Hi Meredith,
best picture i can take is at http://www.daleh.id.au/pictures1.html
that is about 12X
Under 10X glass no sign of grinding marks, the reflection in the image =
is my window near where i took the picture.
3 Rods ? as in >|o|< arrangement ?
ta
Dale
----- Original Message -----=20
From: meredith lamb=20
To: psn-l@.................
Sent: Wednesday, June 18, 2008 1:41 AM
Subject: Re: Tungsten Pins
Hi Dale,
Good; at least you tried such. I do wish you had a real closeup =
camera and/or a web site to show the rounded end. My guess is that it =
is diamond
wheel ground off and isn't anywhere near as round as a true sperical =
ball. Under ~ >15x magnifcation you visually might see "jerky steps" =
going
up to the domed rods end point top. All those little steps likely =
significantly impede smooth rotation where they make contact; as =
compared to a
much more finely rounded ball.
This reminds years back of obtaining a unheat treated tool steel drill =
rod shank/blank. Boy, was that rod so visually shiny! Under =
magnification,
the surface was so badly spirally groove marked from the lathe tool, =
it was completely unuseable in a cross rod pivot test, and yielded the
shortest time for free oscillation time duration of any material I =
had.
I "presume" your domed rod end is making contact on a flat surface.
If you're game; just for fun, you might also sometime try a true =
crossed (3 rods) rod pivot on your (presumed) experimental "test" =
Lehman....it can
work almost frictionless very well....but they do have a obvious =
tendency to "slip" or "walk" horizontally and vertically (or, at any =
angle); so you will
probably have to have alotof setup patience with adjustments. All of =
which is why......the 2 rods and a ball is used; it totally eliminates =
all the=20
otherwise pesky vertical slip/walk problem on a Lehman, but gets quite =
decent results.
Take care, Meredith=20
=20
On Mon, Jun 16, 2008 at 8:57 PM, Dale Hardy =
wrote:
Hi Meredith,
omitted to mention those 'capstan' rods also have a 'domed' end =
which has been used successfully as a pivot point on the arm of a lehman
Dale
-------------------------------------------------------------------------=
-----
Internal Virus Database is out-of-date.
Checked by AVG.=20
Version: 7.5.524 / Virus Database: 269.24.6 - Release Date: 3/06/2008 =
12:00 AM
Hi Meredith,
best picture i can take is at http://www.daleh.id.au/pic=
tures1.html
that is about 12X
Under 10X glass no sign of grinding =
marks, the=20
reflection in the image is my window near where i took the =
picture.
3 Rods ? as in >|o|< arrangement=20
?
ta
Dale
----- Original Message -----
From:=20
meredith lamb
Sent: Wednesday, June 18, 2008 =
1:41=20
AM
Subject: Re: Tungsten =
Pins
Hi Dale,
Good; at least you tried such. I do wish you had a real =
closeup=20
camera and/or a web site to show the rounded end. My guess =
is that=20
it is diamond
wheel ground off and isn't anywhere near as round as a true =
sperical=20
ball. Under ~ >15x magnifcation you visually might see =
"jerky=20
steps" going
up to the domed rods end point top. All those little steps =
likely=20
significantly impede smooth rotation where they make contact; as =
compared to=20
a
much more finely rounded ball.
This reminds years back of obtaining a unheat treated tool =
steel=20
drill rod shank/blank. Boy, was that rod so visually =
shiny! Under=20
magnification,
the surface was so badly spirally groove marked from the =
lathe tool,=20
it was completely unuseable in a cross rod pivot test, and =
yielded=20
the
shortest time for free oscillation time duration of any material =
I=20
had.
I "presume" your domed rod end is making contact on a flat=20
surface.
If you're game; just for fun, you might also sometime try a =
true=20
crossed (3 rods) rod pivot on your (presumed) experimental "test"=20
Lehman....it can
work almost frictionless very =
well....but they=20
do have a obvious tendency to "slip" or "walk" horizontally and =
vertically=20
(or, at any angle); so you will
probably have to have alotof setup =
patience=20
with adjustments. All of which is why......the 2 rods and a ball =
is=20
used; it totally eliminates all the
otherwise pesky vertical=20
slip/walk problem on a Lehman, but gets quite decent results.
Take care, Meredith
On Mon, Jun 16, 2008 at 8:57 PM, Dale Hardy =
<photon1@...........>=20
wrote:
Hi Meredith,
omitted to mention those 'capstan' =
rods also=20
have a 'domed' end which has been used successfully as a pivot point =
on the=20
arm of a lehman
Dale
Internal Virus Database is out-of-date.
Checked by AVG. =
Version:=20
7.5.524 / Virus Database: 269.24.6 - Release Date: 3/06/2008 12:00=20
AM