Electron_Sam78
Senior Member
- Location
- Palm Bay, FL
How do you meassure the radius of a bend in conduit or cable? I used to know but it's since vacated my mind. Use it or lose it...
measuring the radius of bends
- Thread starter Electron_Sam78
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ohmhead
Senior Member
- Location
- ORLANDO FLA
How do you meassure the radius of a bend in conduit or cable? I used to know but it's since vacated my mind. Use it or lose it...
Well bend a 90 deg bend on any pipe size .
lay it on the floor flat the inside straight edge from start of bent pipe to end of bent pipe of that 90 is your radius of your bend .
Thats measured on the inside of that conduit bent !
developed length for a 90 deg bend = 1.57 x Radius
Half the diameter of anything is the radius .
DL/1.57 = RADI
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cadpoint
Senior Member
- Location
- Durham, NC
Since you said conduit and cable it varies a little between what type of application your using shielded and or unshielded see, Article 300.34
Doug S.
Senior Member
- Location
- West Michigan
Trig, or a string. Depending on if it's on paper or on the floor.
cadpoint
Senior Member
- Location
- Durham, NC
How can you qualify that, please expand on your statement, the Code needs to be met per the application, and that's a sudo shot from the hip reply, In My Opinion... Granted not many are use to going long a Bend but hey ...
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String can be used just like your tape measure....Put the dumb end (zero point) of the tape at the center of the circle (radii), then however many inches are required, scribe that line for a print for your pipe!
If you need legal minimums, see Chapter 9 table 2.
If you need legal minimums, see Chapter 9 table 2.
Doug S.
Senior Member
- Location
- West Michigan
Sorry? It was a simple answer, inferring the solution was simple. Nothing pseudo about it.
The trig. ( or a variant of ) was already shown. Smart $ gave a nice drawing. If you are board I can show the 52? other ways I know how to analyze an arc.
The options for a string are pretty much limitless too. Finding a center pt w/ a square is easy, then the radius is right in front of you. If you are doing cable lay out, a center point, some string, and some chalk or a pencil work great.
cadpoint
Senior Member
- Location
- Durham, NC
Sorry? It was a simple answer, inferring the solution was simple. Nothing pseudo about it.
The trig. ( or a variant of ) was already shown. Smart $ gave a nice drawing. If you are board I can show the 52? other ways I know how to analyze an arc.
The options for a string are pretty much limitless too. Finding a center pt w/ a square is easy, then the radius is right in front of you. If you are doing cable lay out, a center point, some string, and some chalk or a pencil work great.
Your right this is a simplied example of "how to".
I've never remembered anything remoting that simple as a geometry problem of this nature that I didn't have to reference a calculus book or a machinery handbook to make a determination as to the exact problem I need to proof for.
Forgive me if I over stated yours or even my understanding of gaining a correct answer in the simplest sense.
If one where to look up "circular segment"
There's seven equations that can be used to find out the various aspects of a circular segment. In this case this could be the center line the inside of the conduit to obtain the chord length shown as "c" here or the length of the arc, s. In respects to this thread one could use this as the inside edge of a bending radiaus
I've lost my main CPU, printer/scanner, and my acsii (this mini will not allow it use here) :\ (oh well)
So bear with me, one would only need to use one or two equations with some known quanties and go foward.
A= area ( the total shaded area )
s= length of arc
*= angle in degrees ( sorry, again I can't reproduce that symbol here)
R= is the radius
c= chord
s = 0.01745 R *
*= 57.296 s / R
c = 2 x the sq root of h(2r - h)
h = r[1 - cos(* / 2)]
h = r - .5 x the sq root of 4r sq'd - c sq'd
R= c sq'd + 4h sq'd / 8h
A= .5[rs - c(r - h)]
Enjoy...
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