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Hyperbolic paraboloid (saddle) raising


#1

I am trying to find some on making hyperbolic parabolid
(saddle) forms and can find no . Heiki Seppa’s book
shows a poor illustration but there is no directions. There are no
tutorials. Michael Good just talks about anticlastic and synoclastic
raising which I know how to do, but am frustrated in not being able
to make the “saddle”. Any help out there?


#2

Bill Fretz has some amazing dvds teaching synclastic and anticlastic
raising. Otto Frei has the companion stakes and hammers kit
available. Denny Diamond

den


#3

Edith, I don’t know if these references would have what you want,
but here are some:


http://ganoksin.com/borisat/nenam/anticlasic-raising-michael-good.htm

Look up “The Making of the Ribbon Torque,” Brian Clarke (Ireland)
Allan Revere, The Art of Jewelrymaking…, pp. 122ff.
Tim McCreight (ed.), Metals Technic, p. 29ff
Lapidary Journal, Nov. 2003, p. 44 (anticlastic bracelet)
Jinks McGrath, Encyclopedia of Jewelrymaking Techniques, pp. 78-79
Lapidary Journal, July 2007

All the best,
Judy Bjorkman


#4

Hello edith, This is easily made as a wax carving and casting if you
are trying to be commercial. If you just want to have fun; back to
the hammers and work from the center out.

tom arnold


#5

Edith, It sounds like you are referring to ‘anticlastic’ forms (a
saddle shape) common on making cuff bracelets. Anticlastic forms are
also popular for making interesting artistic shapes as well.

This is not a difficult process. Check out Rio Grande where you will
find a very clear video on the process, the proper hammers and the
stakes needed to create these forms. Kevin Potter at potterusa.com
also has on his site. Some of these forms are made by
hammering and others are more easily done with a hydraulic press.
Cheers from Don in SOFL


#6

The hyperbolic paraboloid, saddle or Pringle’s potato chip, is one of
the more difficult shapes to make. Look at Heikki Seppa’s diagram. He
divides a square into quadrants, either from corner to corner, or
from side to side. The final shape is different depending on which
one you start with. In quadrants 1 and 3, forge the metal on a flat
steel bench block so that the edge curves outward away from the
center of the square. The cross-hatches on his diagram are the
hammer blows. Flip the blank over, and do the same for quadrants 2
and 4. Note that the blank is still flat when you are done. You have
merely stretched the edges. You need to keep up with the quadrants as
you raise the blank on a sinusoidal stake. 1 and 3 will curve toward
each other above the stake and 2 and 4 toward each other below the
stake. Final closure is via planishing against a round mandrel.

Remember to anneal early and often. 20 gauge or thicker for this one
because of the stretching.

Anticlastic cuffs and variations thereof are much easier and it
sounds like you have done these.

Good luck.

Emie Stewart


#7

There have been some good responses to your query. However, theres
been rather a lot of fancy words bandied about. forget these, What
is in fact hapening is your stretching metal, using a hammer and
supportive block of preferably hardened steel.

to make the fastest progress, just have a go on some 1mm thick
aluminium or copper.

I dont do that kind of work but yesterday, i thought Id have a go.
took an ali disk 2in dia, marked it with a pen into 4 quadrants, took
an ordinary carpenters cross peen hammer, and had a go. 20 mins later
I had your saddle shape. you need to do the same.

Experiment on metal that costs you virtually nothing, only your
time. And its a learning opportunity for you. Dont be afraid to hit
it!!.