Question on tabel saw specs

[Al Piccolo]

Hello, I am new to the forum. I have been just lurking and learning...lots of good information to be found here.

I have a new Jet Deluxe Exacta with 30 inch fence that I am having a problem with. If I align the saw blade and the right miter slot with the blade fully extended I can get it right on the money. If I then lower the blade to about 1 inch above the table and check the alignment, it is now off by10/1000 (to the left). Is this normal? Jet says it is within spec.

One other thing I have done is to set the blade to 90 (verified with an Incra square) and then put a Wixey digital angle gauge on the blade, zero it and lower the blade. By the time I get to the bottom of the blade travel, the Wixey is fkickering between .1 and .2. Jet says this is also normal.

Any thoughts or ideas?

Thanks

[Barry Vabeach]

Al, on the second issue, I don't think it is a problem. The Wixey works by first determining level, and then measuring off that. If there is any flex in the way your saw is mounted, you can get .001 to .002 change in reading just by that movement. I have the great lakes casters, and even with the mounting pads lowered, I get that much rock in the table to see that variation in the readout. Even if your table saw is dead solid to the ground, you can easily get enough flex in the blade itself to be off .01. I can't imagine tha being off that little on a 1 inch high cut would be significant. On the first issue, I am confused by your math - are you saying .001 or .010 "? If you download the Sawstop manual for the industrial cabinet saw, go to page 50 on Balde Elevation assembly. They say that the issue is how the blade elevation assembly is set in relation to vertical. They say that most saws have some lateral movement , and there is an adjustment for that on their saw, though not many others have that adjustment. Their spec is .002. Unless you are noticing a real problem, I would just set the adjustment of the blade to the miter slot at the height you use it most ( in my case about 1 1/2" above the table) and not worry about it.

[glenn bradley]

DAMHIKT. Is your saw standing level? That is, (at least) when placing a level on the top behind the blade running left to right is it level? And is it also level when measuring left to right in front of the blade? I level my saw between all four corners prior to aligning. As my saw is stationary, it stays that way. If you move your saw about, at least it gets a solid baseline setup, eh? As always, rip cut quality at 90* and 45* pretty much override anything else. If your good, your good.

[Al Piccolo]

Thanks for the replies. On the level issue, no, the saw does not sit level. I have it on a Jet heavy duty mobile base and the garage floor does have a slight slope to it.

On my first issue, Here is what I am doing: I mark a tooth at the front of the saw, place my dial indicator on the mark and zero it out. I then rotate the blade so the marked tooth is at the rear od the saw and slide my align-it tool down the miter slot to the marked tooth in the rear. This results in a measurment of +.002 with the blade fully extended.

Next I lower so that about 1.25 inches are exposed. I rotate the blade so that the marked tooth is at the front of the saw. This measurment is now +.023. Now I rotate the marked tooth to the rear and the measurment is +.012. If I make the same measurments I did above, except this time I zero out the dial indicator on the front tooth, the difference front to back is now -.011 which agrees with the measurments taken without zeroing out the dial indicator. I only did the measurments without zeroing out the dial indicator to show that the blade looses it's paraellism to the miter slot as it is lowered.

I hope this makes sense.

[Cliff Holmes]

Al,

First, try measuring the body of the blade, not the tooth. See if you get a different answer.

Second, make absolutely sure that your DI is securely mounted. Try making the same measurements from both miter slots, they may not show the same front-to-back variance but should show the same top to bottom change.

Finally, if all the measurements agree and the blade really does kick over 1/100 (.01) and not 1/1000 (.001) then I'd call Jet and tell them there's no way this is "in spec". 1/100 is a HUGE amount to be out of alignment. If I had paid $2500 for a saw, I'd damn sure want it more "Xact" than that.

[Howard Acheson]

The observations you relate leads me to think that your trunnion is out of alignment. There is a specific process to go through to check or re-align it. Jet should be able to send you the instructions if they are not in your instruction manual.

BTW, align your blade and fence with the miter slot you normally use.

[Lee Schierer]

Repeat your measurements by lowering the blade and then raising it back up the same number of turns it was lowered and see if your reading returns to zero or stays off.1 or .2.

When working with a dial indicator, always repeat the measurement back to the starting point to insure that the operator didn't introduce any error into the measurement.

[Al Piccolo]

Well, I have double checked all my measuments and still came up with the same thing.

One thing I should add is that I have had the saw in for repair for this issue. The repair shop was stumped. They kept the saw for two months and said they replaced "the bottom half of the saw" and made sure everything was aligned properly.

I have tried all the suggestions I could find and still get the same results.

One thing I also tried was to raise the blade, put my DI in the center bottom of the blade and then lower the blade. This produced a measurment of .028 by the time the blade was lowered all the way. Jet claims that a blade is not a good reference point, and I agree, but I have installed the blade backwards, and took the readings again with the same result. Jet said that if I could do this with something like a MasterPlate and still got the same results, they would "talk" about it. So, I have spent another $50 to try to prove there is something wrong with my saw.

Does anybody have a Jet saw, that they could measure as I have described ?

Thanks.

[Bill Huber]

Well, I have double checked all my measuments and still came up with the same thing.

One thing I should add is that I have had the saw in for repair for this issue. The repair shop was stumped. They kept the saw for two months and said they replaced "the bottom half of the saw" and made sure everything was aligned properly.

I have tried all the suggestions I could find and still get the same results.

One thing I also tried was to raise the blade, put my DI in the center bottom of the blade and then lower the blade. This produced a measurment of .028 by the time the blade was lowered all the way. Jet claims that a blade is not a good reference point, and I agree, but I have installed the blade backwards, and took the readings again with the same result. Jet said that if I could do this with something like a MasterPlate and still got the same results, they would "talk" about it. So, I have spent another $50 to try to prove there is something wrong with my saw.

Does anybody have a Jet saw, that they could measure as I have described ?

Thanks.

Not sure if this is what you want.

I have a Jet contractor saw that is about a year old.

I put the Mater Plate pn making sure everything was clean and free of dust.
Raised the blade up, not to the stop but has high as I could without hitting the stop. Took a reading, lowered the blade and watched the DI as I lowered it, no change.

The pictures tell the story, I was very happy to see it.



125752 125753

125754

[Al Piccolo]

Thanks for checking Bill, that is what I was looking for. I have a MaterPlate on order. It should be here next week. I am not holding out much hope that the MasterPlate is going to show me anything different, but I have to go through this exercise to convince Jet there is a problem.

At least now I know that what my saw is doing is not normal and they can't use the old line "they all do it"

[Barry Vabeach]

Al, maybe I am not understanding this right, but if you do the measurement from the right miterslot as you lower the blade, turn the blade 180 degrees and repeat, and repeat the same two measurements from the left miterslot, haven't you eliminated any real problem with the blade not being flat. I admit I am having trouble with the spatial concepts, but have you ruled out the possibility that you are not setting the blade to a true 90 ( I know you used an Incra square) Have you used another method to verify it is at a true 90
such as cutting a peice of tall straight stock using the right miter slot, then trimming of a peice from the left side and measuring the offcut with a dial caliper at the top and bottom to see if measurements are different. Altenatively, set the blade angle so that you get no movement on the dial indicator when you raise or lower the blade, then raise the blade to its heighest level and trim a piece of stock and check it with the Incra to see if the cut is plumb. Good luck

[Al Piccolo]

Al, maybe I am not understanding this right, but if you do the measurement from the right miterslot as you lower the blade, turn the blade 180 degrees and repeat, and repeat the same two measurements from the left miterslot, haven't you eliminated any real problem with the blade not being flat. I admit I am having trouble with the spatial concepts, but have you ruled out the possibility that you are not setting the blade to a true 90 ( I know you used an Incra square) Have you used another method to verify it is at a true 90
such as cutting a peice of tall straight stock using the right miter slot, then trimming of a peice from the left side and measuring the offcut with a dial caliper at the top and bottom to see if measurements are different. Altenatively, set the blade angle so that you get no movement on the dial indicator when you raise or lower the blade, then raise the blade to its heighest level and trim a piece of stock and check it with the Incra to see if the cut is plumb. Good luck

Barry, No matter which miter slot I use, which way the blade is intalled, or which position I rotate the blade to, the result is always the same to within .002, the blade movement as I lower it is always to the right.

I have used a cheap combo square, my Incra square, and my Wixey digital angle gauge to set the blade square, but the issue still remains. Even if I set the blade to any angle between 90 and 45, the top of the blade still moves the same distance to the right as I lower the blade.

I have told Jet all of this, but they saw that a saw blade is not a good reference to use. That is why I am getting the MasterPlate...they can't argue with that.

Thanks

[Tom Veatch]

Al, if the blade arbor axis of rotation isn't dead on parallel to the axis of rotation of the blade elevating mechanism, you'll see the effect you are describing. If that's the case, you will also see a slight change in tilt angle as well as miter angle when the blade elevation is changed.

I don't know if there are any adjustments the owner can make to correct that misalignment. If there are, they would have to be made in the trunnion, itself. There's no adjustment in the normal TS alignment process that will correct that kind of error.

Since all manufactured items are built to some tolerances, very few items will be exactly nominal, but all should fall within some specified tolerance band. Apparently Jet is saying that your's is within that specification. My personal opinion is, assuming good measurement equipment and techniques, what you're reporting seems to be a little too sloppy for the presumed quality of the Xacta table saw.

I do not see that effect in my Jet Xacta 10XL.

[Barry Vabeach]

Al, I feel for you. Not that they will pay for it, but if you get the plate and they agree it is a problem with the saw, you should ask them to pay for the plate too. While I agree that a saw blade is not perfectly flat, I can't think of how it can possibly be out of true in 2 different directions at the same time. You might want to ask for a supervisor. I can understand that they want to make sure it isn't some dumb mistake by the customer ( and I have done that) but it seems like you have tripled checked everything.

[johnny means]

These types of measurements are ridiculous on woodworking equipment. Stop wasting time and cut some wood.:)

[Tom Veatch]

These types of measurements are ridiculous on woodworking equipment. Stop wasting time and cut some wood.:)

It's true that we often wind up trying to chase down that last elusive thousandth of an inch when setting up our tools, forgetting that the material we work with is far from being dimensionally stable, and wind up chasing our tails more than anything else.

It's doubtful that .01 misalignment in the miter angle of the blade will be detrimental to the dimensional accuracy of a cut. However, when my TS is that far from "perfect" alignment, I can detect, by sound and feel, a definite effect as the workpiece clears the blade at the end of the cut as well as a greater tendency to burn the workpiece. When I start seeing those effects, it's time to interrupt the workflow and check and adjust alignment as needed.

Does it improve the quality of my completed projects? Not so's you'd notice, but I'm happier and more content when I can say my TS is aligned within .002. And the bottom line is; that's why I'm in this hobby, for happiness and contentment. It sure ain't for the money!

One poster recommended to the OP, and I agree with that recommendation, to align the blade at the approximate midpoint of the elevation travel, about 1.5" of blade exposure. That's the procedure I follow. It minimizes the maximum misalignment at points between the elevation limits and should result in a perfectly usable, functional saw.

There will always be some variation in miter and tilt angles with changes in blade elevation since the "perfect" trunnion has yet to be manufactured, but the values reported by the OP are more than what I would consider "normal".