Hi all,

I ran acouple more table top/edge tests with a stainless steel cross rod
(1/4" diameter),
on acouple of variations of glass rod I found in the house/garage. I presum=
e
both glass
items were common glass and not any special heat/stress/strength types. The
glass
was used as the two supports rods for a stainless steel cross rod/boom/mass
with a
weight of ~1.75 pounds and a natural oscillation period of 1.25 seconds.
This test was
run in a vertical hanging mass setup like a "S-G". There was no oil
lubrication. The
tests are only a crude measure of the friction involved with the two glass
surfaces and
the stainless steel cross rod.

The first glass model was two 1/8" diameter solid glass rods, which appears
to be
common extrusion, and the surface was quite smooth to the touch and it had =
a
mirror
like light reflective surface. With a 1/4" deflection of the mass and no
dampening, the
mass oscilliated for ~ 6 hours and 20 minutes. This time was ~ 40-50 minute=
s
longer
than any steel on steel hinges I've tried thus far.

The second glass model was two .196"-.199" diameter glass tubes with a wall
thickness
of 0.025". Again, it was a extrusion glass and the surface appeared the sam=
e
as the
above test model. With a 1/4" deflection of the mass and no dampening, the
mass
oscillated for ~4 hours and 15 minutes. This was unexpected. A trial re-run=
,
even after
rotating the glass, yielded approximately the same oscillation time. Why it
oscillated
less time than the solid glass rod is unknown at this time.

I'd think that using such would be limited mostly to a vertical hanging mas=
s
setup,
with a light weight boom/mass arrangement. One would have to likely increas=
e
the
glass rod diameter for other hinge arrangements....and likely limit the
boom/mass
weight, and even then, it might affect/ruin the glass cross rod.

Upon examination of the glass rods after their tests, there was not noted
any glass
surface crushing, or wear marks where the stainless steel cross rod had
been; even
with using a 16 power jewelers loupe. Long term use wear is unknown, but
glass
rod damage is of course possible. Older previous tests with various
diameters of
ball bearings on glass also didn't show any marks.

Round glass rods/tube can come in a variety of objects, like drink stirring
rods,
lab stirring rods, decorative glass rod objects hanging from misc., and of
course
bulk varieties of rods/tubes from sellers, in a variety of diameters.
Usually none
of the glass rods are exact consistent diameters, and they can vary abit in
such
from one rod to the next; or even in diameter measurements along the same
rod.

I even tried acouple indoor wall hanging thermometer rods. They have a
flattened
diameter, and their cross section shape is almost triangular. That test ran
for
5 hours. Thermometers are glass tubes, with closed ends.

*Common glasses for drinking, could be a interesting test subject, if, the
edges
are rounded and smooth enough. If the glass jar is big enough, one might be
able to put a hinge atop, and the rest of the mechanisms inside I suppose.
Everything is "fair game" for trials.

I see no real mounting problems with varying glass diameter rods; nor, is
the
cross rod zeroing application approach much different.

Using only glass for the two supports of a crossed rod hinge/suspension
appears
to be a "mixed bag", as it can be better, or worse, than results I've seen
with steel
on steel hinges in the sense of friction.

From the results above, it "could" imply that using all extruded solid glas=
s
rods
for the cross rod and two supports, and not glass tubes, may yield a more
friction
free crossed rod hinge/suspension.

Take care, Meredith Lamb
Hi all,



I ran acouple more table top/edge tests with a stainless steel cross rod (1=
/4" diameter),

on acouple of variations of glass rod I found in the house/garage.  I =
presume both glass

items were common glass and not any special heat/stress/strength types.&nbs=
p; The glass

was used as the two supports rods for a stainless steel cross rod/boom/mass=
 with a

weight of ~1.75 pounds and a natural oscillation period of 1.25 seconds.&nb=
sp; This test was

run in a vertical hanging mass setup like a "S-G".  There wa=
s no oil lubrication.  The

tests are only a crude measure of the friction involved with the two glass =
surfaces and

the stainless steel cross rod.



The first glass model was two 1/8" diameter solid glass rods, which ap=
pears to be

common extrusion, and the surface was quite smooth to the touch and it had =
a mirror

like light reflective surface.  With a 1/4" deflection of the mas=
s and no dampening, the

mass oscilliated for ~ 6 hours and 20 minutes.  This time was ~ 40-50 =
minutes longer

than any steel on steel hinges I've tried thus far.



The second glass model was two .196"-.199" diameter glass tubes w=
ith a wall thickness

of 0.025".  Again, it was a extrusion glass and the surface appea=
red the same as the

above test model.  With a 1/4" deflection of the mass and no damp=
ening, the mass

oscillated for ~4 hours and 15 minutes.  This was unexpected.  A =
trial re-run, even after

rotating the glass, yielded approximately the same oscillation time.  =
Why it oscillated

less time than the solid glass rod is unknown at this time.



I'd think that using such would be limited mostly to a vertical hanging mas=
s setup,

with a light weight boom/mass arrangement.  One would have to likely i=
ncrease the

glass rod diameter for other hinge arrangements....and likely limit the boo=
m/mass

weight, and even then, it might affect/ruin the glass cross rod.



Upon examination of the glass rods after their tests, there was not noted a=
ny glass

surface crushing, or wear marks where the stainless steel cross rod had bee=
n; even

with using a 16 power jewelers loupe.  Long term use wear is unknown, =
but glass

rod damage is of course possible.  Older previous tests with various d=
iameters of

ball bearings on glass also didn't show any marks.



Round glass rods/tube can come in a variety of objects, like drink stirring=
 rods,

lab stirring rods, decorative glass rod objects hanging from misc., and of =
course

bulk varieties of rods/tubes from sellers, in a variety of diameters. =
 Usually none

of the glass rods are exact consistent diameters, and they can vary abit in=
 such

from one rod to the next; or even in diameter measurements along the same r=
od.



I even tried acouple indoor wall hanging thermometer rods.  They have =
a flattened

diameter, and their cross section shape is almost triangular.   T=
hat test ran for

5 hours.  Thermometers are glass tubes, with closed ends.



*Common glasses for drinking, could be a interesting test subject, if, the =
edges

are rounded and smooth enough.  If the glass jar is big enough, one mi=
ght be

able to put a hinge atop, and the rest of the mechanisms inside I suppose.<=
br>
Everything is "fair game" for trials.



I see no real mounting problems with varying glass diameter rods; nor, is t=
he

cross rod zeroing application approach much different.



Using only glass for the two supports of a crossed rod hinge/suspension app=
ears

to be a "mixed bag", as it can be better, or worse, than results =
I've seen with steel

on steel hinges in the sense of friction.



From the results above, it "could" imply that using all extruded =
solid glass rods

for the cross rod and two supports, and not glass tubes, may yield a more f=
riction

free crossed rod hinge/suspension.



Take care, Meredith Lamb