PSN-L Email List Message
Subject: Re: Glass?
From: tchannel1@............
Date: Mon, 12 Nov 2007 11:35:41 -0700
Chris, You have enlighten me. "Not to put too fine a point on it" =
(the subject that is) but would then, diamond on diamond be the best of =
all?
Not knowing how I might do this, but I have many carbide tipped saw =
blades. I have never looked too closely at one tooth, but they have a =
point and some flat surfaces. If I could get some of these teeth off, =
or get replacement teeth from the people who resharpen my blades, would =
these be good pivots surfaces? Say one tooth point resting on one tooth =
flat side. (arranged in a set of two) pivots for a vertical pendulum? =
Thanks, Ted
----- Original Message -----=20
From: ChrisAtUpw@..........
To: psn-l@.................
Sent: Monday, November 12, 2007 10:07 AM
Subject: Re: Glass?
In a message dated 12/11/2007, tchannel1@............ writes:
Hi Folks, Just wondering about materials for roller on roller or =
balls on plates. I know the limitations of glass, but a question about =
its smoothness, is the surface of glass as smooth or smoother than these =
hardened and polished steels?
Hi Ted,
Probably about the same. You get an optical finish with fine =
polish on metal. However glass is a rapidly solidified liquid.
My second question is one of friction: If you have one ball on one =
plate you would have one point of friction. If you have one ball =
resting between two rollers, (in the V) you would have two points of =
friction, but the load would be divided, because its resting on two =
points, so is the end result of friction loss the same?
It is the surface to surface properties which are important. The =
actual static friction is proportional to the load, so halving it and =
using two points will likely give a very similar result. However, if you =
put a fixed vertical load on a ball resting on two rods, the loads at =
the two points are increased to give the same resolved vertical force. =20
When we talk about friction in pendulum suspensions, it is not =
this static friction to which we are referring. It is the tiny rolling =
contact loss as the materials are compressed and relaxed. No materials =
are perfectly elastic. Glass is poor in this respect and tends to chip =
easily.
Regards,
Chris, You have enlighten me. "Not to =
put too=20
fine a point on it" (the subject that is) but would =
then,=20
diamond on diamond be the best of all?
Not knowing how I might do this, but I have many carbide tipped saw =
blades. I have never looked too closely at one tooth, but they =
have a=20
point and some flat surfaces. If I could get some of these teeth =
off, or=20
get replacement teeth from the people who resharpen my blades, would =
these be=20
good pivots surfaces? Say one tooth point resting on one tooth =
flat=20
side. (arranged in a set of two) pivots for a vertical=20
pendulum? Thanks, Ted
----- Original Message -----
Sent: Monday, November 12, 2007 =
10:07=20
AM
Subject: Re: Glass?
Hi Folks, Just =
wondering about=20
materials for roller on roller or balls on plates. I =
know the=20
limitations of glass, but a question about its smoothness, is the =
surface of=20
glass as smooth or smoother than these hardened and polished=20
steels?
Hi Ted,
Probably about the same. You get an =
optical=20
finish with fine polish on metal. However glass is a rapidly =
solidified=20
liquid.
My second question is one of =
friction: If you=20
have one ball on one plate you would have one point of =
friction. If=20
you have one ball resting between two rollers, (in the V) =
you=20
would have two points of friction, but the load would be divided, =
because=20
its resting on two points, so is the end result of friction =
loss the=20
same?
It is the surface to surface properties =
which are=20
important. The actual static friction is proportional to the =
load, so=20
halving it and using two points will likely give a very similar =
result.=20
However, if you put a fixed vertical load on a ball resting on two =
rods,=20
the loads at the two points are increased to give the same =
resolved=20
vertical force.
When we talk about friction in pendulum=20
suspensions, it is not this static friction to which we are referring. =
It is=20
the tiny rolling contact loss as the materials are compressed and =
relaxed. No=20
materials are perfectly elastic. Glass is poor in this respect and =
tends to=20
chip easily.
Regards,
=
Chris
[ Top ]
[ Back ]
[ Home Page ]