centered on a tool

[Robert Edwardsen]

I also have a collection of small drill bits I keep with my center pins that
I use to enlarge the birdseye so I don't split it when trying to match the
enlarge bushing on delicate flanges that I don't want to rebush.

Rob Edwardsen

----- Original Message -----
From: "Fred Sturm" <fssturm@unm.edu>
To: <caut@ptg.org>
Sent: Thursday, August 23, 2001 10:48 AM
Subject: Re: centered on a tool


Hi, Joe,
Yes, there's a jump in "imperial" sizes (inches) somewhere between #23
and #24. The jumps become quite large between sizes, as you note, maybe
a sort of geometric progression. I keep a few of the larger sizes on
hand for emergency use - mostly the odd ancient upright with a couple
hammers flopping around. Occasionally the large pin is less work than a
rebush (depending on birdseye condition). For high quality work, 22.5 is
about the largest size that works, from the point of view of firmness
versus friction. I prefer to hold to #22. Larger sizes have too much
surface area. And leave too little felt in the hole. Kind of like 5/0
and larger tuning pins - useful in some circumstances, but not
recommended where it matters.
Regards,
Fred Sturm
University of New Mexico

Joe & Penny Goss wrote:
>
> Hi all,
> In measuring center pins I have discovered that my pins do not always
> increase in increments of .001
> They go #18 is .046#18.5 is .047 #19 is .048 19.5 is 49
> #20 is 50 # 20.5 is 51 # 21 is 52 #21.5 is 53 # 22 is
> 54.
> I do not have any 22.5 pins but presume that they are .055 becuase
> #23's are .056 and no #23.5 pins and wonder the size for the #24 pins
> are.059 No #24.5 and then #25 is .063 and no #25.5 and the last pin
> size 26 is .066
> The break in size progression seems to be between size #23.5 and size
> #24
> Question 1. are my missing center pin sizes available? #22.5, 23.5
> and 24.5?
> 2. are these larger sizes used by many? {#22 and
> larger}
> 3.At what size do you deide to rebush rather than
> repin?
> 4. If larger accurate reamers were available would
> you think of using a larger pin size?
> Joe Goss
> imatunr@srvinet.com
> www.mothergoosetools.com