# 30 degree offsets



## william1978 (Sep 21, 2008)

I thought you were conduit Phil???????:blink::shifty:


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## mattsilkwood (Sep 21, 2008)

On a short offset like that I like to use 10s. It makes it easier to pull.


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## Benaround (May 5, 2009)

Phil,

If you need a 10" offset, using 30deg. bends, you need 20" between bends.

Is that your question ?

Ok, the smallest offset would be the measurement from the arrow on the

bender to the front of the bender.


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## 480sparky (Sep 20, 2007)

It's all just math. However, you're thinking it's a linear relationship, and it's not.

If the take-up of ¾" EMT is 6", then you could make a 360° circle with a 6" radius.

So what would the circumference be? Pi*r*2. 3.14*6*2. 3.14*12. Or 37.68".

So a 360° circle is 37.68" in circumference. From that, you can calculate how much of that is used in each 30° of arc. Double that for an offset.


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## Conduit Phil (Nov 19, 2009)

480,

Been a while since math class... 360/30=12. So there are 12 30 degree arcs in a circle.

37.68/12=3.14

3.14 is the minimum offset? Not sure why you'd double it. You are kicking it one direction and then back the opposite.

Thats close to 4 and the guide on porcupinepress.com says "30º bends are too great with most hand benders for offsets less than 4" center to center."


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## Speedy Petey (Jan 10, 2007)

Conduit Phil said:


> 3.14 is the minimum offset? Not sure why you'd double it. You are kicking it one direction and then back the opposite.


 Because using 30 deg bends you double the offset for your bend points. Using 45 deg bends you use 1.8 times the desired offset.






Conduit Phil said:


> Thats close to 4 and the guide on porcupinepress.com says "30º bends are too great with most hand benders for offsets less than 4" center to center."


Huh?? 
You take the conduit out of the bender and turn it around? That is not how most people do it. Not unless you have to that is.


Heck, using 3/4" I cannot see how it would be physically possible to get bends closer than roughly 4". :001_huh:


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## knowshorts (Jan 9, 2009)

Speedy Petey said:


> Because using 30 deg bends you double the offset for your bend points. Using 45 deg bends you use *1.8 times* the desired offset. :001_huh:


What kind of bender do you have? I've always used 1.41.


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## 480sparky (Sep 20, 2007)

Conduit Phil said:


> 480,
> 
> Been a while since math class... 360/30=12. So there are 12 30 degree arcs in a circle.
> 
> ...



You double it because, well, you need two bends to make an offset.


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## Bob Badger (Apr 19, 2009)

480sparky said:


> You double it because, well, you need two bends to make an offset.


Stop confusing me with such facts. :laughing:


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## 480sparky (Sep 20, 2007)

Bob Badger said:


> Stop confusing me with such facts. :laughing:



OK, Bob. Just for you, I'll let you make 2½ bends.:whistling2:


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## Bob Badger (Apr 19, 2009)

480sparky said:


> OK, Bob. Just for you, I'll let you make 2½ bends.:whistling2:


Bending takes to much time anyway just 'bow and go'.:jester:


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## jwjrw (Jan 14, 2010)

Bob Badger said:


> Bending takes to much time anyway just 'bow and go'.:jester:


 
Nah just warm up the pvc blanket and shape as needed:jester:


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## mattsilkwood (Sep 21, 2008)

Bob Badger said:


> Bending takes to much time anyway just 'bow and go'.:jester:


 You must really get around. I've seen your work all over the place.:jester:


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## varmit (Apr 19, 2009)

Conduit Phil said:


> How would one figure out the minimum size offset you can make using the 30 degree bends? Obviously there has to be a minimum size because of the size of the bend. Is there a chart?
> 
> If we use 3/4" EMT as an example, the takeup for a 90 bend is 6 inches. So 1/3 of that would be a 30 degree bend, or 2 inch takeup. Is that the same as the offset amount?


Hey Phil,

There is no chart that I know of. The min. offset would vary with each size conduit and bender type.

To determine the minimum offset on a specific bender/ conduit size, Multiply the amount of offset desired by the cosecant of the angle desired: (30 deg = 2; 15 deg = 3.86; 10 deg = 5.76). This measurement must be enough to line up the second bend mark on the correct center mark for the angle desired- (this will NOT be the star mark for a 90 deg stub), and have enough conduit to have the first bend mark about one pipe diameters past the end of the shoe. This is way easier to demonstrate than to explain.

I always mark my hand benders with the center marks for 5, 10, 15 and 30 degrees. This makes bending faster, more neat, and easier to match multiple runs.

On my usual 3/4 ENT bender, a 2 inch offset on 30 degrees is the minimum offset. I would normally bend any 3/4 EMT offset, less than 3 inches, on 15 degree or less bends. It looks neater and is easier to pull wire. 

Does anybody remember the days of concentric bending?


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## rlc3854 (Dec 30, 2007)

varmit said:


> Hey Phil,
> 
> Does anybody remember the days of concentric bending?


 
What's a do hickey:laughing::laughing:


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## Frasbee (Apr 7, 2008)

On that note, does everyone prefer 30 degree offsets?

After this job, I'm beginning to rethink my use of them.

Granted, they ran 1/2'' pipe where solid 12's and 10's were being pulled through, but to prevent pulling fiascos like that in the future, I'm considering stepping it down to at least 22 1/2 as a baseline.


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## varmit (Apr 19, 2009)

Frasbee said:


> On that note, does everyone prefer 30 degree offsets?
> 
> After this job, I'm beginning to rethink my use of them.
> 
> Granted, they ran 1/2'' pipe where solid 12's and 10's were being pulled through, but to prevent pulling fiascos like that in the future, I'm considering stepping it down to at least 22 1/2 as a baseline.


I prefer 15 degree offsets myself, as long as they are not huge. They do make wire pulling a lot easier, especially if I am working alone.


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## Speedy Petey (Jan 10, 2007)

knowshorts said:


> What kind of bender do you have? I've always used 1.41.


Duh. :icon_redface:
I knew that but wrote it wrong anyway.


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## RIVETER (Sep 26, 2009)

Frasbee said:


> On that note, does everyone prefer 30 degree offsets?
> 
> After this job, I'm beginning to rethink my use of them.
> 
> Granted, they ran 1/2'' pipe where solid 12's and 10's were being pulled through, but to prevent pulling fiascos like that in the future, I'm considering stepping it down to at least 22 1/2 as a baseline.


I like the 30 degree bends. As long as you don't give into the temptation to overfill the conduit it should be no problem. Teaching others the way around a Chicago bender is easier and the learner will remember that, and how to figure the gain and the loss of that bender, and how much loss you have to figure into the calculations to be able to cut and thread a straight piece of pipe before bending a 90 degree and an offset on the same piece. Just my opinion.


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## Adam12 (May 28, 2008)

Conduit Phil said:


> How would one figure out the minimum size offset you can make using the 30 degree bends? Obviously there has to be a minimum size because of the size of the bend. Is there a chart?
> 
> If we use 3/4" EMT as an example, the takeup for a 90 bend is 6 inches. So 1/3 of that would be a 30 degree bend, or 2 inch takeup. Is that the same as the offset amount?


Take a scrap piece of pipe and figure it out.


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## Southeast Power (Jan 18, 2009)

Frasbee said:


> On that note, does everyone prefer 30 degree offsets?
> 
> After this job, I'm beginning to rethink my use of them.
> 
> Granted, they ran 1/2'' pipe where solid 12's and 10's were being pulled through, but to prevent pulling fiascos like that in the future, I'm considering stepping it down to at least 22 1/2 as a baseline.


I try to use 30 degree bends out of pure laziness.
The bender handle is straight up for a 30 degree bend so I dont have to look.
You just double the distance for the offset.


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## nick.pei (Jun 15, 2009)

Conduit Phil said:


> How would one figure out the minimum size offset you can make using the 30 degree bends? Obviously there has to be a minimum size because of the size of the bend. Is there a chart?
> 
> If we use 3/4" EMT as an example, the takeup for a 90 bend is 6 inches. So 1/3 of that would be a 30 degree bend, or 2 inch takeup. Is that the same as the offset amount?


Here is a chart/guide which you can downlaod.

http://nickmacdonald.com/etwf/BendingRaceways.pdf


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