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Thread: Conduit Bending 101

  1. #46
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    Charley, that level is something that didn't make it into my tool bag until close to retirement. I'm not sure when it became readily available, but I didn't see it until sometime in the early 2000's. There were a couple of guys I met on the job over the years who had something similar that was made by an electrician and was sold through mail order (before the Internet took off). It was extremely precise. Maybe Klein bought the patent from that guy.

    There's another feature on that level that helps prevent a dog in the pipe. Like when you bend an offset, lay it on the ground, and find the short end rises up off the ground. Of course, the field terminology for that feature is called a "no-dog". When bending with a machine, you insert the end of the level into the pipe and tighten the thumb screw, making sure one of the bubbles reads level. You make your first bend, roll the pipe 180 until the bubble you used is level again, and make your second bend. That eliminates the dog in an offset or saddle.

  2. #47
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    Kicking A 90

    Adding A Kick To A Pipe

    Sometimes it's better to kick a pipe rather than try to make an elaborate bend. In this case, we want to kick a 90.


    First thing you want to do is make sure the 90 is level. To do that, let the toe of the bender sit flush on the floor. The toe has "outriggers" that you feel when you rock the handle side-to-side. That needs to sit flush. Then check the 90 to make sure it's level. All it takes is tapping the end on the floor if you want to raise it up, or loosen the pressure on the bender to let it drop. Once that's set, begin the bend.


    From this angle it looks like I put about a 4-1/2" inch kick in the pipe, to the top of the pipe. Remember you need to take into consideration the O.D. of the pipe when getting your kick measurement.


    This is what you actually see. It's a good practice to measure to the top of the pipe. That way, it's easier to see when standing at the bender. Don't let the pipe slip in the bender! That could mess up your bend.


    From here you can see the kick was actually 4-5/8". This is why it's important to get a good reading when making the bend, and that usually means lowering your head to get a better look. If you need less of a kick, stand on the pipe that is resting on the floor and tap the bender shoe down on the bend or do it with your foot. If you need more, just add a little bend.

    If you were running this pipe up a column and wanted to kick the 90 around to the side of the column, chances are the radius of the 90 will get in the way. So it's important to visualize the bend before making it. 1/2" EMT and, to a lesser degree, 3/4" EMT are pretty easy to work with. If you make a mistake, the fix is usually fairly easy.

  3. #48
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    Fixing A Boo-Boo

    It happens all the time, you make a bend then check it against a level and find it's off. This is where it's good to have a creative mind, as well as an understanding of physics.


    So here's what the pipe that has been used in the demo looks like now. The 90 looks a bit off, and it is, but not as much as it looks like in the picture. Anyway, we want to get that fixed.


    It's not bad but... We want to get this right. So we have to turn the bend clockwise.


    This is where a creative mind and physics come into play. If we begin turning the bend, the bend of the offset that sits under the TS base will want to come off the floor. The TS base is raised just enough for me to fit the pipe under it and keeps that bend in the offset from lifting.


    I place the bender handle over the 90 and begin the twist, moving the handle to the left, in this picture. What you don't see is when I begin working the pipe, I have one foot on the pipe right where the kick is. This keeps the pipe on the floor completely and makes the fix much easier to do. A little rotate of the handle, check with the level, a bit more handle rotate and...


    Right on the money.

    Fixed objects work wonders when fine tuning a bend or making a fix. On the jobsite, not a day goes by that some electrician is looking for that perfect fixed object to firmly hold the pipe while making a correction. So don't be upset with yourself if you make a mistake. Practice with 1/2" EMT and you can fix just about anything.

  4. #49
    Great stuff Julie! I am an electrical contractor myself and I will tell you right now, I wish I had you around for some of my conduit jobs! I would personally rather run emt than any other form of raceway/wiring and actually find it to be fun. That clamping level really becomes handy when you get past 1" pipe and into the larger sizes. As you know you don't get those "dogs" out too easily. I've been reading this thread looking for a place to contribute but you have it covered from A to Z. Great input!

  5. #50
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    Amazing thread! Thank you.

  6. #51
    Nice info,- although I haven't worked much with metal conduit. Over here in my corner, most regular buildings use PVC conduit, hard or flex....
    Now for getting some wire into that conduit, I might add a few tricks for getting pull strings into conduit, empty or partially filled, without using dedicated wire pullers...
    Tape or fix a vacuum cleaner hose to one end of the piping, as air tight as possible, and start feeding some regular but strong string into the other end, For long runs, fix a little rag or something to the loose end... for larger conduits, I've even used a partially inflated latex glove, for lack of something more suitable....
    I've even even used this for feeding pull strings into partially filled 2'' conduits over 500' long, with only a medium shop vac at hand... it will take some time for long runs, but it works....
    The larger the diameter or longer the run, more vacuum needed......
    For shorter runs, using an air nozzle into the feeding end also works....... ( This is actually the way to do it with very ong runs, several 1000s of feet, but then you need LOTS of air..)
    Last edited by Halgeir Wold; 06-26-2015 at 5:40 PM.

  7. #52
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    Believe it or not, a standard sandwich bag works wonders as a head for getting pull string through pipe with a vacuum. On the jobsite, it's a common item, considering most workers bring their lunch to work with them. Baggies work better than a foam mouse in smaller pipe, you just have to make sure you don't stuff it in the pipe.

    If you have a big pull, you start by vacuuming in a smaller line, like jet-line, and use that to pull in larger diameter line. For the biggest pulls, we've had to go from jet-line to 1/4" poly line to as much as 1" rope to get the right size pull line in the conduit. By then, you've moved to using a tugger to pull the wire in.
    “Travel is fatal to prejudice, bigotry, and narrow-mindedness..." - Mark Twain

    Diapers and Politicians need to be changed often... Usually for the same reason.

  8. #53
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    I don't know why I didn't notice this but was doing conduit bending for the first time in the past few weeks wiring my shop. It's all done now ready for inspection by City on Monday. I figured out most of after the first try at bending went bad but good tutorial here for sure for future use.

  9. #54
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    Quote Originally Posted by mreza Salav View Post
    I don't know why I didn't notice this but was doing conduit bending for the first time in the past few weeks wiring my shop. It's all done now ready for inspection by City on Monday. I figured out most of after the first try at bending went bad but good tutorial here for sure for future use.
    Pics!!!!

  10. #55
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    It is still a mess as I have to setup my DC ducting and probably this is not the proper thread to post it. I will hopefully start a new thread for the new shop (in the new house!)

  11. #56
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    Julie: You listed a warning about not creating and offset that is impossible to build. What is the closest distance between Mark 1 and Mark 2 (to use your nomenclature from the tutorial above) that you can use?

    For example, I need to bend a 7/8" offset in 3/4 conduit. Using 30 degree bends would put the distance between the marks at 1 3/4". I don't think that would work. At 10 degrees, the marks are just over 5" apart. Will that work? How about 22.5 degrees and 2 5/16" apart?

  12. #57
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    Anthony, the bend you are talking about is outside the parameters of those equations. This is where trial and error come into play. Don't be afraid to experiment.

    This is a time when bending from the floor with equations kind of loses its value. Go to post #8. Put the bender head in the air and, keeping pressure on the pipe as close to the bend as possible, make a small bend. Then flip it 1800. Using the eyeball level in your head (we all have them), make the same bend.

    It's pressure and feel. If it doesn't work out, no problem. Take the bend out, add more bend, take the twist out or whatever it takes (see post #32). With any size pipe up to around 1", you can pretty much fix any muck-ups you create. It's really only when you get to something like 3 & 4" GRC that you begin to throw away bad bends because it's cheaper than trying to fix it.

    The only time you should throw away a bad bend is when it is offensive to your eye, when it is kinked, or when your friends want to come over to have a laugh.
    “Travel is fatal to prejudice, bigotry, and narrow-mindedness..." - Mark Twain

    Diapers and Politicians need to be changed often... Usually for the same reason.

  13. #58
    Julie

    I'm late coming to your great thread and tutorial. Way back when I was in high school (more than 60 years ago) I was a gopher for a company that installed pyrometers in plants all over southern Ohio. Back then the bender was called a Hickey--I assume that was the mfr's or inventor's name. We also used sand to keep the conduit from crimping. Are you familiar with that?
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  14. #59
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    Quote Originally Posted by Mike Null View Post
    Julie

    I'm late coming to your great thread and tutorial. Way back when I was in high school (more than 60 years ago) I was a gopher for a company that installed pyrometers in plants all over southern Ohio. Back then the bender was called a Hickey--I assume that was the mfr's or inventor's name. We also used sand to keep the conduit from crimping. Are you familiar with that?
    Mike,

    A Hickey is a different from a standard bender in that you take "bites" to make segmented bends. It looks like this:

    It's not designed for use in EMT because it's too easy to kink the pipe. You can do it but it takes finesse. Most often, I have used it on GRC (rigid) pipes coming up out of a poured concrete slab to get them plumb. Sometimes it is used as a "convincer" to nudge a pipe into place. Even on the biggest jobs, there might be only one of these on site. I saw them a lot more in my early years, though.
    “Travel is fatal to prejudice, bigotry, and narrow-mindedness..." - Mark Twain

    Diapers and Politicians need to be changed often... Usually for the same reason.

  15. #60
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    The sample workshop thread that was supposed to accompany this thread got lost. I drew up some CAD plans and showed how one might change half of a 2 car garage into workshop. Anyone wanting to view that thread: http://www.sawmillcreek.org/showthre...orkshop-Layout
    “Travel is fatal to prejudice, bigotry, and narrow-mindedness..." - Mark Twain

    Diapers and Politicians need to be changed often... Usually for the same reason.

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