need help

1

whats the whole answer

0.161

ok but what does tan stand for in the formula

Tangent.

thats r+t,so whats the rest of the formula for.the .161 is right

This is getting a bit basic. Tan is a trigonometric function, short for tangent. In a right-angled triangle, the hypotenuse is the long side, opposite the right angle. With respect to either of the other angles, opposite is what it says, adjacent is the third side. Tan of an angle is the ratio of the opposite side to the adjacent side.

If you take a right-angled triangle in which the other 2 angles are each 45°, for either 45° the opposite and adjacent sides are equal. So tan 45° = 1. So the answer = 1*(r+t) = 0.161

Cheers.........Codey

thank you ,that helps

what if the angle is 60

A 30, 60, 90° triangle has sides 1, 2, √3 (or any multiple). I'll leave you to work out which is which and that they satisfy Pythagoras's theorem.

It means tan 60° = √3 = 1.732. Alternatively you could use a tables or a pocket calculator. If you're on Windows, there is a calculator in Accessories.

Cheers........Codey

Hello Guest

Looking at recent posts I realised I told you wrong, sorry. If the angle = 60°, you're looking for tan 30°, not tan 60°.

Tan 30° = (√3)/2 = 0.866

Codey

Angle/2 = 90/2 = 45deg.

tan(45) = 1.

1 * (0.125 + 0.036) = 0.161

Regards JD

Bend Allowance = Angle * (PI / 180) * (Radius + K-factor * Thickness)

Outside Set Back = tan (Angle / 2) * (Radius + Thickness)

Bend Compensation = Bend Allowance – (2 * Set Back)
angle=90

radius=.125

k-factor=.42

thickness=.036

whats the anwser

( 0.125 + ( 0.42 * 0.036)) or ((0.125 +042) * 0.036)?

Bend Allowence = 90 * (3.1416/180) * ( 0.125 + ( 0.42 * 0.036)) = 0.2201

normal sign convention. 0r

Bend Allowence = 90 * (3.1416/180) * ( 0.125 + ( 0.42 * 0.036)) = 0.0308

Outside Set Back = 1 * (0.125 + 0.036) = 0.161

Bend Compensation = 0.2201 - ( 2 * 0.161) = -0.102.

Regards JD,

what if the angle was 70. what i don't under stand is the outside set back formula.is it always 1

To be able to vary the angle one would need to know what the logic is, is the above formula in regard to, Bends in trance mission lines? as 90deg is part of the maths logic? I am not familiar with the logic and would be fumbling around in the dark along with you. but would refer you to this web site.

Regards JD.

I bend metal for a living,Inside Set Back = tan (Angle / 2) * Radius.If i have a different angle,other than 90,How do i calculate.I'm not to smart with this stuff,just starting to learn.And nobody at work will share info,not like the old days,when people helped.

Are you referring to sheet metal work as referred to at this site

And I see the problem you refer to is at this site

Regards JD.

yes but it does not tell me much

Bend Allowance

– The length of the arc through the bend area at the neutral axis.

Bend Angle – The included angle of the arc formed by the bending operation.

Bend Compensation – The amount by which the material is stretched or compressed by the bending operation. All stretch or compression is assumed to occur in the bend area.

Bend Lines – The straight lines on the inside and outside surfaces of the material where the flange boundary meets the bend area.

Inside Bend Radius – The radius of the arc on the inside surface of the bend area.

K-factor – Defines the location of the neutral axis. It is measured as the distance from the inside of the material to the neutral axis divided by the material thickness.

Mold Lines – For bends of less than 180 degrees, the mold lines are the straight lines where the surfaces of the flange bounding the bend area intersect. This occurs on both the inside and outside surfaces of the bend.

Neutral Axis – Looking at the cross section of the bend, the neutral axis is the theoretical location at which the material is neither compressed nor stretched.

Set Back - For bends of less than 180 degrees, the set back is the distance from the bend lines to the mold line.

This is as much sense I can make of it at the moment, the results of the formulas don't mean much to me at the moment?

Regards JD.

ok,thanks

As you may or may not know, the tan of an angle is the ratio of the the two smaller sides of a 90deg triangle. So as you can see on the left sketch the radius+thickness is equal in length to the set back at 90deg, or set back/radius + thickness = 1, or tan 45deg = 90deg/2.

The right hand sketch shows a bend of an angle of 60deg, therefore the ratio of the sides is set back/radius + thickness = 0.5774 or tan 30deg = 60deg/2.

Hope this helps.

Regards JD.

Hello JD

From original post, I assumed r was the radius of the pipe (or plate or whatever) not the radius of the bend. Guest, which is correct? It affects the formulas!

Cheers......Codey

radius of the bend

where did you get pics

Drawn by myself on auto cad,

Sketch tan = 1 (90/2)

Tan = 0.577 (60/2)

tan = (set back) / ( radius + thickness)

Regards JD.

i need to put a hole in the center of the radius befor being bent how much do i add to the bend line to get to the center of the radius when flat