that crosscut fence I built for the Rockwell (2 miter bars rode in the 2 left miter slots). Even easier to do that with that sliding table and it's crosscut fences.

We think of Rip and Crosscut from different perspectives. 

First there is in the main reference referring to blades and grain direction. Veneered panels have directional grain of the veneered skins. Manufactured panels are not as directional. I can rip on the slider without touching the rip fence (straightening and joining cuts). Some of my true crosscuts are 5 foot long cuts. 

In the other lessor meaning is about technique. Basically, technique wise, I could break that down to if I'm using the rip fence -or- one or more of the crosscut fences. Other techniques are if I'm using neither a rip nor crosscut fence-- such as with a rip stop and clamps, just clamps... Or with multiple fences cross-cut (using the rip fence pulled forward to use as a material stop/reference... like a thin-strip jig, but on a larger scale); or with multiple fences (multiple crosscut fences or a crosscut fence used with a palin fence). 

So to make the difference in rip technique and crosscut technique, a simple question would break that down to it's most basic element-- Is the saved work piece (that material is being cut off of) left or right of the blade? If you break that down even further... A cut is just a cut... and you can overthink things if you make them into something more difficult than they really need to be.

I just like to make things with my hands... where sawdust is a byproduct. Tools just help me do that.


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## Jerry Bowen (Jun 25, 2011)

MAFoElffen said:


> Jerry--
> 
> Do you have one of those magnetic bases for your dial indicator? One of the one's that has a switch to lock it down? Or maybe a mag-lock switch?
> 
> ...





Mike,
first of all, my dial indicator is the one that I bought from Woodpecker that rides in the miter slots with medal rods for the base of the indicator to ride in. No magnets in this set up.

I'm repeating myself, but due to the fact that I can get the primary Incra fence down to an error of .001" obviously tells me that the error is on the metal plate. I ran out of time to continue to mess with it, but I'm suspecting that the problem lies in the way the the place is attached to the primary fence. As you may or may not know, the plate is attached to the Incra fence with a screw at each end that extends through the plate into a rectangular nut that ride in a slot in the Incra fence.

Right now I'm thinking the problem might be as simple as the screw being just a little to long and is allowing me to pull the plate tight against the fence. That is going to be the first thing that I check when I get back to the shop, right now I'm tied up with some yard work that can't be put off.

The sequence of what I have been doing sort of bears out what I suspect of. I tried to square the fence to start with, with the plate installed, got to that original error, then took the plate off, and got the good results with the primary fence by itself. Then reinstalled the plate and got a differenct reading, suggesting that the error might be as decribed above. The fact that the error is a constant increase from one end to the other implies this possibility. In other words there is is not a bow in the plate. 

As you describe your "high end" saw that we all drool over it, I have to admit that I am way behind the curve in understanding all of what you describe. You, and your beautiful saw, are just way out of my league, at least for the time. But I like to try to follow you and admire your know how about what you are doing. Keep the info coming. Sure wish I could observe what you are doing with it.

Jerry


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## MAFoElffen (Jun 8, 2012)

Jerry Bowen said:


> Mike,
> first of all, my dial indicator is the one that I bought from Woodpecker that rides in the miter slots with medal rods for the base of the indicator to ride in. No magnets in this set up.
> 
> I'm repeating myself, but due to the fact that I can get the primary Incra fence down to an error of .001" obviously tells me that the error is on the metal plate. I ran out of time to continue to mess with it, but I'm suspecting that the problem lies in the way the the place is attached to the primary fence. As you may or may not know, the plate is attached to the Incra fence with a screw at each end that extends through the plate into a rectangular nut that ride in a slot in the Incra fence.
> ...


K. Yes, I see. That doesn't set well for doing fine adjustments then.

Sorry. I guess I should do pic's, diagrams or video to explain setups and fences. Not really detailed or difficult. Just a lot of moving parts and pieces, that leave room for adaptable and flexible setups.

But the basic techniques were somewhat the same as I used with my Rockwell. Just less struggle and more accurate with this one. This one makes things simpler. And I like simple.


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## JIMMIEM (Apr 4, 2010)

*Table Saw Fence Alignment*



Jerry Bowen said:


> Had a reason to take my Incra LS TS off of the rails today. I had removed the stops recently that I had previously been used to return the base to a position which put the fence back into alignment.
> 
> I decided to see how close I could get the fence aligned with the miter slots using the dial indicator that I use to align the blade. I had to quit working on the job due to time restrictions and will get back to it tomorrow. But so far I still have about .012" error to deal with.
> 
> ...


I had read that a ts with the fence aligned within .003", the thickness of a human hair, is considered well aligned. I got my saw aligned to .001".


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