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
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.
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
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?
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!!!
Go here: http://www.newwoodworker.com/dilindjiguse.html
for some more answers.
Also, there is a link for mounting the dial indicator in the miter slot. I
used something similar till I got a TSAligner Jr.
As others mentioned, http://www.ts-aligner.com/ is about the easiest to use,
and that one tool, with some simple additions, works for the TS, BS, jointer,
DP, router table, etc. The only items I've added are a straight edge, feeler
guage, and a precision 45/90. For a good TS fixture, you might take a close
look at what he did. That thickness variation sounds normal to me, as it's the
teeth that count here.
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.
Looks like you got a bunch of good replies! I thought I would add my
1. You looking to put your dial indicator on a stick. For low cost,
simplicity, and ease of use you can't beat this:
1A. 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.
2. 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
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.
Home of the TS-Aligner
Mike W. wrote:
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
Thanks for the advice.
Charlie Self told me a quick and CHEAP way to align my TS blade. Here
1. Screw a board (I used a one foot section of tubafore) to your miter
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.
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
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 <.006 over 13", takes
only a few seconds, and is accurate enough for most uses. I have a dial
indicator-based setup that'll do much better, but takes much longer, so I
don't use it unless needed.
On 23 Mar 2005 20:24:13 -0800, email@example.com wrote:
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.
Home of the TS-Aligner!
PS: Ask Charlie where he put his money!
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
But then Ed wouldn't make any bux....
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.
Home of the TS-Aligner!
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"
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.
Home of the TS-Aligner!
I think you guys have missed a couple of things I said so I'll explain
in more detail.
Aligning a tablesaw doesn't involve figuring out which feeler gage fits
into a single gap and which does not. There are two gaps and the goal
is to make them equal. So, the objective is to find one feeler gage
that fits the same in both gaps.
In addition, I said the blade is flexible. It acts like a spring. As
you apply force to a spring, resistance starts at zero and rapidly
increases to a specific level. The resistance stays at that fixed
level over a certain distance of movement. Then the resistance
increases exponentially. Translated: as you push your feeler gage into
the both gaps, the force could "feel" the same but the actual distance
might not be. The trick to obtaining accurate results with feeler
gages is to stay out of that range of motion where the force is
constant. You can do this with your "go/no-go" technique. But, that
isn't going to be practical in the 0.001" range unless you have a
feeler gage set with 0.001" increments and your reference has nice,
square, crisp edges. A sloppy reference with rounded edges and angled
ends will steer you into the constant force range of the springy blade.
As I said, some people are pretty good at it. I'm not. And, to be
honest with you, I have no interest in developing skills for subjective
methods when an objective instrument (dial indicator) is faster,
easier, more reliable, and cheaper. Yes, cheaper! Investing in a
trustworthy set of feeler gages (not the $2.00 el-cheapo spark plug set
at the local auto parts store) and a decent ground steel reference will
cost many times more than a reliable dial indicator. What I really
don't understand is why some people have such a fear of dial indicators
that they will spend so much time and money to avoid them and then go
out of their way to dissuade others from using them too.
Home of the TS-Aligner!
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