Let me know what you guys think.

I've been working on a new method (new?) for checking the squareness of a square using a dial indicator. The method works in theory. I've tried it and it seems to work in practice. A caveat is that the square needs a thick edge to support a stylus.

I am going to work on a video demonstrating the process.

http://www.garagewoodworks.com/square_a_square.php

Thoughts?

In article ,
wrote:

Let me know what you guys think.

I've been working on a new method (new?) for checking the squareness of a
square using a dial indicator. The method works in theory. I've tried it
and it seems to work in practice. A caveat is that the square needs a thick
edge to support a stylus.

I am going to work on a video demonstrating the process.

http://www.garagewoodworks.com/square_a_square.php

Thoughts?

Seems totally unnecessary. A pencil and a straight edge (a la sheet
good cutoff) is all you need to check if it's actually square. And it's
fast to set up.

--
Outside of a dog, a book is man's best friend. Inside a dog, it's too dark to
read. - Groucho Marx

On Thursday, January 3, 2013 6:24:52 PM UTC-5, Dave Balderstone wrote:
In article ,

wrote:



Let me know what you guys think.



I've been working on a new method (new?) for checking the squareness of a

square using a dial indicator. The method works in theory. I've tried it

and it seems to work in practice. A caveat is that the square needs a thick

edge to support a stylus.



I am going to work on a video demonstrating the process.



http://www.garagewoodworks.com/square_a_square.php



Thoughts?



Seems totally unnecessary. A pencil and a straight edge (a la sheet

good cutoff) is all you need to check if it's actually square. And it's

fast to set up.

read the article.


A minor caveat to this method is that it can be difficult to discern small gaps between the two pencil lines (especially with a thick pencil lead).. The most you might be able to detect is a 0.010" difference which equates to a minimum detection of 0.036 degrees with an 8" square.
Another caveat is that the edge you place your square against must be perfectly flat, otherwise you will not get an accurate calculation of your square's angle error.


The dial indicator method is 10X more accurate.




--

Outside of a dog, a book is man's best friend. Inside a dog, it's too dark to

read. - Groucho Marx

On 1/3/13 5:30 PM, wrote:
A minor caveat to this method is that it can be difficult to discern
small gaps between the two pencil lines (especially with a thick
pencil lead).

Use a knife.


The most you might be able to detect is a 0.010"
difference which equates to a minimum detection of 0.036 degrees with
an 8" square. Another caveat is that the edge you place your square
against must be perfectly flat, otherwise you will not get an
accurate calculation of your square's angle error.


The dial indicator method is 10X more accurate.


Great, if we need to send a rocket into space, but not necessary for
woodworking. :-)

--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On Thursday, January 3, 2013 6:57:37 PM UTC-5, -MIKE- wrote:
On 1/3/13 5:30 PM, wrote:

A minor caveat to this method is that it can be difficult to discern

small gaps between the two pencil lines (especially with a thick

pencil lead).



Use a knife.





The most you might be able to detect is a 0.010"

difference which equates to a minimum detection of 0.036 degrees with

an 8" square. Another caveat is that the edge you place your square

against must be perfectly flat, otherwise you will not get an

accurate calculation of your square's angle error.





The dial indicator method is 10X more accurate.





Great, if we need to send a rocket into space, but not necessary for

woodworking. :-)

I like to have at least one master square that I know is balls to wall accurate. I had no way of checking before and I do now. The Draw-A-Line and flip method will never tell you how far out of wack your square is - only that it might be out of wack. There is no way to quantitate the angle error unless you can measure the distance betwene the lines/knife marks with a caliper (good luck). How much of a gap in between the marks is considered unacceptable? You can't easily answer that question so why bother checking in the first place?





--



-MIKE-



"Playing is not something I do at night, it's my function in life"

--Elvin Jones (1927-2004)

--

http://mikedrums.com



---remove "DOT" ^^^^ to reply

On 1/3/13 6:21 PM, wrote:
On Thursday, January 3, 2013 6:57:37 PM UTC-5, -MIKE- wrote:
On 1/3/13 5:30 PM, wrote:

A minor caveat to this method is that it can be difficult to
discern

small gaps between the two pencil lines (especially with a thick

pencil lead).



Use a knife.





The most you might be able to detect is a 0.010"

difference which equates to a minimum detection of 0.036 degrees
with

an 8" square. Another caveat is that the edge you place your
square

against must be perfectly flat, otherwise you will not get an

accurate calculation of your square's angle error.





The dial indicator method is 10X more accurate.





Great, if we need to send a rocket into space, but not necessary
for

woodworking. :-)

I like to have at least one master square that I know is balls to
wall accurate. I had no way of checking before and I do now. The
Draw-A-Line and flip method will never tell you how far out of wack
your square is - only that it might be out of wack. There is no way
to quantitate the angle error unless you can measure the distance
betwene the lines/knife marks with a caliper (good luck). How much
of a gap in between the marks is considered unacceptable? You can't
easily answer that question so why bother checking in the first
place?


Yeah, ok man... good luck with those rocket ships. :-)


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

On 1/3/2013 6:21 PM, wrote:
....

I like to have at least one master square that I know is balls to
wall accurate. I had no way of checking before and I do now. The
Draw-A-Line and flip method will never tell you how far out of wack
your square is - only that it might be out of wack. There is no way
to quantitate theangle error ...

What difference does it make what the numeric value is?

If it's enough to detect that way, it's enough that for really precise
layouts it's off.

So, what you gonna' do at that point, anyway even if you do know
_precisely_ how much that is? Eggs-ackly the same thing as if you only
know it's off---either ignore it and go on, go get a new Starrett, or
adjust it until it does pass (the peen method works a charm for that).

If it passes the pencil test, it's plenty close enough for woodworking;
even fine woodworking. The wood itself moves more than that.

--

wrote in news:bc9297af-00ce-44cd-8f63-cfff2cea2c50
@googlegroups.com:


I like to have at least one master square that I know is balls to wall accurate. I had no way
of checking before and I do now. The Draw-A-Line and flip method will never tell you how
far out of wack your square is

Pfui. Of course it will. The more the lines diverge, the more out of whack it is.

- only that it might be out of wack. There is no way to quantitate the angle error unless you
can measure the distance betwene the lines/knife marks with a caliper (good luck).

That'll work. Feeler gauges will probably work better.

How much of a gap in between the marks is considered unacceptable? You can't easily
answer that question so why bother checking in the first place?

Of course you can easily answer that question. Decide what percentage error is
acceptable in your project, and you can easily calculate the permissible gap between the
marks. Suppose you want accuracy to one part in 1000 (99.9%). The gap between the
pencil lines at a distance of 8" -- double the error in the square, remember -- must be no
more than 8 * 2/1000 = 0.016", which is easily measurable with feeler gauges, a dial caliper,
or a mike.

wrote in message
...

On Thursday, January 3, 2013 6:57:37 PM UTC-5, -MIKE- wrote:
On 1/3/13 5:30 PM, wrote:

A minor caveat to this method is that it can be difficult to discern

small gaps between the two pencil lines (especially with a thick

pencil lead).



Use a knife.





The most you might be able to detect is a 0.010"

difference which equates to a minimum detection of 0.036 degrees with

an 8" square. Another caveat is that the edge you place your square

against must be perfectly flat, otherwise you will not get an

accurate calculation of your square's angle error.





The dial indicator method is 10X more accurate.





Great, if we need to send a rocket into space, but not necessary for

woodworking. :-)

I like to have at least one master square that I know is balls to wall
accurate. I had no way of checking before and I do now. The Draw-A-Line
and flip method will never tell you how far out of wack your square is -
only that it might be out of wack. There is no way to quantitate the angle
error unless you can measure the distance betwene the lines/knife marks with
a caliper (good luck). How much of a gap in between the marks is considered
unacceptable? You can't easily answer that question so why bother checking
in the first place?
================================================== ================================================== ================================================
There are a number of ways to measure that gap. With the tools that I know
you have, a drill press, a dial indicator, a piece of chewing gum (pre
chewed) and a pin will allow you to measure to .002 or less.





--



-MIKE-



"Playing is not something I do at night, it's my function in life"

--Elvin Jones (1927-2004)

--

http://mikedrums.com



---remove "DOT" ^^^^ to reply

On Jan 3, 7:21*pm, wrote:
On Thursday, January 3, 2013 6:57:37 PM UTC-5, -MIKE- wrote:
On 1/3/13 5:30 PM, wrote:

A minor caveat to this method is that it can be difficult to discern

small gaps between the two pencil lines (especially with a thick

pencil lead).

Use a knife.

*The most you might be able to detect is a 0.010"

difference which equates to a minimum detection of 0.036 degrees with

an 8" square. Another caveat is that the edge you place your square

against must be perfectly flat, otherwise you will not get an

accurate calculation of your square's angle error.

The dial indicator method is 10X more accurate.

Great, if we need to send a rocket into space, but not necessary for

woodworking. *:-)

I like to have at least one master square that I know is balls to wall accurate. *I had no way of checking before and I do now. *The Draw-A-Line and flip method will never tell you how far out of wack your square is - only that it might be out of wack. *There is no way to quantitate the angle error unless you can measure the distance betwene the lines/knife marks with a caliper (good luck). *How much of a gap in between the marks is considered unacceptable? *You can't easily answer that question so why bother checking in the first place?

4x dollar store reading glasses.

In article ,
wrote:

read the article.

Did.

--
Outside of a dog, a book is man's best friend. Inside a dog, it's too dark to
read. - Groucho Marx

In article ,
wrote:
On Thursday, January 3, 2013 6:24:52 PM UTC-5, Dave Balderstone wrote:
In article ,
wrote:
Let me know what you guys think.
I've been working on a new method (new?) for checking the squareness of a
square using a dial indicator. The method works in theory. I've tried it
and it seems to work in practice. A caveat is that the square needs a thick
edge to support a stylus.
I am going to work on a video demonstrating the process.
http://www.garagewoodworks.com/square_a_square.php
Thoughts?
Seems totally unnecessary. A pencil and a straight edge (a la sheet
good cutoff) is all you need to check if it's actually square. And it's
fast to set up.
read the article.
A minor caveat to this method is that it can be difficult to discern
small gaps between the two pencil lines (especially with a thick pencil
lead). The most you might be able to detect is a 0.010" difference which
equates to a minimum detection of 0.036 degrees with an 8" square.
Another caveat is that the edge you place your square against must
be perfectly flat, otherwise you will not get an accurate calculation of
your square's angle error.
The dial indicator method is 10X more accurate.

What are we building here, bookcases or space shuttles? 10X more accurate
is not necessary for woodworking.


--
Make it as simple as possible, but not simpler. (Albert Einstein)

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

On Thursday, January 3, 2013 8:41:23 PM UTC-5, Larry W wrote:
In article ,

wrote:

On Thursday, January 3, 2013 6:24:52 PM UTC-5, Dave Balderstone wrote:

In article ,

wrote:

Let me know what you guys think.

I've been working on a new method (new?) for checking the squareness of a

square using a dial indicator. The method works in theory. I've tried it

and it seems to work in practice. A caveat is that the square needs a thick

edge to support a stylus.

I am going to work on a video demonstrating the process.

http://www.garagewoodworks.com/square_a_square.php

Thoughts?

Seems totally unnecessary. A pencil and a straight edge (a la sheet

good cutoff) is all you need to check if it's actually square. And it's

fast to set up.

read the article.

A minor caveat to this method is that it can be difficult to discern

small gaps between the two pencil lines (especially with a thick pencil

lead). The most you might be able to detect is a 0.010" difference which

equates to a minimum detection of 0.036 degrees with an 8" square.

Another caveat is that the edge you place your square against must

be perfectly flat, otherwise you will not get an accurate calculation of

your square's angle error.

The dial indicator method is 10X more accurate.



What are we building here, bookcases or space shuttles? 10X more accurate

is not necessary for woodworking.


Scenario: You make it out to the woodshop after a hard night of drinking. As the acetaldehyde takes it's effect on you, you drop your Starrett square on the concrete floor. What do you do? Continue to use it and hope for the best or check to see if it's still of 'Starrett Quality'? How do you check?







--

Make it as simple as possible, but not simpler. (Albert Einstein)



Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

In article ,
wrote:
On Thursday, January 3, 2013 8:41:23 PM UTC-5, Larry W wrote:
What are we building here, bookcases or space shuttles? 10X more accurate
is not necessary for woodworking.

Scenario: You make it out to the woodshop after a hard night of
drinking. As the acetaldehyde takes it's effect on you, you drop your
Starrett square on the concrete floor. What do you do? Continue to use
it and hope for the best or check to see if it's still of 'Starrett
Quality'? How do you check?


I'm by no means a teetotaler, but I haven't had a "hard night of drinking"
in over 20 years. And if or when I did, I sure wouldn't head to the wood
shop afterwards. And if I did, I probably wouldn't use one of my Starret
squares. And if I did use the Starret, probaly wouldn't drop it. And if
I did happen to drop it, after a hard night of drinking, I probably
wouldn't care enough to check it.

What was the question again?



--
Make it as simple as possible, but not simpler. (Albert Einstein)

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

wrote in news:214a7bab-b962-477d-8340-
:

Scenario: You make it out to the woodshop after a hard night of drinking. As the
acetaldehyde takes it's effect on you, you drop your Starrett square on the concrete floor.

Doesn't happen in my shop. That's a hard and fast safety rule he if I drink, I stay out of the
shop until after a full night's sleep.

That doesn't mean I can't or won't ever drop the square, of course -- just means that if I do, it
will be the result of my own innate clumsiness, not of inebriation.

What do you do? Continue to use it and hope for the best or check to see if it's still of
'Starrett Quality'? How do you check?

Your imagination is lacking, Brian g. I can think of at least half a dozen things I could
check it against:
-- angle between the jointer fence and bed (previously set using the same Starrett square)
-- angle between the fence of the Incra 3000 miter gauge, and the miter bar (ditto)
-- angle between the Incra 3000 and the table saw blade (ditto)
-- one of my Jevons 3D squares http://www.jevonstoolco.com/ -- I have no connection
with the company, except as a *totally* satisfied customer -- these are great products, and
as close to dead-on-perfect as a woodworking tool needs to be (within 0.002" in 6",
according to the manufacturer)
-- my crosscut sled
-- any corner of at least seven pieces of furniture in my home that I've made using some or
all of the above

wrote:

Let me know what you guys think.
-----------------------------------------------------------
A slow night in the Carolinas.

Lew

On Thursday, January 3, 2013 10:19:46 PM UTC-5, Lew Hodgett wrote:
wrote:



Let me know what you guys think.

-----------------------------------------------------------

A slow night in the Carolinas.

Then go out and get a drink Lew! Get off yer butt!




Lew

On 1/3/2013 6:30 PM, wrote:
On Thursday, January 3, 2013 6:24:52 PM UTC-5, Dave Balderstone wrote:
In article ,

wrote:



Let me know what you guys think.



I've been working on a new method (new?) for checking the squareness of a

square using a dial indicator. The method works in theory. I've tried it

and it seems to work in practice. A caveat is that the square needs a thick

edge to support a stylus.



I am going to work on a video demonstrating the process.



http://www.garagewoodworks.com/square_a_square.php



Thoughts?



Seems totally unnecessary. A pencil and a straight edge (a la sheet

good cutoff) is all you need to check if it's actually square. And it's

fast to set up.

read the article.


A minor caveat to this method is that it can be difficult to discern small gaps between the two pencil lines (especially with a thick pencil lead). The most you might be able to detect is a 0.010" difference which equates to a minimum detection of 0.036 degrees with an 8" square.
Another caveat is that the edge you place your square against must be perfectly flat, otherwise you will not get an accurate calculation of your square's angle error.


The dial indicator method is 10X more accurate.




--

Outside of a dog, a book is man's best friend. Inside a dog, it's too dark to

read. - Groucho Marx

Then use a marking knife.

On Thursday, January 3, 2013 10:06:49 PM UTC-5, tiredofspam wrote:
On 1/3/2013 6:30 PM, wrote:

On Thursday, January 3, 2013 6:24:52 PM UTC-5, Dave Balderstone wrote:

In article ,



wrote:







Let me know what you guys think.







I've been working on a new method (new?) for checking the squareness of a



square using a dial indicator. The method works in theory. I've tried it



and it seems to work in practice. A caveat is that the square needs a thick



edge to support a stylus.







I am going to work on a video demonstrating the process.







http://www.garagewoodworks.com/square_a_square.php







Thoughts?







Seems totally unnecessary. A pencil and a straight edge (a la sheet



good cutoff) is all you need to check if it's actually square. And it's



fast to set up.



read the article.





A minor caveat to this method is that it can be difficult to discern small gaps between the two pencil lines (especially with a thick pencil lead). The most you might be able to detect is a 0.010" difference which equates to a minimum detection of 0.036 degrees with an 8" square.

Another caveat is that the edge you place your square against must be perfectly flat, otherwise you will not get an accurate calculation of your square's angle error.





The dial indicator method is 10X more accurate.









--



Outside of a dog, a book is man's best friend. Inside a dog, it's too dark to



read. - Groucho Marx



Then use a marking knife.

You're still left with not being able to quantitate the error. Are you following along?

wrote in news:ee116537-b047-4754-88e2-dfc87af63570
@googlegroups.com:

On Thursday, January 3, 2013 10:06:49 PM UTC-5, tiredofspam wrote:
Then use a marking knife.

You're still left with not being able to quantitate the error. Are you following along?

_Of course_ you can "quantitate" [sic] the error. What makes you think it can't be measured?

In article ,
wrote:

You're still left with not being able to quantitate the error. Are you
following along?

I've watched you go from presenting what you thought was a good idea to
spending an inordinate amount of energy insulting anyone who disagrees
with you.

There's a solution for this at my end, fortunately. I am implementing
it now.

--
"You couldn't get a clue during the clue mating season in a field full
of horny clues if you smeared your body with clue musk and did the
clue mating dance." -- Edward Flaherty

wrote in message
...

On Thursday, January 3, 2013 6:24:52 PM UTC-5, Dave Balderstone wrote:
In article ,

wrote:



Let me know what you guys think.



I've been working on a new method (new?) for checking the squareness of
a

square using a dial indicator. The method works in theory. I've tried
it

and it seems to work in practice. A caveat is that the square needs a
thick

edge to support a stylus.



I am going to work on a video demonstrating the process.



http://www.garagewoodworks.com/square_a_square.php



Thoughts?



Seems totally unnecessary. A pencil and a straight edge (a la sheet

good cutoff) is all you need to check if it's actually square. And it's

fast to set up.

read the article.


A minor caveat to this method is that it can be difficult to discern
small gaps between the two pencil lines (especially with a thick pencil
lead). The most you might be able to detect is a 0.010" difference which
equates to a minimum detection of 0.036 degrees with an 8" square.
Another caveat is that the edge you place your square against must be
perfectly flat, otherwise you will not get an accurate calculation of your
square's angle error.
================================================== ================================================== ================================================== ========
Use a knife to mark and do it on a flat smooth surface. MDF or. better yet,
a piece of metal covered in dykem blue. Make your line as light as possible.
Use magnifier. A discrepancy of .001 is readily visible.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
The dial indicator method is 10X more accurate
================================================== =========================================
Got a metal lathe? If you do, it can be used to make a master square that is
more accurate than anything you can buy for less than several hundred
dollars. Not needed though. Use the flip and mark
method.

On 1/3/13 5:24 PM, Dave Balderstone wrote:
In article ,
wrote:

Let me know what you guys think.

I've been working on a new method (new?) for checking the squareness of a
square using a dial indicator. The method works in theory. I've tried it
and it seems to work in practice. A caveat is that the square needs a thick
edge to support a stylus.

I am going to work on a video demonstrating the process.

http://www.garagewoodworks.com/square_a_square.php

Thoughts?

Seems totally unnecessary. A pencil and a straight edge (a la sheet
good cutoff) is all you need to check if it's actually square. And it's
fast to set up.


And plenty accurate enough for woodworking.
I used a utility blade to mark. Just a small mark near the corner of the
square and another at the top of its leg. No need to mark its entire
length.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply

wrote:
Let me know what you guys think.

I've been working on a new method (new?) for checking the squareness of a square using a dial indicator. The method works in theory. I've tried it and it seems to work in practice. A caveat is that the square needs a thick edge to support a stylus.

I am going to work on a video demonstrating the process.

http://www.garagewoodworks.com/square_a_square.php

Thoughts?

Sinced/dx (arctan) is close to 1 near 0, yourerror is not very big, but
your equation which divides an angle by L (before applying arctan)
doesn't make sense. For instance, it suggests that if you choose L
great enough that your error will be as small as you need it to be. I
did not try to redo your derivations, but I am willing to do so if we
don't find a concensus. By the way,you might sketch a triangle
somewhere(tan = opp/adj)for those that may be a bit rusty at doing trig.

Bill

On Thursday, January 3, 2013 7:24:24 PM UTC-5, Bill wrote:
wrote:

Let me know what you guys think.



I've been working on a new method (new?) for checking the squareness of a square using a dial indicator. The method works in theory. I've tried it and it seems to work in practice. A caveat is that the square needs a thick edge to support a stylus.



I am going to work on a video demonstrating the process.



http://www.garagewoodworks.com/square_a_square.php



Thoughts?



Sinced/dx (arctan) is close to 1 near 0, yourerror is not very big, but

your equation which divides an angle by L (before applying arctan)

doesn't make sense. For instance, it suggests that if you choose L

great enough that your error will be as small as you need it to be. I

did not try to redo your derivations, but I am willing to do so if we

don't find a concensus. By the way,you might sketch a triangle

somewhere(tan = opp/adj)for those that may be a bit rusty at doing trig.



Bill

Trust me, the math works. Draw a few squares that are off by a little in CAD and check.

Use my online calculator:
http://www.garagewoodworks.com/square_a_square_Math.php

wrote:
On Thursday, January 3, 2013 7:24:24 PM UTC-5, Bill wrote:
wrote:

Let me know what you guys think.
I've been working on a new method (new?) for checking the squareness of a square using a dial indicator. The method works in theory. I've tried it and it seems to work in practice. A caveat is that the square needs a thick edge to support a stylus.
I am going to work on a video demonstrating the process.
http://www.garagewoodworks.com/square_a_square.php
Thoughts?


Sinced/dx (arctan) is close to 1 near 0, yourerror is not very big, but

your equation which divides an angle by L (before applying arctan)

doesn't make sense. For instance, it suggests that if you choose L

great enough that your error will be as small as you need it to be. I

did not try to redo your derivations, but I am willing to do so if we

don't find a concensus. By the way,you might sketch a triangle

somewhere(tan = opp/adj)for those that may be a bit rusty at doing trig.



Bill
Trust me, the math works.
If you are going to present the math, then do so (properly).

The sentence tht you wrote: "The answer given will be the amount in
degrees that your square is off. "
is terrible. Squares are not "off", degrees are not measure in amounts,
and no answer was given (and no question was asked)!!

If you are going to get rigorous, then do so--let's not pawn it off.
"Trust Me, the math works", should not follow your (lack of a) a
successful derivation.
Lets not trip to slip the argument by people just because you figure
you've already worked hard enough on it! I enjoy well-done mathematics
as much as anybody, surely more than some. Hope to see you try again.

Bill


Draw a few squares that are off by a little in CAD and check.

Use my online calculator:
http://www.garagewoodworks.com/square_a_square_Math.php

On Thursday, January 3, 2013 8:04:12 PM UTC-5, Bill wrote:
wrote:

On Thursday, January 3, 2013 7:24:24 PM UTC-5, Bill wrote:

wrote:



Let me know what you guys think.

I've been working on a new method (new?) for checking the squareness of a square using a dial indicator. The method works in theory. I've tried it and it seems to work in practice. A caveat is that the square needs a thick edge to support a stylus.

I am going to work on a video demonstrating the process.

http://www.garagewoodworks.com/square_a_square.php

Thoughts?





Sinced/dx (arctan) is close to 1 near 0, yourerror is not very big, but



your equation which divides an angle by L (before applying arctan)



doesn't make sense. For instance, it suggests that if you choose L



great enough that your error will be as small as you need it to be. I



did not try to redo your derivations, but I am willing to do so if we



don't find a concensus. By the way,you might sketch a triangle



somewhere(tan = opp/adj)for those that may be a bit rusty at doing trig.







Bill

Trust me, the math works.

If you are going to present the math, then do so (properly).



The sentence tht you wrote: "The answer given will be the amount in

degrees that your square is off. "

is terrible. Squares are not "off", degrees are not measure in amounts,


and no answer was given (and no question was asked)!!

Squares can be "off" in the sense that they are not a true 90 degrees. Every square will be "off" to some degree. Perfection is imaginary.





If you are going to get rigorous, then do so--let's not pawn it off.

Reposted for your convenience:
"For the same angle error, as L get longer so does abs(Delta1 - Delta2). "


"Trust Me, the math works", should not follow your (lack of a) a

successful derivation.

Lets not trip to slip the argument by people just because you figure

you've already worked hard enough on it! I enjoy well-done mathematics

as much as anybody, surely more than some. Hope to see you try again.

There is no need to "try again" and I appreciate your veiled arrogance.

Where are you having trouble with the math?




Bill





Draw a few squares that are off by a little in CAD and check.



Use my online calculator:

http://www.garagewoodworks.com/square_a_square_Math.php

wrote:

There is no need to "try again"

Then who is being arrogant?

and I appreciate your veiled
arrogance.


Where are you having trouble with the math?

Your identifiers are poorly chosen making your "work" difficult to read.
From your words/diagram, it looks like delta1, delta2, and L are all
the same.
I don't see the 5-degrees you mentioned (in your diagram).

Doing math is like doing design: Do-over, and do-over, and do-over. One
should
get quite humble about the process!

Bill

wrote in news:5443d0e1-47e2-4bf4-9dc6-237d07bf6357
@googlegroups.com:

There is no need to "try again" and I appreciate your veiled arrogance.

Where are you having trouble with the math?

Ummm.... Brian, you don't know Bill personally. I do.

He's not the sort of guy to toot his own horn, so without his consent, I'm not going to say why I'm
so sure of it, but please trust me on this: the man *knows* math.

Bill wrote:
wrote:
Let me know what you guys think.

I've been working on a new method (new?) for checking the squareness
of a square using a dial indicator. The method works in theory.
I've tried it and it seems to work in practice. A caveat is that the
square needs a thick edge to support a stylus.

I am going to work on a video demonstrating the process.

http://www.garagewoodworks.com/square_a_square.php

Thoughts?

Sinced/dx (arctan) is close to 1 near 0, yourerror is not very big,

I appreciate the point that you are trying to make, but I don't find the
argument given to be as rigorous as it should be.

I'd enjoy seeing a re-write. I'll help here if you like. I don't think
that L was "well-defined" (consistent) in the present argument
Bill


but your equation which divides an angle by L (before applying arctan)
doesn't make sense. For instance, it suggests that if you choose L
great enough that your error will be as small as you need it to be. I
did not try to redo your derivations, but I am willing to do so if we
don't find a concensus. By the way,you might sketch a triangle
somewhere(tan = opp/adj)for those that may be a bit rusty at doing trig.

Bill

On Thursday, January 3, 2013 7:40:30 PM UTC-5, Bill wrote:
Bill wrote:

wrote:

Let me know what you guys think.



I've been working on a new method (new?) for checking the squareness

of a square using a dial indicator. The method works in theory.

I've tried it and it seems to work in practice. A caveat is that the

square needs a thick edge to support a stylus.



I am going to work on a video demonstrating the process.



http://www.garagewoodworks.com/square_a_square.php



Thoughts?



Sinced/dx (arctan) is close to 1 near 0, yourerror is not very big,



I appreciate the point that you are trying to make, but I don't find the

argument given to be as rigorous as it should be.



I'd enjoy seeing a re-write. I'll help here if you like. I don't think

that L was "well-defined" (consistent) in the present argument

Bill





but your equation which divides an angle by L (before applying arctan)

doesn't make sense. For instance, it suggests that if you choose L

great enough that your error will be as small as you need it to be. I

did not try to redo your derivations, but I am willing to do so if we

don't find a concensus. By the way,you might sketch a triangle

somewhere(tan = opp/adj)for those that may be a bit rusty at doing trig.



Bill

L is the length of the square's edge. It was defined adequately.

I forgot to mention, what you have labeled as "References" are not
references at all.

Please re-do.

Bill

On Thursday, January 3, 2013 8:44:31 PM UTC-5, Bill wrote:
I forgot to mention, what you have labeled as "References" are not

references at all.



Yes they are. I am 'referring' to them in the article. It's done routinely in the literature. See 5d below where as it applies here.

ref·er·ence (rfr-ns, rfrns)
n.

On 1/3/2013 6:40 PM, Bill wrote:
I appreciate the point that you are trying to make, but I don't find the
argument given to be as rigorous as it should be.

From what I've seen, Dr. Grella has a pretty good grasp of mathematics
and scientific principles.

--
eWoodShop: www.eWoodShop.com
Wood Shop: www.e-WoodShop.net
https://plus.google.com/114902129577517371552/posts
KarlCaillouet@ (the obvious)

Swingman wrote:
On 1/3/2013 6:40 PM, Bill wrote:
I appreciate the point that you are trying to make, but I don't find the
argument given to be as rigorous as it should be.

From what I've seen, Dr. Grella has a pretty good grasp of mathematics
and scientific principles.

Yes, there was just probably some confusion aboutnotation.
I just don't think his present work is "camera-ready" yet, for publication.
I think the work needsmorediagrams.

Thanks,
Bill

On Thursday, January 3, 2013 7:24:24 PM UTC-5, Bill wrote:
wrote:

Let me know what you guys think.



I've been working on a new method (new?) for checking the squareness of a square using a dial indicator. The method works in theory. I've tried it and it seems to work in practice. A caveat is that the square needs a thick edge to support a stylus.



I am going to work on a video demonstrating the process.



http://www.garagewoodworks.com/square_a_square.php



Thoughts?



Sinced/dx (arctan) is close to 1 near 0, yourerror is not very big, but

your equation which divides an angle by L (before applying arctan)

doesn't make sense. For instance, it suggests that if you choose L

great enough that your error will be as small as you need it to be.

For the same angle error, as L get longer so does abs(Delta1 - Delta2).

I

did not try to redo your derivations, but I am willing to do so if we

don't find a concensus. By the way,you might sketch a triangle

somewhere(tan = opp/adj)for those that may be a bit rusty at doing trig.



Bill

On 1/3/2013 7:24 PM, Bill wrote:
wrote:
Let me know what you guys think.

I've been working on a new method (new?) for checking the squareness
of a square using a dial indicator. The method works in theory. I've
tried it and it seems to work in practice. A caveat is that the
square needs a thick edge to support a stylus.

I am going to work on a video demonstrating the process.

http://www.garagewoodworks.com/square_a_square.php

Thoughts?

Sinced/dx (arctan) is close to 1 near 0, yourerror is not very big, but
your equation which divides an angle by L (before applying arctan)
doesn't make sense. For instance, it suggests that if you choose L
great enough that your error will be as small as you need it to be. I
did not try to redo your derivations, but I am willing to do so if we
don't find a concensus. By the way,you might sketch a triangle
somewhere(tan = opp/adj)for those that may be a bit rusty at doing trig.

Bill

As I understand his equations the L is not a variable in any given
situation as it is the length of the square. How ever it would be
different depending on whether one used the long or short arm of the square.

I challenge anyone to find a flow in my math.

Good luck.

On Thursday, January 3, 2013 8:30:56 PM UTC-5, wrote:
I challenge anyone to find a flow in my math.



Good luck.

Flaw Not flow. /that was intentional (grin)/

On 1/3/2013 7:32 PM, wrote:
On Thursday, January 3, 2013 8:30:56 PM UTC-5, wrote:
I challenge anyone to find a flow in my math.



Good luck.

Flaw Not flow. /that was intentional (grin)/

Appears to be a matter of resolution. I'm of the camp that if you don't
have perfection as a goal for every step of the process, you will never
scratch that itch some of us are cursed with.

At the same time, I'm just as guilty as anyone of occasionally settling
for less ... mainly due to time, circumstances, the medium
(woodworking), and the need to 'git r' done'.

That said, you are only as accurate as your tools allow ...

--
eWoodShop: www.eWoodShop.com
Wood Shop: www.e-WoodShop.net
https://plus.google.com/114902129577517371552/posts
KarlCaillouet@ (the obvious)