View Full Version : Cone development etc
08-08-2009, 07:25 AM
Just found this lovely little free download on a U.K. welding forum and hope some of you guys cansmake some use of it,So simple for developing cones/cylinders with straight or angled ends, Enjoy! If it's been posted before Sorry.
11-05-2009, 10:09 PM
I found that one myself not long ago when I was searching for a cone calculator. I haven't used it yet, have you used it Gordon?
11-06-2009, 06:37 AM
Only used it once to fab up a funnel for my son to use, He runs a couple of Unimogs and road trucks on veg oil and needed a decent size funnel for hand pouring fuel cans into the mogs in the field,
11-07-2009, 10:48 PM
LOL, that's why I was looking for an online program to calculate a cone, I was wanting to make a funnel. I used to know how to figure one out.....back in HS metal shop.....of course that was 30+ years ago :)
I'm passing on 40 yrs o'hard knocks "the easy way"
Discounts for WW members
Can I do this here?
01-14-2010, 03:10 PM
here are two way to develop cones, right frustrums. off set cones a little more difficult to do with line work; triangulating to solve for true lengths.
01-14-2010, 03:13 PM
well now, that is quite a mess i just posted, will have to try that again and get some better resolution. i think the layout for a simple cone using radial line is fairly clear. the other two with the math require a little more definition. sorry, they looked ok when i scanned them.
01-15-2010, 04:15 PM
A quick and easy formula for finding the apex for a frustum of a cone is:
Large D of frustum - Small D of frustum = X,
(Desired Height of frustum) (Large D of frustum) = Y,
Y / X = N,
N = length from base of cone to apex of cone.
Example: need a bucket with a 12" D opening, 9" D bottom, 9" in height.
12" - 9" = 3"
(9") (12") = 108"
108" / 3" = 36"
Using the Pythagorean theorem you can then determine the "true length" of the cone to begin to lay it out. You now know that you will need a trammel or dividers that can span 36 1/4" to be able to layout the cone and make the frustum.
01-15-2010, 04:31 PM
If you are able to scribe the necessary size circle for the cone the fastest and easiest way to layout the frustum is:
Scribe a line on the metal and establish a center point for the cone,
Scribe a circle using the "true length" of the cone using the center point,
Measure from the edge of the circle just scribed toward the center and mark the "true length" distance between the large D and the small D,
Set your dividers or trammel to the distance from the center to the new mark and scribe another circle,
Take the differences between the circumferences in the circles scribed and the circumferences of the circles desired,
Using the scribe line first established as a reference point measure, with a flexible ruler, along each circle the difference in circumferences for each respective circle and mark this distance,
Connect these points with the center and add any amount needed for seams,
The pie piece that was now formed can be cut out leaving the rest to make the desired cone.
01-15-2010, 06:22 PM
I misspoke in my last post. That is not the fastest and easiest method for laying out a frustum of a cone, but a fast and easy way if you are using dividers or trammels. The fastest would be using triangulation.
01-16-2010, 04:41 PM
Try this one, its free but register after 7 days
03-22-2011, 10:29 AM
Don't forget to leave some extra material to account for the flats on the end. I don't suppose this would be a problem with 24 gauge, but it's a problem with just about anything you have to bump form or roll.
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