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Taping the collective knowledge base.

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  • Taping the collective knowledge base.

    Hello HSM braintrust,
    I need to have three parts like the one shown in red made. I am worried that the material will not be able to handle the side tab bends. Does the material chosen have what it takes to accept such a bend without cracking? A bit of a radius at the bend would be acceptable. What do you think?
    Thanks for any input you may have.
    Please look at post 14. Anyone interested in making these?
    Last edited by Greg Parent; 06-16-2011, 02:02 PM.

  • #2
    With only three pieces obviously a die set is out of the question. So looking at the drawing I'm assuming you're starting with flat stock cutting/trimming it to size, then drilling or punching the holes, rolling the diameter then bending the tabs.

    The rolling process will induce a considerable amount of stress in the material and when you go to bend the tabs it will probably crack.

    If you can start with tubing of the correct diameter you may have a little more success.

    Is this for you or a customer? In either case I'd first try to find out if a different material can be used.

    My $0.02
    Last edited by Dr Stan; 06-06-2011, 09:50 PM.


    • #3
      +1 Dr Stan
      It is most properbly going to crack.
      Alu is not that happy when it is bent.
      I always have a problem when bending Alu thicker than 0.03
      The inside edge would hold fine but since you are trying to stretch the outside edge the material just tears apart and cracks.
      Stainless would be a better bet if you want to go non ferrous.
      Not sure if heating it will help.

      If you are using violence and it does not work, You are not using enough or it is upside down.
      You can always just EDM it...


      • #4
        It won't look pretty when you're done but, heating with mapp gas etc will do the trick nicely.

        Last weekend I had a flat of the same material 1/4" x 1-1/4" by 5", heated it evenly and bent it into an irregular c-shape to serve as a bracket/mount. Came out just fine...
        Last edited by Ray C; 06-06-2011, 05:10 PM.


        • #5
          5052 might be a better choice. It can take to bending better than 6061 t6. It's common and it's cheap. And overlooked.


          • #6

            The 6061 will crack for sure if you try to bend it like that. The T6 designation is the temper. For sharp bends (or small radius bends) you want something in condition 0 which means fully annealed. The 5052 as mentioned above would be a better choice.


            • #7
              Originally posted by Toolguy
              The 6061 will crack for sure if you try to bend it like that. The T6 designation is the temper. For sharp bends (or small radius bends) you want something in condition 0 which means fully annealed. The 5052 as mentioned above would be a better choice.
              0 temper 5052 would be hard to find. In that thin of a gauge you could wrap it around your hand like tin foil. Very hard to handle without mangling it.

              But it is available in a work hardened state that can take a fairly sharp bend, without cracking, and still retain enough stiffness to make boats out of.


              • #8
                I would anneal the aluminum first and if needed re-anneal mid process. My method is to use an acetylene flame to cover the metal with a black carbon coating. Then with a neutral flame burn off the black. Get the metal only hot enough to remove the black. If you pause with the torch you might end up with a puddle. This is using an oxy-acetylene set up.

                If the parts need to be quite nice I would use a set of secquential wooden dies and an arbor press or vise to produce the bends.

                The last step would be to drill any holes to ensure they are close to round.


                • #9
                  Everything will be much happier if you can use an inside bend radius, instead of the sharp bend shown.

                  I've gotten lots and lots of parts bent pretty much like that, though, minimal inside radius. Be sure NOT to bend along the "grain" of the aluminum, that results from rolling.

                  If I read that right, the parts are only 0.062 thick, it is the TABS on the OTHER part that are 0.125"

                  Keep eye on ball.
                  Hashim Khan


                  • #10
                    I agree that tempered 6061 T6 is a bad choice for forming these parts. It isn't very ductile. Why do you want to use 6061 T6? To get these parts out of 6061 T6, the best way is probably to start from 6061 T0 and harden/temper after bending.


                    • #11
                      Thanks for all the input.

                      I will try to use a different alloy and see if that can handle the bending. I will also try annealing it before and during the forming of the bends.

                      If aluminum can't take the bending I will try steel.

                      Thanks again.



                      • #12
                        You should consider drilling or punching the holes after bending for two reasons. First, because the holes are close to the bend the material will want to bend in line with the holes instead of where you want it to bend. Second, predicting final hole position if you put the holes in first will be tricky.

                        Also, consider making the angled cuts after bending. This will leave more material to grip while bending.

                        And I agree, T6 temper isn't going to bend very well.


                        • #13
                          Aluminum tends to bend better in one direction. It cracks much easier if you bend parallel to the rolling lines on the metal surface. Make all your bends 90 degrees to the stress lines in the metal. The metal surface will usually show signed of being rolled in one direction.


                          • #14
                            Update - anyone interested in making these parts?

                            Here are a few pictures to clear up the poor drawing I first produced. At this time I need three parts, 0.0625" aluminum or steel if the aluminum cracking is too problematic. Anyone interested in making these three parts? It may turn into more if the protoype is successful. The holes, the 30 and 60 degree angled cuts can be ignored. The radius on the side tabs will change their positions so I will take care of them myself.
                            Thanks for looking.

                            Top of tubeclamps...

                            Angled view...

                            Side tab details....holes and angled cuts can be ignored. The radius changes their positions.


                            • #15
                              What's it for? Rocket fins?