TS Alignment- Master Plate or not?

[Greg Muller]

All,

You have all given me some good advice before (other than a few who need to use a mask around those vapors when finishing ), so I am calling on your collective genius once again.

I am moving most of my larger iron into my new shop, and had to dismantle my Jet tablesaw for the transfer. I am going to take advantage of this by trying to set it back up as accurately as is practical- practical being the key word here.

I am sure some of you have tried the Master Plate -http://www.amazon.com/MasterGage-MP-...2698605&sr=1-1

should I invest in one of these, or is using a saw blade good enough for "practical" accuracy?

Either way, I do plan on using a dial gauge, etc...

Thanks for the advice,

Greg

[Bruce Wrenn]

For less than $20, buy John White's book "Care and Repair of Shop Machines." He show how to use a HF dial indicator and a couple of scraps to make a jig that will do what the Master Plate does. This is one of my favorite books.

[Billy Reynolds]

I just completed a tune up on my Jet saw a couple of days ago and opted for the master plate. Seem to obtain better repeatability than using a blade.

[Lance Norris]

I have the Master Plate and Superbar. I recommend both.

[Eric Haycraft]

I am going to go against the grain here. If you have any measurable runout on the arbor, the plate becomes useless and using a good quality blade will be much more accurate. You simply pick one tooth on the blade, mark it with a marker and use that to make your adjustments. Obviously a gauge block is required, but I feel that the plate isn't worthwhile.

Eric

[Greg Muller]

Eric,

correct me if I'm wrong here (which I am frequently), but isn't having the MasterPlate supposed to help you to discover if you have runout or not? If found, then I can correct it and move on to the rest of the measurements.

Greg

[Gary Keedwell]

I am going to go against the grain here. If you have any measurable runout on the arbor, the plate becomes useless and using a good quality blade will be much more accurate. You simply pick one tooth on the blade, mark it with a marker and use that to make your adjustments. Obviously a gauge block is required, but I feel that the plate isn't worthwhile.

Eric

I think were mixing apples and oranges here. The plate is to measure the runout of the flange which the blade rests on. A flange that is not perpendicular to the the arbor and table will cause a wobble in the blade.
Gary

[Eric Haycraft]

I believe that the main goal of the plate is to adjust the blade parallel to the slot. If you have arbor runout (my saw does) the only way to make this adjustment is to have an object that rotates with the arbor (a blade typically) to check the parallelism. When I check mine, I put a dot on a tooth and check that tooth at the front, rotate the blade via the belt and check that same tooth at the back. There is no way to do this rotation with the plate, so unless you have zero runout at the arbor, you won't end up with an accurate result.

my $.02

[Dave Falkenstein]

Eric,

correct me if I'm wrong here (which I am frequently), but isn't having the MasterPlate supposed to help you to discover if you have runout or not? If found, then I can correct it and move on to the rest of the measurements.

Greg

I don't see how a flat plate is going to measure runout. Checking for runout is a seperate test, done by rotating the arbor itself. A MasterPlate and a saw blade are both supposedly flat. Using either will allow you to set the blade parallel to the miter slot. I use a saw blade myself.

The photo in Billy's post shows a TS-Aligner, in addition to the MasterPlate. I use the TS-Aligner, Jr and I think it is worth the one-time expense. It is easy to use, accurate and works in a variety of setup and measurement applications in the shop.

http://www.ts-aligner.com/tsalignerjr.htm

[Tom Henderson2]

I am going to go against the grain here. If you have any measurable runout on the arbor, the plate becomes useless and using a good quality blade will be much more accurate. You simply pick one tooth on the blade, mark it with a marker and use that to make your adjustments. Obviously a gauge block is required, but I feel that the plate isn't worthwhile.

Eric

Hi Eric-

I agree with your point that a Master Plate is not a cure-all. But I don't agree that using the one-spot-on-the-blade technique eliminates arbor FLANGE runout from the data.

At any location, you will measure the sum of arbor flange runout and blade runout.

Using a blade, and rotating it so that both the fore- and aft-readings are taken from the same spot DOES eliminate the BLADE runout from the data.

But the influence of FLANGE runout will still be in the data. If you remount the blade with the arbor turned 90 degrees, you will get different results than you did initially even if you use a blade as described above.

So using the one-tooth-on-the-blade method and the master plate should give you the same results.

The plate is smoother, and it is a bit easier to use since you don't have to spin the blade. And the plate can be turned so that the long dimention is up, and that makes for easier angle setups.

But you need to account for arbor flange wobble regardless of which method you use, either by finding the arbor angles that give the min- and max- wobble and setting the plate/blade up at the midpoint, or the best way which is fixing the arbor itself.

I'll bet your saw has negligible arbor flange wobble, in which case your method of aligning to one spot on the blade WILL give you the best alignment. But if the arbor is wobbly, you need to account for it.

My $0.02

-Tom Henderson
Ventura, CA

-Tom H.
Ventura, CA

[Eric Haycraft]

Hi Eric-

Using a blade, and rotating it so that both the fore- and aft-readings are taken from the same spot DOES eliminate the BLADE runout from the data.

But the influence of FLANGE runout will still be in the data. If you remount the blade with the arbor turned 90 degrees, you will get different results than you did initially even if you use a blade as described above.

The point of rotating the blade is to cancel out both the blade's runout and the plate/blade's runout at the same time. This rotation is the only way to cancel out both and why I suggest that you need to use the same tooth and rotate the blade. Since you can't rotate the plate without remounting it, there is no way to cancel out the arbor runout with the plate. If you don't rotate the arbor when making these adjustments, you will not be parallel to the slot when there is any arbor runout..period..no matter how flat the surface (blade or plate) is that you use to make your adjustments.
If there is runout in the arbor, the plate will amplify the runout and cause a misalignment. That's why you need something that can be rotated with the arbor - because the measurement needs to be made in relation to the same spot on the arbor. You can mount a piece of wood or steel bar, but it is just as simple and accurate to use a blade to dial the table into alignment.

[Greg Muller]

Again, you guys are pointing out issues that I had not even considered.

I thought that you could rotate the MasterPlate just like a blade.
That would prove more useful. Are you guys sure that you can't?

Billy and Lance- you guys own one- it won't rotate like a blade?


I assumed that it would work identical to a blade except that it would guarantee flatness.

Greg

[Billy Reynolds]

I only posted the picture to show the plate in use. The first step I used in my tune-up was to use the TS Aligner to check for arbor runout. Had I detected a arbor runout problem......I would have been looking at correcting the problem before proceeding with the tune-up. May I suggest if you use the blade or plate for alignment with a arbor runout problem.......you still have a problem.......I would be looking seriously at the arbor bearings. My .02 worth. Maybe we are getting away from the purpose of the original post. The picture does not depict a test for arbor runout but plate (blade) being parallel with miter slot. Greg the plate can not be rotated 360 degrees.

[Dave Falkenstein]

...I thought that you could rotate the MasterPlate just like a blade.
...Greg

Simply look at the photo in Billy's post. There is so way to rotate the MasterPlate, if it is mounted with the long dimension parallel to the saw top. Mounted the other way, you could rotate it some, but doubtfully enough to use the same spot on the plate to take a reading with the dial gauge.

First things first. As previously mentioned, the arbor must be tested first for runout. If there is arbor runout, the blade will not run true, period. The arbor runout issue must be resolved first. The good news is that most saws have no appreciable arbor runout.

One thing about using the blade and rotating it - you must be certain you do not push on the blade, deflecting it while rotating it. It is surprisingly easy to deflect the blade a few thousandths, making the reading incorrect.

[Greg Muller]

Simply look at the photo in Billy's post. There is so way to rotate the MasterPlate, if it is mounted with the long dimension parallel to the saw top.

Dave,
I looked at the photo previously. The Master Plate is only 10" long (same as a blade even if the diagonal measurment would be longer)- I thought maybe the pic was taken using a TS with a short opening. My Jet has a 13" opening. I supposed that with the extra length available it could still be rotated.

Greg