Since the pole
measured door leg lengths from the floor to the bottom edge
of the head jamb, he has added a 1/4" reveal and one casing
width to the distance from the stop to the center of the quick
rule attached to the saw fence.
In other words,
he has converted from the short point length that he measured
(from the floor to the bottom of the door jamb) to the long
point length he needs in order to measure his already mitered
legs from the Quick Rule stuck on the Saw Fence. And he added
in the 1/4" reveal to the stop length as well.
The stop in
this situation is not used for cutting; it is used for measuring.
He simply shoves the already mitered end of the casing to the
stop, marks the bottom of the leg to length from the rule stuck
on the saw fence, slides the casing a few inches under the saw
blade and whacks the bottom square to his mark.
You will notice
in the picture above that the Quick Rule shown on the story
pole is the one on the end that we used in an earlier picture
to measure the left leg of door 1X. This end of the story pole
will be touching the floor when we measure the right leg of
door 1X. The rule on that end is the one we aligned to the rule
on the fence.
I use the actual
casing for the story pole for two reasons. It has the identical
footprint on the floor, and when I am reading my measurements
I can see whether they are for left or right legs by the story
pole profile itself. If I am cutting right legs I look at the
pole as if it is a right leg, and read them off. The left leg
measurements will be upside down on the bottom end of the pole.
Anything I can do to prevent me from confusing myself, or losing
something, is worth it to me.
It is Absolutely
Critical that the Quick Rules (or whatever you
are using) on each end of the story pole are set at Exactly
same distance from their respective
ends. It is also Absolutely Critical
that the stop is Perfectly Square
to the fence on the saw. This is because we are using the same
stop to measure both left and right legs. The right leg miter
will contact the stop near the extension wing fence; the left
leg outboard from the extension wing fence. If the stop is 1/8
out of square in the width of the casing, one of the legs will
be either an eighth short or an eighth long.
And it is Absolutely
Critical that the stop does not move; in fact,
I often run a couple screws through it for good measure in addition
to welding clamps.
None of the
above is hard to do at all, and takes much less time to do than
to explain. You old cabinet makers out there will recognize
this as nothing more than a variable, re-usable "tic stick"
without the "tic" but with the rule.