# Bending offset



## ElectricalArtist (Jul 2, 2014)

Do you guys bend offsets this way? It says bend your first mark off the floor which is normal but bending the second mark this way ,especially with 1 inch seems preety hard with a short piece to grab on to and bend under the armpit. It would be easier if there is a stairs to use to bend on the floor but not in the air.


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## telsa (May 22, 2015)

Your technique may vary... as ones own weight is a significant factor.

I prefer to eyeball my offsets -- with the bender shoe facing the sky. 

Full quarter bends -- I bend with the shoe on the floor.

This works for EMT up through 1" -- and I'm going for speed.

If you're bending on an high specifications job ( NECA//IBEW ) and you're running IMC... then a power bender with all the trimmings makes sense.

[ Amazon 15.00 ]

Benfield Conduit Bending Manual

It's well worth the money. ^^^^


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## B-Nabs (Jun 4, 2014)

I make most of my bends in the air as well. Sometimes I even start 90s in the air and finish them on the ground, to aid in alignment. As for the example in the diagram, I would bent that the other way round, so that I had the longer piece of pipe to help with leverage. 

Sent from my SM-G920W8 using Tapatalk


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## ElectricalArtist (Jul 2, 2014)

B-Nabs said:


> I make most of my bends in the air as well. Sometimes I even start 90s in the air and finish them on the ground, to aid in alignment. As for the example in the diagram, I would bent that the other way round, so that I had the longer piece of pipe to help with leverage.
> 
> Sent from my SM-G920W8 using Tapatalk


But does that change the measurements? It says to pay attention to the orientation of the bender. Bend mark A on the floor facing away from B. And the second bend on B the arrow is facing the first mark. What do you do to keep the measurements the same


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## ElectricalArtist (Jul 2, 2014)

telsa said:


> Your technique may vary... as ones own weight is a significant factor.
> 
> I prefer to eyeball my offsets -- with the bender shoe facing the sky.
> 
> ...


I have the tom henry dvd and book which shows this same technique, does that book show different techniques?


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## Cl906um (Jul 21, 2012)

We have some benders with the rubber shoe on the handle side. It keeps the handle from skidding out and scratching finished floors.


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## Majewski (Jan 8, 2016)

I ask the apprentice to bend it because I lack simple skills.


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## Jhellwig (Jun 18, 2014)

ElectricalArtist said:


> But does that change the measurements? It says to pay attention to the orientation of the bender. Bend mark A on the floor facing away from B. And the second bend on B the arrow is facing the first mark. What do you do to keep the measurements the same


Technically no but in reality yes. A bend made on the floor tends to be tighter than one bent in the air so your measurements can come out being off. If you make bends on the floor versus that air you will measure a difference. The same can also happen if you are not consistent with your technique and foot pressure.

I tend to do all bends less than 90 in the air but I have long arms and big strong hands so I can closely replicate one bent on the floor.

A good technique to develope no matter what way you bend is to keep the preassure as close to the shoe as possible. You will get less wrinkle and constancy. You should be able to bend a 90 in 1/2 inch emt with only your foot for 90% of the bend.


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## cabletie (Feb 12, 2011)

It is very rare that I would be forced into having to bend it that way so close to the end. I can see that happening with a saddle, but not an offset. 

I think the point they are trying to make is that the radius is being bent away from the obstruction. Normally you would bend it the other way and start the bends closer to the end of the conduit, or just use the 36 inch measurement and cut some off later.


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## Cl906um (Jul 21, 2012)

Majewski said:


> I ask the apprentice to bend it because I lack simple skills.


Bending conduit is one of the last art forms we have. For exposed work, say rgc, I would be embarrassed to just let an apprentice do it. I would let a strong back help a journeyman, but not let make decisions where tight places require someone with experience to not screw every other conduit that goes up after without ease. It mostly makes a difference in industrial.


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## daveEM (Nov 18, 2012)

cabletie said:


> or just use the 36 inch measurement and cut some off later.




What are you going to do with all the little pieces?


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## Cl906um (Jul 21, 2012)

I was admiring a 3/4 conduit from the 1940s era that followed closely to a iron stairwell. It was on the inside off rotating with only three bends and 0 ericksons.i think someone said earlier that ericksons free work was a test of intelligence. Good conduit work is a hard operation to fake.


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## Cl906um (Jul 21, 2012)

cabletie said:


> It is very rare that I would be forced into having to bend it that way so close to the end. I can see that happening with a saddle, but not an offset.
> 
> I think the point they are trying to make is that the radius is being bent away from the obstruction. Normally you would bend it the other way and start the bends closer to the end of the conduit, or just use the 36 inch measurement and cut some off later.


Learn, and mark your bender to bend on centers of bends.


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## ElectricalArtist (Jul 2, 2014)

cabletie said:


> It is very rare that I would be forced into having to bend it that way so close to the end. I can see that happening with a saddle, but not an offset.
> 
> I think the point they are trying to make is that the radius is being bent away from the obstruction. Normally you would bend it the other way and start the bends closer to the end of the conduit, or just use the 36 inch measurement and cut some off later.


How would you position the bender to bend and offset like this? Which way do you face the arrow and what bend do you make first?


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## MechanicalDVR (Dec 29, 2007)

daveEM said:


> What are you going to do with all the little pieces?


Keep them at hand to throw at apprentices when they act up, of course!!!


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## PlugsAndLights (Jan 19, 2016)

daveEM said:


> What are you going to do with all the little pieces?


Goof around with them like they're kali sticks. Doesn't everyone? 
P&L


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## cabletie (Feb 12, 2011)

ElectricalArtist said:


> How would you position the bender to bend and offset like this? Which way do you face the arrow and what bend do you make first?


That would depend on a lot of things. What size pipe, what size offset, what degree bend, thin wall or heavy wall?

If you are talking about a hand bender like the picture, with 3/4" EMT, I would mark back 36" from the end of the conduit for the second bend. From there I would put a second mark back closer to the end of the conduit for the first bend. The distance to the second mark would depend on your degree of bend. I would put the long end of conduit over my shoulder, and put the bend mark closest to the end on the arrow. Pull it to your degree. Slide it to the next mark, and make the second bend. Depending on the amount of the offset and degree of bend, the pipe will shrink enough to get the radius off of the obstruction. If not trim it with your M12. If it shrinks too much, it's probably not a bad thing. 

If your trying to match an exsisting offset, or your running rigid, then I might do the math to figure in shrink and adjust for center of bend or distance to the bench mark. Guys used to put cheat sheets in their hard hats with the information they needed for the bender. Stuff like travel and take-up.

I made a few on my phone using Numbers (Excel). The spreadsheet is driven by the take-up and the gain. Adjust either and all the numbers readjust. I copy and paste the sheet and use it for different benders. I have it set up for the two size Chicagos and the 854 smart bender. I never use it. The RIGIDPRO App is much easier. Also notching your bender for center of bend takes out some of the math also


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## cabletie (Feb 12, 2011)

daveEM said:


> What are you going to do with all the little pieces?


When no ones looking I slide them on to someone's else's cart, unless the boss is giving bonuses for the most money saved, then I hold on to them. :huh::thumbsup:


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## varmit (Apr 19, 2009)

I always considered bending accurately more technique dependent, where a persons size or weight is not really a factor. I have always weighed less than 150 pounds and always could bend whatever was needed.

I prefer to bend with the conduit on the floor. I believe that, for most folks, this makes a cleaner bend. I have seen some folks that could make uniform bends in the air though. It is just a matter of what someone becomes accustomed to. 

It makes bending much easier, and faster, if you mark the center of the bender for the degree of bends you normally use. Using this method, you can place the conduit in the bender in either direction, and the bend will be correct.
as long as you mark, or eye ball, the center to center dimensions correctly.


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## nrp3 (Jan 24, 2009)

I ask the apprentice to do the bending because I know he's better.


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## rankin (Apr 14, 2015)

varmit said:


> I always considered bending accurately more technique dependent, where a persons size or weight is not really a factor. I have always weighed less than 150 pounds and always could bend whatever was needed.
> 
> I prefer to bend with the conduit on the floor. I believe that, for most folks, this makes a cleaner bend. I have seen some folks that could make uniform bends in the air though. It is just a matter of what someone becomes accustomed to.
> 
> ...


I always assumed the arrow was the end of the "straight" portion of the bend. When making offsets or box saddles that fit snug up to the obstruction, I use the arrow; when I'm doing a three point saddle, I use the center mark. Am I wrong?


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## TGGT (Oct 28, 2012)

rankin said:


> I always assumed the arrow was the end of the "straight" portion of the bend. When making offsets or box saddles that fit snug up to the obstruction, I use the arrow; when I'm doing a three point saddle, I use the center mark. Am I wrong?


That notch is the center of a 45* and only 45*. The star is the back of a 90*.


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## rankin (Apr 14, 2015)

TGGT said:


> That notch is the center of a 45* and only 45*. The star is the back of a 90*.


Right -- I'm talking about center marks that I've made myself. Whenever I get a new bender I always mark out the center of 30* 60* and 45* (the notch isn't always for 45*). But I only use those for three point saddles and matching existing conduit runs. I always thought if I used the center for a standard offset or box saddle, I'd have to guesstimate where to put my bend even after calculating shrink, because the center of the bend radius wouldn't sit as flat and snug on my obstruction as if I had used the arrow.

How I do it for a standard offset (on;y using the arrow): measure from the end of my run to the obstruction. Measure the rise. Calculate shrink. Calculate distance between bends.
First mark: from the end of the pipe to my obstruction + shrink.
Second mark: the distance between my bends.

Facing the end of the pipe I measured from, I bend the mark closest to the end of the pipe I measured from. Then I do the second bend, which is closest to the edge of the obstruction.

Put it in, admire it for five minutes, and take another 15 minute water break to reward myself for my productivity. :shifty:


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## TGGT (Oct 28, 2012)

rankin said:


> Right -- I'm talking about center marks that I've made myself. Whenever I get a new bender I always mark out the center of 30* 60* and 45* (the notch isn't always for 45*). But I only use those for three point saddles and matching existing conduit runs. I always thought if I used the center for a standard offset or box saddle, I'd have to guesstimate where to put my bend even after calculating shrink, because the center of the bend radius wouldn't sit as flat and snug on my obstruction as if I had used the arrow.
> 
> How I do it for a standard offset (on;y using the arrow): measure from the end of my run to the obstruction. Measure the rise. Calculate shrink. Calculate distance between bends.
> First mark: from the end of the pipe to my obstruction + shrink.
> ...


OIC.

I use center marks more often than not when bending offsets, kicks, and saddles. I generally do not place my bends so close to the obstruction unless there is an aesthetic reason. Unless I'm running rigid in a tight spot where I need to be precise, I'll guesstimate where to put the center of the bend closest to the obstruction (first bend usually), angles being considered.


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## Bird dog (Oct 27, 2015)

Ideal Bender Guide

http://www.licensedelectrician.com/Store/ID/Data/conduit_bender_guide.pdf

Klein
http://www.gridalternatives.org/sites/default/files/assets/Team Leader docs/ConduitBenderGuide.pdf


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## cabletie (Feb 12, 2011)

rankin said:


> I always assumed the arrow was the end of the "straight" portion of the bend. When making offsets or box saddles that fit snug up to the obstruction, I use the arrow; when I'm doing a three point saddle, I use the center mark. Am I wrong?


 The arrow is just a benchmark. There is some straight pipe between the benchmark and the beginning of the radius. Here is a formula to find how much that straight pieces is. 

BM to start of bend=Takeup - Radius - 1/2 of O.D.

On an Ideal hand bender that comes out to an 1/8". Pretty flush like you said. On a different bender it would be more. 

The length of the radius or developed length is also the amount of travel. 

D.L. = .01745 x Radius x degree of bend. 

So on 3/4" EMT with an Ideal hand bender at 30 degrees that would be 3-3/4" or 1-7/8" to the homemade notch. So it should be 1-3/4" from bench mark to center of bend.


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## Gnome (Dec 25, 2013)

daveEM said:


> What are you going to do with all the little pieces?


Wind chimes


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## telsa (May 22, 2015)

cabletie said:


> That would depend on a lot of things. What size pipe, what size offset, what degree bend, thin wall or heavy wall?
> 
> If you are talking about a hand bender like the picture, with 3/4" EMT, I would mark back 36" from the end of the conduit for the second bend. From there I would put a second mark back closer to the end of the conduit for the first bend. The distance to the second mark would depend on your degree of bend. I would put the long end of conduit over my shoulder, and put the bend mark closest to the end on the arrow. Pull it to your degree. Slide it to the next mark, and make the second bend. Depending on the amount of the offset and degree of bend, the pipe will shrink enough to get the radius off of the obstruction. If not trim it with your M12. If it shrinks too much, it's probably not a bad thing.
> 
> ...


Too much information.


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## fisstech (Feb 2, 2013)

i rarely bend off the floor. it just seems awkward to me. it's mostly personal preference.

unless we're talking 1 1/4. you bend that stuff off the floor haha


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## Jarp Habib (May 18, 2014)

Second bend gets started in the air but finished on the ground. I don't like trying to start the second bend with the first holding the rest of the conduit & bender up off the ground a few inches, I know a few guys who pull it off but for me it's a recipe for sudden dogleg, wrinkles, bowed straights and angle taken out of the first bend.

For bending on the short end of the stick, either give yourself some fudge factor and keep bending off the arrow (flipped around ) or get comfortable with shrink and center bending and nail it precisely.


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## B-Nabs (Jun 4, 2014)

I've never really used the center method, simply because I wasn't taught it. I'll have to try it some time. If I need to make a bend where it was easiest to measure in one direction, but it will be easier to bend in the other, then I will move the mark the distance that the bend I'm going to make would take up. I determine that by taking the 90* take-up of the bender (eg. 6" for a 3/4" bender), and multiplying it by the bend I'm going to make, divided by 90. So, if I'm going to make a 30* bend in 3/4" EMT, I would just multiply 6" x (30/90) = 2". Move the mark 2" and flip the bender over, and the bend should end up in the same place. And before anyone says it, yes I can see that this is essentially a more convoluted way of using the center of bend method. Like I said, I'll have to try that some time.


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## TGGT (Oct 28, 2012)

B-Nabs said:


> I've never really used the center method, simply because I wasn't taught it. I'll have to try it some time. If I need to make a bend where it was easiest to measure in one direction, but it will be easier to bend in the other, then I will move the mark the distance that the bend I'm going to make would take up. I determine that by taking the 90* take-up of the bender (eg. 6" for a 3/4" bender), and multiplying it by the bend I'm going to make, divided by 90. So, if I'm going to make a 30* bend in 3/4" EMT, I would just multiply 6" x (30/90) = 2". Move the mark 2" and flip the bender over, and the bend should end up in the same place. And before anyone says it, yes I can see that this is essentially a more convoluted way of using the center of bend method. Like I said, I'll have to try that some time.


If you bend any 3 or 4 point saddles on any machine bender you'll love the center method. Start on one end and just bend, move forward, check dog, bend repeat until done. No flipping the conduit around to face a different direction.

Works on a hand bender too.


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## B-Nabs (Jun 4, 2014)

TGGT said:


> If you bend any 3 or 4 point saddles on any machine bender you'll love the center method. Start on one end and just bend, move forward, check dog, bend repeat until done. No flipping the conduit around to face a different direction.
> 
> Works on a hand bender too.


The only machine my company has is a Greenlee flip top hydraulic. I'm not sure how I would set up for the center method on that thing. And I would pretty much do anything to avoid bending a saddle in pipe that big anyway (it only does 1 1/4", 1 1/2", and 2", and 90% of the time we use it for 2").


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