Festool MFS Fence System Instruction Manual page 12

so one tenth of a millimeter is just .004"
(four thousands of an inch) which most of
us would have a hard time seeing even
with the most accurate measuring stick.
If the cut lengths of your extruded pieces
are off by just one tenth of a millimeter,
the resulting diagonal measurement will
change by more than one tenth of a mil-
limeter. So, don't get hung up on what
your measured diagonal is, only that the
two are the same so you know you have
as close to a perfect square as you can
measure.
Or, as I do, if you have a good reference
square that you trust, use it to confirm
that your MFS rectangle
is really square. If you
measure any difference
at all across the diago-
nals, loosen the
screws, make sure your
ends and edges are
carefully aligned and
tighten them again.
The resulting rectangle
is very rigid and popu-
lated with all those nice
"T" and "V" grooves so
there is no limit to how
you can use it to square
up just about anything
you make. The ruler
markings along all four
edges make for good
reference settings.
If you need an even bigger square, sim-
ply use longer extrusions or put two or
more extrusions end to end to form
longer ones.
If you need an open "L" or "T" shaped
square rather than a rectangle, you can
place the end connector inserts on both
12
Two MFS profiles can be joined
anywhere along the edges to
form a "T" or "L" square
sides of one extrusion so you draw it very
tightly up against the edge of another to
form a large "L" or "T" with very close to a
perfect 90 degree corner.
I can't measure any out of square on my
extrusions joined this way when meas-
ured with the class 2 steel reference
square shown which has 500mm by
250mm arms. Since the degree of
square with just two pieces joined to-
gether is dependent on just how square
the ends of the extrusions were cut, I
would hesitate to call it "perfect", but it is
very close.
When you put all four sides together, any
error in how square the
ends were cut will tend
to be cancelled out re-
sulting in a rectangle of
quite significant accu-
racy, certainly more ac-
curate than that
stamped framing
square you might have
been using up to this
point and, as we will
see in the next section,
far more useful than a
similar sized reference
square.
Now that you have a
really good large
square, start by laying
out a known square
corner into which you
can clamp all your square and rectangu-
lar components like rail and stile doors,
panels and the like. If you own a Festool
Multi-function Table you can quickly make
squaring arms as shown in the manual
"Getting the Most from the Festool Multi-
function Table" available for free down-
load from the Festool USA web site.