ALL SQUARES ARE NOT SQUARE
definitions of a square are: 1) A rectangle with all four sides
equal and 2) An instrument having at least one right angle and two
straight edges used especially to lay out or test right angles.
What prompted or inspired this impromptu short story was the recent construction of
a toy box
and/or blanket chest for our youngest Grandson Xander McKnight Gonzales,
whereas I was having some difficulty getting things squared up. On
smaller construction projects less than 8 to 12 inches in length, a little
bit off is not near as noticeable as something that is over forty (40) inches
in length x 21 x 21 or more. Using regular marking and layout tools, you can
only get so close depending on your ability to transfer and/or mark a line
or reference point which is subject to human error. The human eye
can only distinguish and discern but so much accuracy and that is when precision
measuring tools and instruments come into play such as micrometers,
machinists squares, etc.
Prior to building the toy box, I made special
for doing right
angle and forty-five degree miter cuts using several different wooden sleds
that reference off the miter slots on my table saw.
Example below of my custom made miter sled for forty-five degree picture frame type
I used this fixture for trimming a forty-five degree angle on the ends of
my turkey box call lids but it is just as simple to use a fixture or free
hand sand on a 6 x
48 inch vertical belt sander to do the same thing and maybe quicker without
fear of chip out. I
later used the fixture for cutting custom made walnut moldings for the
boxes I made last year. You could use a miter chop saw but
that would be a lot of rotating the saw from left to right cutting miters and the sled
is the way to go.
While building the custom keepsake boxes, I had trouble getting the
forty-five degree miter joints to a perfect ninety degree (right angle) fit
and had to abandon the usage of a
framing square and a couple other smaller
squares and keep adjusting the angle on the fixture until I could get a near
perfect ninety (90) degree fit which was difficult. I later purchased
a used Starrett Model No. 20 6
inch machinists square as my standard and totally pleased with it.
Just recently, I found that my framing square and three or four other smaller
squares and right angle indicator tools were not perfect enough, but only in the
ball park. If you place two squares on a flat surface back to back and
you can see daylight between the two longer side blades, one of the two is
not square. It doesn't take but a few thousands of an inch to throw
four miter joints out of square. When you are using those type tools in
combination with something like a hand held skill saw, that is probably as
accurate as you need to be; no disrespect to the vast number of craftsmen
that use those tools quite efficiently. But for something more precise
where your angles have
to be near perfect as can be, it is a challenge using tools that are not
accurate enough to begin with. Then again, it all depends on what a person will
settle for his or her own personal standard!
Anything worth doing, is worth doing right.
Below is a pix of some of the right angle tools that I have accumulated
since the late 1960s:
All of the above right angles/squares are not square except the lower right Swanson
7 inch Speed Square tool but the forty-five (45) degree angle side is off. The framing square is
at least 1/32 inch off on the long side even after I adjusted it by penning
a few dimple holes with a punch to displace some metal but it was too far
out to correct. The yellow handle multi-purpose tool was way off also.
The next pix shows two Starrett model No. 20 machinists squares that I
now use for all my reference work and set-up, etc. You don't see any
daylight between those two blades back to back and each one will register
square on all sides.
I purchased the used 6 and 12 inch square off EBay and if you purchase the
6 inch Starrett Machinists Square No. 20 new, it will set you back well over 400 bucks
in a 6 inch length one and that is an
expensive tool in my book. Without a precision square as perfect as
you can get, you will never have a near perfect cut. You are only as
accurate as your precision layout tools and your ability to
properly transfer a reference line from them and that is a FACT! As I have said so many
times on this website, "Most of the time, you get
what you pay for."
Below is pix of the fate of four of the right angle squares in the above pix:
I recently purchased a used Starrett Machinists Square Model No. 20 off
is 18 inches in length and got an exceptional deal on it. I watched
the bids sit for a few days and placed my maximum bid a half minute before
the sale ended and outbid the pack of 22 bids. I might need a wheel barrow to haul it around since it is
heavy......grin if you must!
The above square will be used as my master to calibrate all my jigs,
fixtures as needed! Sometime in the future, I will make a plywood case
with piano type hinge to store it properly.
Starrett manufacturers precision tools and when I had my
musical instrument shop
in the late 1960s, purchased a good amount of their measuring tools which
was a necessity. A local manufacture, Coffin Hoist let me use a few of
their larger 11 to 14 one inch dial micrometers for the measurement of
pre-war Gibson banjo components, whereas I later purchased a
large Starrett 24 inch vernier caliper for the bulk of my instrument
measurements as well as smaller micrometers, etc.
My next project will be the recalibration of my miter and ninety degree
table saw sleds to get them as perfect as I can and hopefully my next
woodworking project will be a little easier and more precise.
Web published by Bill aka Mickey Porter on 04-02-16 and updated on
PRECISION TRIANGLES AVAILABLE
If you are looking for a precision made triangle, tee square; check out
the products offered by
Pat Warner. Below is a pix of his
precision made triangles from his website:
Web published update by Bill aka Mickey Porter on 09-25-16.