Meredith,
Here is an alternative. http:/=
/www.vxb.com/page/bearings/CTGY/Loose-Ceramic-Balls
VXB sell ball bearings for bicycles. You can purchase 10 each ceramic =
balls made
from Si3N4 for only 19.95 and shipping only 3.98. Try them, they are =
very hard.
It seems VXB is very big in the bike racing field. Check them out. =
I’m
now in process of tuning my Lehman and have the resonant frequency up to =
25
sec.
Gary
From:=
psn-l-request@.............. [mailto:psn-l-request@............... On =
Behalf
Of meredith lamb
Sent: Saturday, June 07, 2008 10:04 AM
To: psn-l@..............
Subject: Pivot balls; carbide and corundum =
reminder
Hi all,
Small Parts Inc. stocks carbide, synthetic ruby (red) and sapphire =
(clear)
balls that could probably
replace (and very likely enhance the pivot) of your steel ball bearings =
in your
seismometer pivots.
The corundum sizes range from 1/64" up to 1/8" @ $3.45 up to =
$4.00
each. You can buy in
quanity somewhat cheaper. The sphericity (roundness) listed is
0.000025".
http://www.smallparts.com/products/descriptions/brb.cfm=
http://www.smallparts.com/products/descriptions/BSP.cfm=
The tungsten carbide balls range from 1/16" up to 1/2" @ $3.25 =
up to
$16.80 each. They
have metric sizes also. The sphericity listed is =
0.0006"...quite
abit less round than the corundum.
http://www.smallparts.com/products/descriptions/btc.CFM=
The "big bite" of it all is their shipping/handling costs ~ =
$14.00
(USA) irregardless of the small weight.
Their FedEx "2 day" shipping could be up to 4-5 days. =
Ground
shipping ~ 7 to 10 or more days.
Take care, Meredith