[TheForge] eliptical rings on a cone mandrel?

[Ries Niemi]

>
>> Your father machined this on his elliptical lathe, right?
>>


I am assuming you were joking- but, there are, of course, elliptical 
lathes.
Ornamental turners use elliptical chucks to turn odd shapes- not simple 
ellipses, but much crazier stuff.
Rose engine lathes will turn all kinds of shapes you would never 
imagine- check out some of the stuff these guys do-
http://www.pledge.co.uk/

This whole idea of making ellipses on a cone- it seems theoretical to 
me.
I make ellipses from time to time, and much quicker, for me anyway, is 
to make a circle, weld it together, then tweak it manually on the 
hossfeld bender. I can do an eyeball quality ellipse in less than 5 
minutes.
For more precision, which I have never needed, I would drag out my old 
OMICRON ELLIPSOGRAPH- a great drafting tool from the 60's. It is an 
ellipse generating tool, which will draw ellipses in any max and minor 
dimensions, from about 2" to 12". I would draw one with that, then blow 
it up to the desired size with my overhead projector, then using a big 
paper pattern, shape the ellipse to match the pattern. For onsies, I 
would be willing to bet I could hand tweak a circle faster than you 
could make on with a cone, and my size limitations on the hossfeld 
would be anywhere from 3" major diameter to maybe 15 feet- much bigger 
than that, and I would have to move some bolted down tools in the shop, 
and it would take some assistants to do it.

I use a combination of expensive power machines, and years of 
experience with hand processes- and as a result, I dont even have a 
cone. They look purty, but I doubt I would use one much. The hossfeld 
will make perfect circles in all kinds of shapes of material, from 
about 1" od up to 24 feet od.
I also have power rolls that will roll up to 2" pipe or 2" angle, in 
theoretically up to infinite OD's. I can make ovals by rolling defined 
radius half circles on each end, with straights in the middle- have 
done a bunch of these.

There is an old stage hands maxim-
" never lift anything you can drag
never drag anything you can roll
never roll anything you can leave where it is"

similarly, in blacksmithing, I would say never heat up anything you can 
do cold.
I cold bend stuff all the time, with more precision, and faster, than 
you can hot form something over the horn of the anvil, or on a cone.
Ellipses are a great example of something faster and easier done cold.

Ries Niemi
Industrial Artist

http://www.RiesNiemi.com