bending a circle

  1. bourbon Member

    Messages:
    355
    Location:
    Lichfield UK
    Hi All. I have been asked to make a shop display. I Have designed It ( in my head) now I need to build it! I have to bend a piece of 7mmx7mm mild steel bar into a half circle. I'm waiting on the diameter at the moment. I don't have a ring bender, What would the collective do?
     
  2. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,371
    Location:
    Skelton in Cleveland U.K.
    Draw the semi-circle on the bench/floore, clamp a couple of bolts tight into the rise with a gap wide enough for the bar and just bend away by hand to match your "template" only take a few minutes.
     
    Parm likes this.
  3. fixerupper

    fixerupper Member

    Messages:
    1,478
    Location:
    Crete Greece
    If it's small upto 300 mm diameter I would use bending forks in a vice and a lenght of tube that slides on to give the leverage ...any bigger I would cut the shape out of some 18mm ply for a former to bend it round ,and use loads of clamps and try to avoid hitting it ....yeah and what he said ..
     
  4. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,371
    Location:
    Skelton in Cleveland U.K.
    7mmx7mm you wouldn't need extra leverage, Best to have the bar longer than needed and cut to length when finished.
     
    stuvy, Parm, BarrieJ and 2 others like this.
  5. bourbon Member

    Messages:
    355
    Location:
    Lichfield UK
    oh yes I have a metre of B&Q's best ( don't mock, I was in a hurry, LOL) I'm still waiting on the dimensions but shouldn't be more than 8'' across the radius
    I found this, Bit OTT but may be fun to do
     
    eLuSiVeMiTe likes this.
  6. jordan1 Member

    Messages:
    1,838
    Location:
    Yorkshire England
    16" in diameter, I thought you were talking feet.:whistle:
     
    Morrisman likes this.
  7. Hitch

    Hitch Moderator Staff Member

    Messages:
    11,920
    Somerset
    If you dont have a roller...
    8" radius, so quite big then.... cut yourself a piece of ply/mdf/gash wood about 6/7" radius to allow for some spring back, fix it to another piece, screw a side stop on the side of the bottom piece, and bend an overlength bit of bar around it tightly. Bend a bit further along than you need, check size and adjust if need be, then cut the excess off.

    The amount of spring will depend on how tight you pull it round, and what sort of bar it is.
    Just remeber, its always easier to get a bend out than it is to put it in if you over bend it.
     
  8. bourbon Member

    Messages:
    355
    Location:
    Lichfield UK
    Just been told the diameter is 7'' or thereabouts. Not too critical but it needs to be a smooth curve to look good
     
  9. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,371
    Location:
    Skelton in Cleveland U.K.
    I still believe a good job could be made quickly doing it by hand as described above, a steady pull at small increments will make a good smooth curve.
     
  10. Paul.

    Paul. Moderator Staff Member

    Messages:
    6,039
    Location:
    Northampton. UK
    Agreed, I do lots of curved stuff in stainless like this, I have a bar with a couple of round bosses about 2" dia welded to it, and just pulled it round a bit at a time checking it against a curve marked out on the bench, off cut of sheet, or even cardboard.
    Over roll it a bit then pull it out to size,

    These bucket stands were made using this method
    DSCF0038.JPG
     
    bigegg, jimbo84 and gordon stephenson like this.
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