Changing roller size.

[Richard Moody]

>
> For an imformative exercise, get a drawing of an action, a set of
> compasses, and scribe every radii.
> No conclusions just observations.
>  Little things like the rake angle at the top of the jack becomes
> significant, this will determine friction, due to the contact area. But
you
> change the angle of the jack WRT the knuckle core, it has a similar effect
> as changing the rake of the jack tip.
>
> Just some ramblings to drive other's as nut's as I.  <G>
>
> Roger Jolly

Yeah, but you gotta remember that action parts wear.  The capstain cushion
gets packed in, the roller gets comparessed, and the hammer sooner or later
will need to be filed.    Any or all three will necessitate raising the
hammer line.  We all know that the jack makes an impresion on the let off
felt and what happens when this gets a quarter turn as compared to half a
turn or a whole turn even.   I don't think the consequences of 1 mm are as
grave as they can be imagined.  The pencil line in the drawings when two
meet I bet gets a good part of 1 mm.
     I think those who designed the action took wear into account.   So the
true picture of the ideal lines on the draft board or in a brand new action
might should look a little bent.  If indeed the action designer desires a
straight line to begin with.  When you set straight lines to radii there are
99 out 100 points the line will not be straight when the action is in
motion.
     I thought we were talking about the difference between an 11 mm roller
and a 10 mm roller.  I would not be surprised if they compact more than 1mm.
Besides I bet in a set of new rollers you can find variances as much as 1
mm. I doubt if you can expect better than that from a cylinder built from
compressed felt cloth and leather.  Heck can they even get leather to better
than .5 mm consistency?
---ric  (the c stands for closenuf)