Pipe/Tube bending

Discussion in 'The Garage' started by DiabloADV, Oct 9, 2012.

  1. DiabloADV

    DiabloADV Semi-Occasional

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    So, I'm going to take on the challenge of making a custom subframe for my '70 airhead. I've got the welding part down reasonably well...been practicing and getting critique from a neighbor that knows about such stuff.

    Next up is figuring out how I'm going to bend the pipe stock. I know that a proper shop has expensive bending machines, with the right mandrels and so forth. But what does the cheap home hacker garage have?

    What's the pennytech way of getting some basic bends into these pipes? For example, a 180* bend for the back end of the subframe...

    Home built rig? Cheap Harborfreight options...?
    #1
  2. sailah

    sailah Lampin' it

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    It might be cheaper to just buy the mandrel bends from Columbia River or similar. You'll get perfect bends and you can cut to make the right angles. Downside is that you pay a premium for the bends and you probably end up overbuying since you don't want to run out right in the middle of the project.

    I recognized that I would have a real use for the bender so I bought a JD2 bender and converted it to full hydro. It makes perfect bends, and with some practice and the degree wheel, I can make repeatable bends accurate to about a half a degree. To get what I have minus the hydro is close to $750 and that's only one die.

    If you are in an area with offroaders, you might just go ahead and buy a bender with the dies you want and then sell it. You won't lose much if anything.

    I've seen plenty of people lured in by the HF siren song and their pipe kinker, it's an exercise in frustration. Bending thin wall tubing requires the walls of the tubing to be supported throughout the bend which is why the dies are so expensive.

    You can frig around with bending around a form with heat etc, but if you can spare $500-1000 for the time you will be working on your project, I'd look on pirate4x4 or clist and buy the bender then sell it when you are done.

    If you are anywhere near Pittsburgh, you can bend to your hearts delight on my bender:D
    #2
  3. DiabloADV

    DiabloADV Semi-Occasional

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    #3
  4. KeithinSC

    KeithinSC Long timer

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    I've got that same unit. Painted a different color, got it from Woodward Fab. Works nice on small OD. I made a few pannier racks with it using 3/8" and 1/2". Gotta have it clamped in something SECURELY mounted to the floor. You really have to tug on it. Did a few practice bends on some larger stuff. I cheated and heated up the tubing with my torch to make it more bendy:lol3

    I've never used a compound unit like the RBD-10, but for 1" and larger I would think it is needed.

    http://www.woodwardfab.com/woodward_fab_pipe_and_tube_bend 5.htm
    dies are extra$$$
    #4
  5. Toysrme

    Toysrme Been here awhile

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    everything this guy said is on the money

    sand bending sucks & IMO if you can afford a project, you can afford some mandrels!
    #5
  6. Smopho

    Smopho Been here awhile

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    Fill the tube with builders sand when you bend it to keep it from collapsing. Tack weld a metal slug from an electrical junction box punchout over the tube end to hold the sand in until you're done bending.
    #6
  7. victor441

    victor441 Long timer

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    Sand bending with heat from a torch can work OK if you can't justify the $$$ for a proper bender for hobby work ( I can't), I made the rack below with it on my first try....next time I'll weld a nut on one end of the tube and use a bolt to compress the sand after each bend, from what I've read this is necessary as the steel stretches on each...my first bend was best and the rest had some minor flattening. One trick I learned from the web is to make a template from wire (I used some from a coathanger) so the bend angles are the same. LOts of good info on the web and there is an interesting thread here at http://advrider.com/forums/showthread.php?t=697787
    And if you try it the sand MUST be baked first, if it is damp a violent steam explosion is possible. The accuracy will not be equal to what a quality bender can produce but is good enough for what I do...

    [​IMG]
    #7
  8. zeRax

    zeRax waaargh

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    i bend so much freakin tube it is redonkulus.


    bend up what you want it to be out of a sturdy bit of wire, ask a hydraulics shop what the thinnest wall tubing of x size they are happy to bend. take it in your material and a box of beer and get their tubey to bend it.


    no worries if you lived here :)


    or buy a cheap as multi die rotary hand bender piece of junk and just use that
    #8
  9. TUCKERS

    TUCKERS the famous james

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    What he said.

    For a one off or two project I'd just pay someone else to bend it...and I was a pipe fitter for 6 years!
    #9
  10. rd1900

    rd1900 Been here awhile

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    One tip if you are going to use a manual bender - as someone else said, it takes some force and needs to be mounted somewhere sturdy. With some 2" square tube, you can fab a bender stand that fits into a receiver hitch on a truck. This is plenty sturdy, and a lot easier and less permanent than bolting it into a concrete floor.
    #10
  11. DiabloADV

    DiabloADV Semi-Occasional

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    Excellent idea!
    #11
  12. Toyanvil

    Toyanvil Adventurer

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    I use a HF with dies a friend gave me. You can find dies on ebay and a HF bender for $50.00.
    I use grease each bend and pull the handle slow and steady.
    [​IMG]
    [​IMG]
    [​IMG]
    And just for fun :rofl
    [​IMG]
    [​IMG]
    #12
  13. bomber60015

    bomber60015 Anatomically Correct

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    For bending small OD tubing (under 1/2), I've used pullies as dies . . . . . lay the tube below the jaws of your vise, place the pulley on top of the tube, close the vise onto the pulley, and bend away . . . .

    Granted, the radius is limited to teh OD of the pully, and finding a pully that is grooved to accept the tubing size you want to bend might not be a one-trip-to-the-hardware-store deal, but, for very occasional work, it suits . . . . .
    #13
  14. DiabloADV

    DiabloADV Semi-Occasional

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    Wow! Nice looking work.
    #14
  15. DiabloADV

    DiabloADV Semi-Occasional

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    I see dies for sale, but they're for the JD2 benders. Will they work on other brands of benchtop benders (like Northern Tool or HF?).
    #15
  16. DaBit

    DaBit Been here awhile

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    I have only used elcheapo manual benders for the occasional bending I did. Sand helps a lot with tight radii, but avoiding tight bends is even better. For really tight 'bends' you can always cut the pipe in 45-degree angles and weld to form a 90-degree joint. Or multiple 22,5 degree angles. Or whatever suits you.

    It is a bit of a hassle sometimes and for example 7/8" pipe takes a LOT of force on a manual bender, but it usually works fine. And since garage floor space is limited and since I am doing it only once every few years I cannot justify buying a proper bender.

    Of course I could have someone else bend it for me, but since I am usually fabbing directly on the bike this is not very practical.
    #16
  17. NealB

    NealB Adventurer

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    I've used similar benders on DOM tubing up to 1", you may need a cheater to extend the handle for stuff above 1/2". Also, it needs to be mounted to a heavy bench. I would mount this horizontal to a bench so you push down to bend. If you mount it vertical there's a good chance you'll spin the bench around the shop as you bend larger stuff.
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    Sorry if i missed it, what size tubing are thinking of using? If this is anything structural, I would think you want the DOM tubing. Pipe is for plumbing (non-structural) and it is not as strong a DOM tubing. Another difference between tubing and pipe to note is the diameters are not the same. ex. 1" tubing is not = to 1" pipe. If you buy a bender, make sure it's for the material you plan to bend.
    <o:p></o:p>
    If memory serves me right, as long as DOM tubing wall thickness is 1/6 or 1/7 the diameter of the tubing the tubing doesn't need a mandrel (or sand) as mentioned above to prevent kinking. This is only true if the dies support the whole diameter of the tubing, like the type of dies supplied with the bender you linked to. You would want to use the sand if you're bending a around a wooden form.<o:p></o:p>
    <o:p> </o:p>
    #17
  18. jules083

    jules083 Long timer

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    Hmmmm........

    Any issues with kinking, or does it seem to follow the radius good? Preheat with a torch first?

    I have a metal lathe on the way, I'm buying it off a guy at work as soon as the overtime slows down. Vice mounted dies might make for a good first lathe project.

    Anything you can teach me about how you would make the die if you had a lathe at your disposal? :ear
    #18
  19. DiabloADV

    DiabloADV Semi-Occasional

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    I ended up ordering one of these. It's sold under a lot of brands, and I found one for $190 including tax and shipping.

    I'm making subframe and bag rack parts. 1/2 and 9/16 tubing; probably only 18 gauge. Thin stuff...easy to bend, but easy to kink. I'm optimistic this will work fine.
    #19
  20. Wreckluse

    Wreckluse Will work for beer

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    Another option if you already have a HF bender. I've got some of their tubing dies and find they work well.

    http://www.unibender.com/
    #20