pin comparisons

[Ron Nossaman]

> Dale writes: 
> 
>>>To my mind it doesn't really 
>matter how   .   big the pin is, within reason  a no.1 thru 4 pin as long 
>> as they render easily in the    block. know what I mean.
> 
>    I think so. 

The fitting of the smaller diameter pin in the block is slightly less
critical because of the smaller surface area. A a given PSI change in block
fit will translate to a greater difference in feel at the lever handle with
a large diameter pin than with a smaller diameter. Torque readings (and
feel) will change less with humidity swings with the smaller pins. This is
less noticeable in the low density blocks because there is more resilience
to the material, so the friction gradient isn't as steep as in the high
density blocks that don't compress as easily. At least that is the way I
read it.

I compute ratios of block fit PSI to torque readings at the end of a 10"
lever at:
1/0 1.0
2/0 1.044
3/0 1.074
4/0 1.112
5/0 1.150
6/0 1.189  

No, I don't have a way to measure PSI of the block fit at the pin. I judge
them by feel like everyone else, but this is what the math shows, and it
fits my observations through the years.
 

> Given the amount of pitch change to be had without 
>moving the pin in a usual Baldwin block,  there has to be a lot of give in 
>the system SOMEWHERE!  

There is both flex and torsion (twist). Most of the give in that Baldwin
system is torsion in the very tight pins in the relentlessly unresilient
block. Put those pins back in the vise and measure how far the end of the
lever handle moves from pin twist between no load, and that ten pounds
applied tangent to pin rotation. Then apply (by feel, and considerably more
than ten pounds) the pull you would expect it to take to turn a Baldwin pin
(up or down average) and measure that. A small diameter pin in a tight
block will twist a long way at the top before the torque in the pin
overcomes the static friction at the bottom of the pin. A large diameter
pin doesn't twist as easily, so the bottom will move sooner. When the
static friction between the pin and block is significantly higher than the
sliding friction, both pins will snap in the block as they move, but the
smaller diameter seems to snap less.   

My call.

Ron N