Hey all,
I have a unique question that maybe someone can help me with. Plasma cut some cone halves the other day and then they were to be step bent and welded together. I have attached a PDF of the flat layout and my callouts. Wouldn't let me attach DXF as the file is too large. The deeper cone turned out fine but the shallow cone did not. The press brake operator just ended up guessing how many degrees each bend should be and luckily it worked out. I later realized that my degree callout technically only works if its a true cylinder.
My question..... How do you figure degree-per-bend on a cone based on the angle it tapers?
Any help would be greatly appreciated
Thanks,
Levi
Step Bending Cones
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leviticus78
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Step Bending Cones
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cypher
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Re: Step Bending Cones
divide 180 by how many bends you have. your example that you have there is for half a cone correct? so therefore if you were to bend all 24 bends 7.5 deg you end up with a cone that goes half way around or 180 deg 
now bend placement is divided equally throughout the distance of each side. Your deg call outs should have worked because you are moving the same distance in deg around the circle in degrees, regardless of the size
now bend placement is divided equally throughout the distance of each side. Your deg call outs should have worked because you are moving the same distance in deg around the circle in degrees, regardless of the size-
leviticus78
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- Joined: Mon Oct 25, 2010 4:41 pm
Re: Step Bending Cones
That process works for a cone that tapers slightly to moderate.
For a cone that tapers drastically the "divide by 180" method gives too much degree per bend. If you had a cone that tapers from say 40" down to 5" and is only 12" tall the 180 method doesn't work.
I still haven't found any info regarding the changes in math that need to be made for a cone of this type so I do appreciate any and all input that you all can provide. Be assured if I do hear anything I will promptly post it here.
For a cone that tapers drastically the "divide by 180" method gives too much degree per bend. If you had a cone that tapers from say 40" down to 5" and is only 12" tall the 180 method doesn't work.
I still haven't found any info regarding the changes in math that need to be made for a cone of this type so I do appreciate any and all input that you all can provide. Be assured if I do hear anything I will promptly post it here.
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WILSPEC
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Re: Step Bending Cones
Leviticus78:
The degree method should still work, but it is critical that the bend lines are precisely located and the brake operator bends exactly on the lines. A particular challenge with bending two radii on a brake is allowing for springback, which will be different for the small & large ends of the cone unless the bottom die width is less than the bend line spacing on the small end.
I don't know the thickness of your material, but do you have access to a plate roll ? A roll can produce consistent curvature for both radii, and using incremental adjustments allows you to "sneak-up" on the desired end result.
Good luck,
WILSPEC
The degree method should still work, but it is critical that the bend lines are precisely located and the brake operator bends exactly on the lines. A particular challenge with bending two radii on a brake is allowing for springback, which will be different for the small & large ends of the cone unless the bottom die width is less than the bend line spacing on the small end.
I don't know the thickness of your material, but do you have access to a plate roll ? A roll can produce consistent curvature for both radii, and using incremental adjustments allows you to "sneak-up" on the desired end result.
Good luck,
WILSPEC
