Bernard,

Think about it... The table top (miter slots) are not parallel to the
blade - hence the distance from a point on the front of the blade and a
reference point on the miter gauge head will be more/less as the miter gauge
is moved to the rear of the blade. Do you need a drawing to visualize it ?
ASCII art below is exaggerated but shows what I mean. As the Ref point
moves towards the rear of the blade the distance from Ref point to the blade
is less. Now if the miter gauge head is not perpendicular to the slot, that
introduces even more error as well and if the slot is not perpendicular to
the table edge - more error is introduced.



| | \ \
| | \ \
| | \ \
| | \ \
|------------| \ \
Ref \ \

Miter Slot - Head Blade


Bob S.


"Bernard Randall" wrote in message
...
Irrespective of the angle of the miter head the distance of anything fixed
to it should be the same when the head is moved between the front and rear
of the blade. As was originally stated a marked tooth is being used as
the
reference, there bye eliminating any eccentricity of the mounting boss.
When the blade is truly parallel to the miter slot it may not be at 90
deg.
to the front of the table but the fence has adjustment to compensate for
this.

Though a dial indicator is the recommended tool feeler gauges work just as
well.

Bernard R

"Bob S." wrote in message
.. .
Larry,

If he used a used a try square to align the miter head to the blade, the
head would be at one position (angle to the blade) and when it's holding
a
pencil, it's used at the front of the blade and then at the rear. The
difference will be more/less as the gauge is moved along the blade.
With
the miter aligned to the blade while it's out of adjustment and then
using
it to try and align the slot to the blade is not going to work.

He could turn the miter gauge upside down in the slot and align the head
with the front edge of the table. Then reverse it and put it in the
slot
upside down again at the rear edge and see if there's a difference. If
so,
then the slot is not perpendicular to the edges referenced.

So saying it doesn't make a difference is not exactly correct - right?

Bob S.


"Lawrence R Horgan" wrote in message
...
Seems to me it wouldn't matter how the miter gauge was aligned. Even
if
you
had the guage at, say 29 degrees, the difference between the pencil
point
and the blade at the front or back of the blade would be the same.