RE: Ball bearings
Subject: RE: Ball bearings
From: Terry Fritz <twftesla-at-uswest-dot-net>
Date: Wed, 16 Jun 1999 20:27:55 -0600
I ended up grinding a flat in 1/4 inch ball bearings (electric hand
grinder) and soldering them to 1/8 inch brass rod. The torch made the
bearings turn brown but I don't care at this point :-) Pictures of the gap
on the new filter board are at:
The bearings have zero pre-arc problems and totally solved the problem I
was having with sporadic firing!!! I don't think the solder will melt
since the safety gaps don't run long before I hit the off switch. I have
MOVs in this design too which would eat the high voltage if a ball did fall
off. However, the balls do seem solid as rocks on the rod. I positioned
them in a vice and heated them with a torch to solder them with high temp
Pre threaded balls, as many have suggested, would have been better but
this is how I ended up...
The ball bearing material is far harder than any cobalt drill bit and I
smashed a nice punch trying to make a dent in them for a drill bit.
Apparently, heating the bearings to red hot will de-temper them to where
they can be drilled. Any drilling or filing was useless against this very
hard material. However, a hand grinder ground flats in them like butter...
For my 15kV neon, I set the gap at 0.188 inches but I live at 5300 feet so
that won't apply to most who live near sea level...
I got the bearings from cheap "Lazy Susan" turn table bearing from the
hardware store. A little prying with a screw driver allows all the ball
bearings to fall out.
This was obviously more complicated than had I originally intentioned. But
I think I "won" in the end :-)
Many many thanks for all the suggestions that help me through this ordeal!