TS Setup/alignment questions

[Mike W.]

I was messing around with my relatively new and unused dial indicator today to verify alignment of my table saw and came up with a few questions. I DAGS and got some answers to my questions, but was wanting to see if anyone could give me some more direct answers to the questions below.

Here are the questions.

1) I have the Grizzly Dial indicator. I haven't figured out a good way to mount it to the miter guage or any other fixture to use it for checking the blade alignment vs the miter slot. What I have done so far is to clamp the big bulky assmebly that comes with it to the miter guage and to it that way... but that puts the indicator at an awkward angle that is hard to read... and you can't get it closer than about a half inch to the table. Anyone have any pictures as to how they mount their dial indicator to something for checking alignment? I'm hoping to not have to go buy a tool specifically for checking alignment. I planned on building a jig for it, but figured I'd check here to see if anyone can show me one that they built first.

2) When testing the blade alignment, tooth at front vs same tooth at back I get just over .001" out of line which is good enough for me. But, if I slide the guage along the blade the measuer varies in a range a little over .002". Is that normal for a sawblade to have that much variation in thickness or do you think it is the miter slot? I have a Forrest WWII that cuts great, FWIW.

Thanks, Mike W.

[Doug Miller]

I can't help you too much with the first part... I use one of these:

Probably the blade. My Forrest WWII is slightly thicker at the center than it is at the edges; since the difference appears uniform, I assume it's intentional.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[Leon]

What counts is the measurement at the tooth. Many blades differ in thickness at different points.

[TDUP]

Make a wooden runner for your table slot and attach another 90 degrees to the top of the runner with a screw in the end. Touch the blade with the screw and then mark the tooth. Put the same tooth to the back and see if the screw touches the blade in that position. If it does, it's good to go. If not adjust accordingly. The no cost method!!!

[Darrell Dorsey]

[GerryG]

[Mike W.]

Exactly what I needed! Thanks!

Mike W.

[cmyers]

I don't have pictures, but might be able to explain it. I recently borrowed a Grizzly dial indicator with a magnetic base from a friend, and found the same issue in using it to measure parallelism of the blade to the miter slot. Forget about the magnetic base & the other rods that came with as far as this measurement is concerned; just attach the indicator to a board and clamp it to your miter guage. A little more detail:

I used a simple board (maybe 3/4" x 2" x 10" - the exact mearurements aren't critical) and drilled a hole near one end of it (from one 3/4" face through to the other 3/4" face). Through this hole you slide a

1/4" bolt (long enough to reach through the 2" of board with enough excess to slide through the hole on the dial indicator). Slide the dial indicator onto the bolt, add a washer & hex nut. Tighten the nut and you have the jig that I used.

Clamp this to your miter guage with the dial indicator pointing toward the blade. Basically it should appear as though you're intending to crosscut the piece of wood that your indicator is attached to. It's only as accurate as your miter guage, but I found it to be accurate enough to get me some smooth cuts.

-cm

[ejb]

Hi Mike,

Looks like you got a bunch of good replies! I thought I would add my $0.02.

1. You looking to put your dial indicator on a stick. For low cost, simplicity, and ease of use you can't beat this:

Yes, getting close to the table surface is important. You've already seen the problem with tilting the indicator. You could make (or buy) an Offset Bar like I put on my products.

1. Blade bodies are not always flat. They can be deliberately hollow ground, or they can be warped or cupped. What you are seeing is very typical.

Measuring on the surface of a carbide tooth is not necessarily the best solution for two reasons:

a. Placing a hardened chrome steel stylus tip against carbide can cause micro-chips and cracks. Yes, you can be careful but why even risk it?

b. Carbide teeth are ground with a relief angle so getting consistent readings can be difficult. You can easily convince yourself that you have the exact same reading but in reality you are just measuring in a slightly different location on the side of the tooth.

It's better to draw a dot on the blade body and take your measurements with the stylus on that dot (rotating the blade as necessary).

Hope it helps! Let me know if you have any questions.

Ed Bennett [e-mail]

of the TS-Aligner

Mike W. wrote:

checking the

little over

[Mike W.]

Thanks... you're right, that price can't be beat! I guess I was trying to make a simple problem more complex than it needs to be. When thinking in .001" it didnt really dawn on me that a screw and a board would suffice.

After looking at the comparison of the TS Aligner vs the 'Stick' I can see it's value.

Thanks for the advice. Mike W.

[phildcrowNOSPAM]

Charlie Self told me a quick and CHEAP way to align my TS blade. Here goes:

1. Screw a board (I used a one foot section of tubafore) to your miter gauge.
2. Mark a tooth on the blade (I used a piece of masking tape).
3. Put the miter gauge in the slot and raise the blade all the way up.
4. Screw a screw partway into the end of the 2x4 so that it just touches the tooth you marked on the blade on the front side.
5. Move the miter gauge to the back side and rotate the blade so that your same tooth (the one you marked with tape) is right there next to the screw. If it drags or doesn't touch, you need to adjust the table.

I'm sure your $150 table saw alignment tool is good for other stuff too, but I got within .001" with a wood scrap and 3 drywall screws. I ain't saying, I'm just saying.

-Phil Crow

[GerryG]

If done carefully, what you described is just fine. However, we're playing with imaginary number here. Most setups even with a dial indicator do not repeat to that tolerance without precision mechanical aids. Nor could you easily get that repeatability with a miter gauge. Not to mention that you gave your miter slot more precision than most machinest's squares.

Still and all, a carefully made jig, which shows repetition in repeated measurements, is easily enough for this adjustment. Note the emphasis on repetition, as I've seen many people never check it, and it doesn't matter if you can measure to .001 if several repetitions give several times that variation.

With a little thought and some careful work, you could also make a 45 deg reference that's accurate enough for many applications. The same holds for adjusting the fence parallel or slightly out from the miter slot.

It's just a question of what accuracy you need for any specific task, and how much time you want to invest. For instance, I use a calibrated extended pointer for the RAS when swinging the arm. It gives me ain't saying, I'm just saying.

[ejb]

Hi Phil,

Yep, this is what I call a traditional "feel the rub" or "hear the scrape" method. It does work and some people are pretty darn good at it. Personally, I find it to be pretty frustrating and tedius because it's very subjective. Which end rubs (or scrapes) more than the other? Back and forth over and over until you think you're convinced that it's right. I prefer to just look at the dial on an indicator and see exactly what is going on without any doubt or question. For me, nothing can beat an objective reading on a dial indicator. And, since one can easily be put on a stick for less than $20, it's hard for me to justify spending a bunch of time on a subjective method. But, I value my time differently than others. You might decide that saving $20 is well worth the investment in time.

Thanks, Ed Bennett [e-mail]

of the TS-Aligner!

PS: Ask Charlie where he put his m> Charlie Self told me a quick and CHEAP way to align my TS blade. Here > goes: >

[George]

Or, you could buy $1.99 worth of "objectivity" in the form of a set of feeler gages. Then you could write to the rec, and tell how far(close) you were instead of correcting what did poor work and leaving what did good alone.

But then Ed wouldn't make any bux....

[ejb]

Hi George,

I think "feeler" gages are very appropriately named! If you've ever tried them, then you know exactly what I mean. You literally have to "feel" how tight the fit is. Is it tighter on one end than the other? In my book, that's still pretty darn subjective, especially when you are trying to judge the gap between a big thin flexible steel plate (the blade) and some fixed reference (that tubafore/drywall screw or combination square, etc.). But, I can see how some people might think it's more objective.

On the other topic, I don't make any "bux" by recommending that someone go out and buy a cheap indicator and attach it to a stick. But, that's what I recommended. And, I still think that it has great advantages over the traditional "feel the rub" or "hear the scrape" methods - with or without "feeler" gages. You are more than welcome to disagree.

Ed Bennett [e-mail]

of the TS-Aligner!

George wrote:

far(close) you

[George]

Nope. Go/no go and difference.

You went to a different school, I can tell.

[phildcrowNOSPAM]

Ed,

Everything you said makes sense. BTW, I know I got within .001" because I used, ahem, a dial indicator that I purchased later. I don't own a purpose-built TS alignment tool, but I have found that the ol' magnetic base dial indicator to be a valuable tool.

On a separate note, I have a link here that has proven invaluable as far as tablesaw tune-up.

it helps somebody, anyway.

-Phil Crow

[ejb]

Hi again George,

I'd really be interested in finding out your source for such feeler gage sets. You say that you get "go/no-go and difference" capabilities for tablesaw alignment (less than 0.005" accuracy) from a set which costs less than $2.00. Of course, this isn't remotely realistic if you use the "tubafore" as your reference. But, for arguments sake, we'll assume that a nicer reference with square, crisp edges won't cost you any money (but honestly you know it will).

To be even remotely as effective as the cheapest dial indicator, you would need a feeler gage set with increments of 0.001". I confess, I could not find such a set for less than $2.00. Maybe you could share your source with everyone here? As I peruse my sources for feeler gages I found a really super cheap set which might do it for $5.00. That same source sells a cheap indicator for $8.50. I think I would still opt for the dial indicator! The extra $3.50 is money well spent in my opinion!

The school I went to isn't all that "different" from other schools. They still teach science and engineering, just like most other technological universities. And, after 22 years of "post graduate work" (i.e. real-life experience), I'd have to say that they did a fine job. I suppose it would have been a "different" school if they taught students to avoid precision measurement instruments (like dial indicators) in favor of more primitive methods of measurement (like feeler gages). Yes, that really would have been a very "different" school! ;-)

All kidding aside, using feeler gages is a valid method. And, some people are very good at obtaining accurate results with feeler gages. I'm not one of those people. I don't have the skill to subjectively discern the subtle differences. I really don't believe the "go/no-go" claim because it doesn't fit my experience. When I slide a feeler gage between two objects, I get three possible outcomes: "absolutely no resistance", "slight to high resistance", and "no fit". This middle category is the key to accurate measurement with feeler gages and the primary source of my frustration. If I am comparing two measurements which both fall somewhere in the middle category ("slight to high resistance"), then I can't make a good judgement - especially when one of the objects is flexible (like a saw blade). And, if I can't do it to my own satisfaction, then I can't recommend it to others.

Thanks, Ed Bennett [e-mail]

of the TS-Aligner!

George wrote:

[ejb]

Thanks Phil,

Yep, there's nothing like a dial indicator to give you that added sense of confidence!

Yes, I've seen Steve's stuff. Just don't get too carried away! I'll say no more. You might also find this pretty handy:

finally got the Jr. video on the web site. If you have a high speed connection then you can get a personal demonstration of tablesaw (and various other machinery) alignment. It's heavy on the "what" but, since every machine is different, it's a bit light on the "how". Someday I'll get deeper into the "how". Comments/questions always welcome.

Ed Bennett [e-mail]

of the TS-Aligner!

[bridger]

yes, it's subjective. but it is easy to feel the difference between two feeler guages that are .001 apart. this is adequate precision for many applications, including tablesaws.

and these days decent dial indicators can be had for about the price of a hotdog and a coke at a baseball game. indicators are lots of fun to play with....