David Hendley on fri 2 mar 01
Craig, if your wheel head is wobbling you probably need
new bearings for the wheelhead shaft.
If you need new bearings, you will notice side-to-side
"play" in the wheelhead.
Another possibility is that the wheelhead is bent. If that
is the case, everything will feel tight, but the wheelhead
will dip down at the same spot on every revolution.
If your Pacifica is like mine, you have to remove the entire
piece of plastic from the top of the table to get to the top
bearing. It's glued on, and you just (gently) pull it off.
You can buy new bearings at the bearing supply house.
If the wheelhead is bent, the best bet is to just buy a new
one from Pacifica (Laguna).
----- Original Message -----
From: craig clark
Sent: Thursday, March 01, 2001 11:58 AM
Subject: Re: Homemade wheel accessories
| I've been keeping up with the discussion about building an electric wheel
| because I'm considering designing and building one that will easily handle
| 75 to 100 lbs of clay. I've got a Pacifica 800 and it does the job well
| enough, but is showing wear and tear (I've developed a wobble in the wheel
| head that is probably due the torque force applied when throwing larger
| diameter platters- 30 inches plus.) Any suggestions?
| Also, what are throwing stones????????????
| Craig Dunn Clark
| Houston, Texas
Michael McDowell on sun 4 mar 01
David Hendley's advice on replacing the bearing is right on, IF, as he says,
you need new bearings (in which case you'll notice side to side play). I don't
know that a bent wheelhead is really a "get a new one from the factory"
problem though. A few years back, the Pacifica factory was just a little ways
from here. I remember stopping by one time when Bob Lutweiler, the developer
of the wheel, was straightening wheelheads for a new bunch of wheels. As he
related the story, the machining by the people who make the heads was rarely
as perfect as a potter likes. That final amount of wobble was taken out at the
factory with a mallet. Bob would patiently attach each new wheelhead to its
wheel, then hold a magic marker just above the spinning head to mark only the
highest point. Then he'd whack that high part with a mallet, and check again.
Personally, if my wheelhead ever develops a bend maybe as a result of using it
for a stool or a ladder or something, I think I'll try the mallet myself.
Whatcom County, WA USA
Claude Stephens on mon 5 mar 01
Your right about the Pacifica Mallet method. I was experiencing
difficulties with a wheelhead a couple years ago. My call for help to
Pacifica yielded the same results. It seemed a bit loony to me for something
I thought required tight tolerances to be adjusted with a good whack. But I
knew they were the folks in the know and luckily I had the use a fixed
Micrometer to take the place of the magic marker. I did mark the head with
the marker as the high spot crested no different from you. The Micrometer
just afforded me the actual numbers to prove the method.
Sure enough just as advertised the mallet method was a success. It's
been a while and I'm not sure of the numbers but it seems like the correction
was from .012" to .004".
Enough fun, time for work and working for the weekend's clay.
Claude - A lurker that waits for the proper time to speak and in constant
appreciation of those that have spent their life doing what I've only found
and are kind enough to share what they can.