blow discrepancy:technique?

[David Renaud]

I have always measured a straight line from hammer tip to string.

But:
A colleague insists the best way to determine travel in an upright
is to push a hammer molding forward to the stings
with a ruler, mesuring from the back edges of the respective
hammer moldings.

I find that this method always produces a slightly reduced
reading. On my action model a 1/16th reduced reading.
This is apparently due to the hammer always traveling
from an angled position to a perpendicular position relative to
to strings. It will always reach slightly forward as it assumes a
perpendicular position and block premature of its straight
line measurement. So he could be right.

But:
The hammer is traveling though an arc. So it is greater
then any straight line measure anyway. So I still I'm still right.

Never thought much on this before. Was always concerned
more with relationships working between travel distance
and key travel for correct aftertouch then travel being 1 7/8.
The test seems to support this as it gives +/- 1/8 to make it
work. Never less in a test siduation 1/16+ difference due
to measuring technique is too much.

So is my hammer to string, straight line technique
from the front of the hammer wrong?
Or is is better to approach these measurements from the
rear measuring molding to molding with the hammer engaged?

                                                     Cheers
                                                     Dave Renaud