1. A friend had asked me to make two cone ornaments to replace some broken ones. It was a really great exercise in cone theory. And, allowing for material thickness. I know if I did this again I would be better prepared for some of the effects created by different type joints. When trying to match an existing object that may have slight hand made adjustments.

It is amazing how the cone and funnels workout from a vertex created by their finished sides, extended to an intersection.

You basically just calculate the circumference of the finished cone, from the diameter, and draw an arc the length of the circumference, from the imaginary vertex of each funnel. Created by the finished sides extended to an intersection. You add an extra tab to solder them together. And you have your cones and funnels.

I have some really great old literature on making all these kinds of strange eccentric and concentric cones. If anyone is interested.

Sincerely,

William McCormick

2.

3. I've made duct reducers, not so perty or exacting as your ornaments though. When I've had to form a "Y" with cones or odd angles I chicken out and creep up on the ellipse with cardboard.

Want a quick patina recipe that does not involve beer?

4. William,
although this makes reference to cones and conics, I feel it is somewhat out of place in Mathematics. It might be better under Experimentation or General Discssion, and it could well get more hits in the latter. What do you think?
Ophiolite

5. Originally Posted by Ophiolite
William,
although this makes reference to cones and conics, I feel it is somewhat out of place in Mathematics. It might be better under Experimentation or General Discssion, and it could well get more hits in the latter. What do you think?
Ophiolite
Oh wow, I thought for sure with the hundreds of calculations done either by me or the cadd program it would belong in the math department. But what ever you think is best.

I finished up the other one tonight.

Most people do not try this at home because they are afraid of the math to be honest with you. I thought I might highlight that it is just a bunch of math.

Thanks for the compliment Pong.

Pong a"Y" with cones might give anyone a hard time laying it out by hand. Ha-ha. I have trouble with set transition elbows some mornings. Ha-ha.

But if you use the old clock layout, it should be a snap. I have never laid out a "Y" cone. However it really should be easy using the old layout methods. You would need the two views to do it. A plan view if the cones are running horizontal and a look into the crotch view.

Sincerely,

William McCormick

6. Most people do not try this at home because they are afraid of the math to be honest with you. I thought I might highlight that it is just a bunch of math.
or because a decent CAD user could knock it out in a few minutes. but you could be right, (always a first time)

7. Originally Posted by organic god
Most people do not try this at home because they are afraid of the math to be honest with you. I thought I might highlight that it is just a bunch of math.
or because a decent CAD user could knock it out in a few minutes. but you could be right, (always a first time)
Unless the fellow is an experienced sheet metal guy. Most often a fellow will not even make it to the math. Because they do not know how to measure or what to measure. That is the truth. In my later years I learned a few tricks of bending metal, extrusion and structures, that in my younger days no matter how smart or math savvy I was. I would never have been able to just lay that out. Without turning it into a dreadful ordeal. Of very painful unforeseen errors.

But once you see the basic principle in play, and why and what is important. Then you can apply math or cadd to it in seconds.

I made this video for the General Cadd forum. But it shows the rather simplistic way you lay this out. It is really a great exercise in mathematics, and logic.

http://www.Rockwelder.com/Flash/Conehenge/Conehenge.htm

Basically you swing an arc to the finished objects side view, to an imaginary vertex to create the proper sized cut piece.

Sincerely,

William McCormick

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