Ric Swenson on wed 4 aug 99
Hey Guys and Gals,
Here in Vermont we use a three legged milking stool. Always have and
IMHO.....Three posts for kiln furniture :
1.) work better
2.) last longer.
3.) warp less.
4.) are just as strong as 4 post systems.
5.) you need to own fewer posts, total.
6.) look better.
7.) accomodate more and bigger ware
8.) theoretically and practically are THE solution to the issue.
I agree with you nikom.
nikom chimnok wrote:
> ----------------------------Original message----------------------------
> >At 16:54 29/7/99 EDT, you wrote:
> >----------------------------Original message----------------------------
> > T'would make a fascinating "read" if anyone wants to try to explain why
> 3-posts should be better -- I'm sincerely curious!
> >Ellen Baker
> Hello Ellen et al.,
> I wish to begin with the definitions in Euclid's Elements (not the
> company, the 2000+ year old book about geometry) where it is stated, "3
> points determine a plane". Now it's true that 4 points may also determine a
> plane, but they also may determine 2 planes, looked at in one way, or a
> tetrahedron, looked at in another. And I have seen many a kiln shelf (a
> plane), when loaded heavy enough and fired hot enough, turn into 2 planes
> (that is, break), just as predicted by old Euclid.
> I think there are mitigating circumstances. First, if you load your
> kiln perfectly: the floor of the kiln is a perfect plane; the posts are of
> exactly the same height; the wash on the shelves is perfectly even. Second,
> the load is not very heavy, and is not stacked very high, and the shelves
> are thick enough to have a large margin of strength. Then you can get away
> with a 4 point load.
> However, I have a friend up the road who was firing 4X4 relief
> tiles, stood on edge (heavy!), around 10 layers high, as I remember, and she
> was sloppy about cleaning shelves and wadding off posts, and in less than a
> year she had broken every shelf in her kiln. Using 4 posts per shelf.
> Whereas we fire 8X8 mural pieces, up to 4" thick, on edge, (even
> heavier), load them sloppy as children (industrial, you know: time is
> money), with unground glaze runs plastered over with kilnwash on the corners
> of the shelves, and posts that are only tiny points at the top, they're so
> battered, and virtually never break a shelf. Using 3 posts per shelf. And
> you should know this is a relatively big kiln, with a footprint of 24
> shelves, so we're often firing 96 or 120 shelves at a time. If we were
> breaking a lot, I'd be trying something new, you can bet.
> So there you go, my best argument, first theory and then practice.
> And you may also be interested to know that I have also built 3 point
> buildings on Alaskan permafrost, which heaves and sinks as it freezes and
> thaws, and tears traditional 4-or-more point buildings apart, whereas the
> 3-pointers are naturally, geometrically indestructable. I now live in a 3
> post house built on expansive clay, and after 10 years it is doing just
> fine, while all the buildings around me are crack city.
> Please note too that airplanes have 3 wheels, or possibly 6, but in
> pairs, and the lunar lander had 3 legs. There is a sound engineering reason
> for all this, and it all starts with Euclid's remarkable observation that 3
> points determine a plane, no matter how it tilts.
> So that's my vote: 3 points forever.
> Pedantically yours,
> Nikom in Thailand, where if it ain't raining the RH is 80%, and since the
> pots won't get dry I have nothing better to do than yammer away on the old