Cone Layout

[R W]

Any easy method to divide a cone layout into 12 equal sections.
Thank You.

[tigmusky]

I don't know if this will help. radius x 3.14 PI divide 12

daye

[madkaw284]

First of all, Do you know how to layout a cone?

[aevald]

Hello R W, if you already have the pattern drawn you likely have so many degrees of a circle to represent the particular pattern to make your cone. If you know this total degree number you can divide this number by 12 and using this number you can apply chord dimensioning to split your pattern into 12 equal parts. As an example: if your pattern requires 165 degrees to make your cone, divide that number by 12, the product is 13.75 degrees. Use the 13.75 degrees and input that information into the attachment that I will include with this post. The resulting answer will allow you to start at one end of your pattern and measure straight across from the starting point to a point straight across on the radius to locate a 13.75 degree division. Hope this makes sense and good luck. Best regards, Allan

[steel]

circ divided by 360 will give u the act measurement of one degree. then divide 360 by 12 then 12 times what ever 1 degree is gives u 1/12th

[aevald]

Hello Steel, I'm guessing here, but I believe he is trying to divide his pattern into twelve equal segments so that he can possibly use a pressbrake to form it to it's final shape. At least, that's the way that I read his post. Could certainly be wrong though. Best regards, Allan

[aevald]

I was going to try to add this to my first post, but I guess I don't have a grasp of what's required to do that, so here it is instead. It's an example of how I might go about dividing an existing pattern for a cone into 12 equal pieces to facilitate bending if using a pressbrake for forming. Hope this makes sense and helps. Best regards, Allan

[R W]

Hello Steel, I'm guessing here, but I believe he is trying to divide his pattern into twelve equal segments so that he can possibly use a pressbrake to form it to it's final shape. At least, that's the way that I read his post. Could certainly be wrong though. Best regards, Allan

Your right thats exactly what i'm after.

[Donald Branscom]

Cones are rolled - not folded on a press brake.
This discussion has not pointed out that the THICKNESS of the metal you are rolling into a cone is important.

Now for the real SECRET to welding a cone.
Not even the (I cannot print it, wish I could ) govt. agency knew this: The cone has to be welded on the inside FIRST. Then the outside - or it will be deformed. Just like a boat hull.

[aevald]

Hello Donald, I will respectfully disagree with your statement as to rolling vs. braking, many cones are rolled if you have that capability in your shop. I have seen a great number of them that have been broke as well, one piece if the size allows clearance for the dies, two or more pieces if the cone is long or if it is particularly large. Thickness can certainly have a bearing in many instances and also equipment available. Best regards, Allan

[drafterx]

Right on, I have Broke for easy layout and size goals, then run it thru the rolls for looks and lineup. :drinkup:

[steel]

RW do it my way forget the cord thing just take the circ divide by 12

[steel]

why would a cone only have 165 degrees and not 360? Hummm alway thought circiles had 360. Learn something new every day

[aevald]

Hello Steel, if you take a flat steel donut and remove a pie shape from it, it will become a cone when you bring the ends together. The more of the pie that you remove, the taller the cone becomes and the smaller the outer and inner diameters become. R W is dividing the actual pattern from the portion of the flat donut that will make his particular cone into 12 equal segments, thus, he isn't starting with a full 360 degrees, only a portion of the complete circle. Chord dimensioning will allow you to equally divide the part(however many degrees makes it up) into very precise divisions. If this sort of accuracy isn't required for whatever reason, you can certainly utilize other more speedy methods. Best regards, Allan

[steel]

Finding the cord is just another unnessary step.Once the pie is out whats left is the circ of the cone. Divide by 12 and that go for both circs, althought he didn't say the the top was cut off. not that it matters. Hes braking a cone not working for nasa. He asked for the esay way

[gordfraser]

To lay out the curved surface of a cone on a flat sheet:
draw a straight line that is equal to the length from the point of the cone straight down the curved surface to where it meets the circular base ( to the circumference of the base)

set a compass to the length of that line. center the compass at one end of the line and draw an arc from the other end of the line.

the arc should be as long as the circumference of the base of the finished cone.

then draw a straight line from the end of the arc to where the compass point was.

to divide it into 12 parts set the compass to half of the radius and divide out the arc that you drew.
might not be exactly half the radius, but you can adjust the compass one twelfth of the difference.

hope that is clear to all.

[steel]

Wow gotta make things difficult. Cut out the cone and mark off the incraments that u have gotten from dividing the circ . Hes making a steel cone !!!!

[R W]

Thanks for your replies. Just deleted this post .

[steel]

Wow.......

[R W]

Dia X 0.258819 = Length of Chords for 12 Spacings Around a Circle.
(Ref; Pipefitters Handbook)

[fdcmiami]

great illustration. not just cones but sections of cones also, we busted up lots of square to rounds out of 3/8 ths plate on large hydraulic press brakes. the better ones will have independent tonnage settings/ depth for left and right hand sides.

what's up with that you have to weld from the inside, there's a second piece of bad info.


we had to develop a lot of cones where the apex was thirty or forty feet out. guys would be laying out the arcs with string and soapstone. then, when TI came out with calculators (reasonably priced) that would allow you to input linear equations we could do it by solving for x and y; not long after that the programmable machines rolled in, laser and plasma and out to the field we went.

still need a guy that can field measure that last fitting on a run. say an offset rectangle to round; there's not many out there that can.

at least under the age of 50.

[Country Metals]

still need a guy that can field measure that last fitting on a run. say an offset rectangle to round; there's not many out there that can.

at least under the age of 50.

I can, it might take me a few minutes, but I'll get it done.

First, you order your ice cream with a waffle cone, then you eat all of the ice cream and use your razor knife and flatten out the cone and your all done!

[Rickster]

There is a Metal Layout Calculator that fits in your shirt pocket that will layout flat patterns for (Cones that are C/L or Offset), Square to Rounds, Round Elbows, Tee's at any angle including the hole layout and much more. It reads out in both Decimal and Fractional to the closest 1/32" of an inch. using a large Blk.& White screen. It comes with a 100 plus page Visual Manual for people that can read a drawing easier than they can read the written word like myself. You just transfer the dimensions the calculator gives you to your material starting with a BaseLine. You can copy a page from the Visual Manual to take out in the shop for reference if you don't know the Layout. It really speeds up a job and is mathematically DEAD ACCURATE and you don't need to know any math. It also has a lot of Utility programs like solving triangles,(90` & Oblique), Finding Arcs and Radius's, layout for a perfect Ellipse including the circumference,(Used for penetrating a deck or wall with a pipe at any angle) and much, much more. Its well worth looking at. The website is www.sheetmetallayoutcalculator.com

[Rickster]

[QUOTE=Rickster;766111]There is a Metal Layout Calculator that fits in your shirt pocket that will layout flat patterns for (Cones that are C/L or Offset), Square to Rounds, Round Elbows, Tee's at any angle including the hole layout and much more. It reads out in both Decimal and Fractional to the closest 1/32" of an inch. using a large Blk.& White screen. It comes with a 100 plus page Visual Manual for people that can read a drawing easier than they can read the written word like myself. You just transfer the dimensions the calculator gives you to your material starting with a BaseLine. You can copy a page from the Visual Manual to take out in the shop for reference if you don't know the Layout. It really speeds up a job and is mathematically DEAD ACCURATE and you don't need to know any math. It also has a lot of Utility programs like solving triangles,(90` & Oblique), Finding Arcs and Radius's, layout for a perfect Ellipse including the circumference,(Used for penetrating a deck or wall with a pipe at any angle) and much, much more. Its well worth looking at. The website is [url]www.sheetmetallayoutcalculator.com

99321

[OPUS FERRO]

R W - This is a geometric constant that anyone that requires layout should
internalize. I can't post illustrations, so I'll attempt an explanation. No math
is required for this operation, only a compass.

1) With a compass, swing the desired [radius] circle.

2) Next draw a long horizontal line thru the center (radius point) that extends
passed both sides of the circle [bisecting the circle].

3) Place the compass pivot on the intersect of the bisect line where it passes
thru the circle and swing lines, up and down, do this on both sides.

4) Draw a cord line between each of the 6 points scribed on the circle forming
a hexagon.

This is the epiphanial part where you hear the chorus, and why there is 360 degrees
in a circle. Any radius is the cord length of a hexagon - 6 sides x 6 = 36. Put 10
points between the cord to center point, and you get 360 degrees. To get a 12 point
cone, reset the compass smaller, and bisect each cord = 12 sides. Opus

[aevald]

Hello Opus, I believe this drawing might be a good base to start from for a cone layout.

[The_Blacksmith]

Oh, my goodness guys! The most basic layout, let's call this a cone/funnel... first year sheet metal apprentices learn "Sheet Metal Pattern Drafting by Daugherty, page 72. When you divide a circle into 30* increments... you end up with 13 points... hence 12 equal segments.