Table saw alignment, cant get it quite right

[Chris Harry]

A few weeks ago, I had a kickback incident with my Ridgid R4511 (granite top) table saw. Because of it I decided to check the alignment of everything.

The blade is .003 out of parallel with the left most miter slot. Arbor has 0 runout. Fence was toed away from the rear of the blade in comparison to the front (so it shouldnt have pinched the material)

Today I decided to tackle the .003 (really? .003?) and for some reason I just cant get it any closer. I really didnt want to deal with re-aligning the whole top, so I stuck with leaving the right front tight as the pivot point, loosened the other 3 corners and then was tapping on the left rear, to move the back of the table closer to the blade.

Anytime I got closer than .003, as I tightened down the left rear (where I was tapping to move it) it went back to .003 after fully tight. I could literally watch the dial gauge move even from hand tightening.

I tried tightening that bolt last, first, in a pattern with the other 2, etc. I tried to overshoot the .003 so when tightened it would come in line with 0, but I could never get it closer than .001 or so and tightening it led it back to .003.

So Im still at .003 out....and now Im wondering, should I just leave it?

If I try to rip 3/4" red oak hardwood (which is when I had the kickback), it takes a lot of effort to feed through. 3/8" plywood breezes right through the blade no matter what. The blade is a WWII that hasnt seen very much work at all (and I just cleaned it with LA Awesome Yellow)

Thanks in advance.

-Chris

[Jeffrey Fluharty]

Hi Chris. I'm new here, but been working wood for close to 40 years. My first thought is the red oak. Maybe enough internal stress in the wood to cause it to pinch the blade a little? The reason I say that is because you said plywood was breezing right through. And it would be really rare to see plywood behave like normal wood. Second, I'm sure your rip fence is really straight? No chance there's any twist, or bow in it that would cause the wood to change its relationship with the fence as it's pushed through? Seems unlikely since again, you said you didn't have any problems with the plywood. .003 just doesn't seem to be enough to cause serious problems like you're experiencing. Anyway, just a couple thoughts. Good luck with your problem.

[Lee Schierer]

I had this problem with my Craftsman saw and discovered that the lock washer was pulling the carriage back to the slots that the lock washer had cut into the carriage. By rotating the lock washer so the teeth weren't in those slots I could tighten the bolt without it moving.

[glenn bradley]

As mentioned, wood moves. Stress release can make things bind even on a well tuned saw. That's why we all run splitters or riving knives. Even with those all-important safety items I'm sure more than one of us has had material so lively it actually grabs the splitter and stalls or tries to take it along for the ride.

This sounds like a saw with table mounted trunnions. As always I will recommend PALs for this format of a saw. It was the best $25 I ever spent when I had a contractor saw. PALs not only make fine adjustments easy on table mounted trunnions but, they hod the setting while you torque things down.

You are probably doing this but, I will mention that you want to align the blade and the fence to the same miter slot. This should automatically align them to each other. I use the left slot since that is where I primarily run my miter gauge.

Here's some parts I was ripping from a piece of square-milled mahogany.

b-GnG-BC-1-stress-released.jpg

Obviously this kind of release would cause trouble no matter how well aligned the saw. they won a trip to the burn pile and I made new parts out of another section of the same board without issue.

[Art Mann]

0.003" is not very significant. The way you push the wood through the blade will have a greater effect than that. If you are having trouble riping 3/4" red oak with a 1.5 - 1.75 horsepower saw, then you are in a multitude of good company. If you haven't done so already, try using a thin kerf rip blade rather than a general purpose blade. It makes a huge difference.

Edit: If we are talking about the root cause of a kick back, I agree with those who said you may be relieving internal stresses in the wood, which causes it to warp and twist.

[David Delo]

Chris,

I have the same saw. Here's some thoughts:

1.) I think some guys enlarged the hole (very slightly) in the frame to get around what you describe.
2.) Thin kerf works better on this saw. Are you using the stock riving knife? I switched mine out.
3.) For me, .003 should be okay but that's absolutely the most I'd ever let it get to. I'm under .002
4.) I was having burning and hard push through issues until I ditched the 2 piece stock fence. Put a Delta T2 fence on it and haven't looked back since. It's made the saw a real winner in my book and does what I need it to do.
5.) Are you using the same blade to rip oak and cut plywood? I don't have a Forrest blade but I do use (I forget) either a 80 or 100 tooth blade for plywood and would never touch plywood with my Freud rip or cross-cut blades.

Stay safe,
Dave

[Mort Stevens]

Sounds like that left rear bolt/hole/washer has something (casting flash or surface defect) that keeps pulling it back into the same place.

If you're intent on getting closer than 0.003" then try it by leaving the left rear bolt tight and make that the pivot point and loosen the other three bolts holding the top, and by 'loose' I mean still pretty tight , just loose enough that you need a good whack to move the top. Get the top in alignment and tighten the bolts about a 1/4 turn (may need more/less not fully tight, but make them tighter, just not all the way yet), then check/adjust one last time, tighten bolts a little more, check alignment and then finally tighten the bolts down. With the bolts sufficiently tight you can easily make adjustment as small as 0.0005" (or less) with a little experience and not get any unwanted movement during the final tightening.

[Dennis Aspö]

I can't give any advice on how to fix the alignment but even if it where perfect, I would put a short fence over the regular fence for ripping natural timber, so that the fence ends around the middle of the blade.

[Chris Harry]

First off, thanks for all the replies. VERY helpful information and gives me a bunch of things to try/look at.

Im not sure why I got a full kerf blade forever ago....I thought I read the saw could handle it, and maybe it can, but Im guessing the full kerf will "amplify" any alignment issues with a lower-power saw. Ill be ordering a thin kerf Fusion to use in case I send the WWII out for sharpening.

Its interesting that enlarging the frame hole was mentioned....I then Googled for THAT and found a bunch of hits. And one person even said the large washer on the bolts inside the frame were hitting the side of the frame and preventing movement. Sure enough, I looked at the rear right bolt on mine and the washer is VERY close to the frame right now. Could very well be why the table wouldnt move anymore. Im going to try removing the washer completely (as a test) to see if I can get it aligned better.

Im using the splitter(s) from the Steel City version of this saw. Ordered them from Woodcraft forever ago. Im not sure they will work with a thin kerf blade, so I might have to go back to stock depending on the thickness of the Fusion.

Every measurement I took on the fence was good. I pushed a square down the length of the fence and never saw any gaps at the top or bottom (not sure if thats the best indication for twisted or bowed....any better way of checking it?) The fence is an Incra TS Ultra, so it should be better than stock. Ive pondered getting rid of it for a T2 but other than space Im not sure what the T2 would gain me.

Again, thanks for all the great info. Im going to have at it again tonight and am hopeful these tips will help.

[Lee Schierer]

Im not sure why I got a full kerf blade forever ago....I thought I read the saw could handle it, and maybe it can, but Im guessing the full kerf will "amplify" any alignment issues with a lower-power saw. Ill be ordering a thin kerf Fusion to use in case I send the WWII out for sharpening.

Okay, A Woodworker II is a very good combination blade, but it isn't ideal for ripping. It is a 40 tooth blade and with a lower Hp saw a 24-30 tooth ripping blade even full kerf type will work much better. I have a Craftsman 1-1/2 Hp saw and can easily rip 5/4 Oak and Maple with my 30 tooth Freud glue line rip blade. When ripping, you want to insure that the bottoms of the gullets are a bit (1/8=1/4") above the top surface of the wood. This does several things. It allows the gullets to clear out the chips, which are more like shavings when ripping, and it helps exert some downward pressure on your wood that helps prevent it from lifting off the table.

Poorly cured wood, can bow and twist when ripped. I've seen boards that were straight and flat bow significantly when ripped. This bowing can push the wood into the blade producing kick back. You also need to push the piece between the fence and the blade completely through the cut and clear of the blade. Never push the piece that is free to the left of the blade to make the cut. And don't put a regular feather board behind the leading edge of the blade. I use Grip Tite feather boards and have never had a kick back when using them. They are mounted as you can see below when ripping. The one behind the blade has a grit covered roller that not only holds the wood down, but is biased to pull it toward the fence.
lsfence1.jpg

[Chris Harry]

Thanks again everyone.

Got home from work and went right to the saw (much to the chagrin of the wife )

Pulled that right rear bolt out completely, just barely loosened the left side bolts (leaving the front right as the pivot). Sure enough, a few decent taps and all of a sudden I was within 0.001. Ground down the washer for the bolt I removed completely and reinstalled it. Even after tightening and "losing" some accuracy from that left rear bolt, I ended up at 15 thousandths. So yeah, improved AND good enough.

Now tackling the 45 degree dimensions. Its not HORRIBLE (10 thousandths farther from miter at rear of blade than front) but I see there are already a bunch of shims in the front of the table where I would need to add even more to fix the alignment.

Question for anyone that has dealt with it before - should i be adding even more shims? Im just worried Ill end up somehow putting tension on the granite causing it to crack. I dont need to add much per calculations I found on the web (.0245 front right, .032 front left) but I somehow wonder if I would be better off starting from scratch. I cant remember when I got the saw if I ended up with the shims back in their stock locations after removing the table top to bring the saw indoors.

Thanks in advance....almost there!

-Chris

[Lee Schierer]

Sure enough, a few decent taps and all of a sudden I was within 0.001. Ground down the washer for the bolt I removed completely and reinstalled it. Even after tightening and "losing" some accuracy from that left rear bolt, I ended up at 15 thousandths. So yeah, improved AND good enough.

-Chris

I'm confused, or perhaps you are. You had the saw within 1 one thousandth (.001) and after grinding the washer and tightening it went to 15 thousandths (.015"). Hopefully you actually measured .0015 which would be 15 ten thousandths or 1.5 thousandths.

[Chris Harry]

I'm confused, or perhaps you are. You had the saw within 1 one thousandth (.001) and after grinding the washer and tightening it went to 15 thousandths (.015"). Hopefully you actually measured .0015 which would be 15 ten thousandths or 1.5 thousandths.

You are correct, I mistyped it. Should have put .0015.

[Chris Merriam]

Having only recently learned about the 45 degree alignment, I could be wrong here. But on my new Sawstop, the manual says that the 45 degree alignment will throw off the 90 degree alignment, so you have to chase your tail a few times to get them both in line. Not sure if that will apply to you or not.

[Chris Harry]

Having only recently learned about the 45 degree alignment, I could be wrong here. But on my new Sawstop, the manual says that the 45 degree alignment will throw off the 90 degree alignment, so you have to chase your tail a few times to get them both in line. Not sure if that will apply to you or not.

Yeah I was assuming that will happen....but I wanted to be sure there was a way I could get the 90 close to begin with, otherwise Id be fighting the 45 AND the 90. Now that I know the 90 can get within very acceptable range, I should always be able to get back to that number or better even after mucking with the 45.

Ive never done any bevel cuts on my table saw (for bevel crosscuts I just use my compound miter), where I figure the 45 would make a difference, but Id rather have it close once and be done with it.