Announcement

Collapse
No announcement yet.

Bend & shear project?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Bend & shear project?

    It has been a while since I have posted on here I have a question that I thought would be best asked here so here it goes.

    I need to shear and bend hundreds of small parts from SS coil stock I need to bend some 1/2" wide SS coil stock into a horshoe for lack of a better description the part is made from .025" thick and is 3/4" long with a bent end roughly .200" long on each end. (.200" then 90* bend .750" then another 90* bend .200" long to the end.)

    I need to buy something to shear the bulk material and some sort of brake or a homemade die to use in my hydraulic press.

    What would be the best machine for this?

    I thought about buying one of these it is way overkill but I could do some other projects with it.

    http://www.use-enco.com/CGI/INPDFF?P...MITEM=130-5610

    I am wondering if this machine would have a back stop for use with the brake that would be able to be set @ .200" and I am also wondering if you could make 2 90* bends .750" apart? Would the shear have a fence or stop to shear all the parts the same length? I am sure someone on here probably owns one of these 3 in 1 machines.

    Thanks Mike

  • #2
    i would cut the small parts with a good hand type "tin snip" and make a male / female die to use with my arbor press for making the bends. minimal investment, takes of little space.

    i don't think a double 90 bend would be possible without distorting it.

    try it by making some cardboard mock-ups of tooling and material you plan to use.

    Comment


    • #3
      Is hundreds short for A LOT...or is hundreds like maximum of 200.

      What kind of tolerances?

      I'd probably just make up a small pan brake for the purpose.

      For the shearing, probably make up a small quick shear, or use a beverly shear.

      Comment


      • #4
        Originally posted by gundog
        I need to shear and bend hundreds of small parts from SS
        coil stock I need to bend some 1/2" wide SS coil stock into a
        horseshoe for lack of a better description the part is made from
        .025" thick and is 3/4" long with a bent end roughly .200" long
        on each end. (.200" then 90* bend .750" then another 90* bend
        .200" long to the end.)

        I thought about buying one of these. It is way overkill but I could
        do some other projects with it.

        http://www.use-enco.com/CGI/INPDFF?P...MITEM=130-5610

        I am wondering if this machine would have a back stop for use
        with the brake that would be able to be set @ .200" and I am
        also wondering if you could make 2 90* bends .750" apart? Would
        the shear have a fence or stop to shear all the parts the same
        length? I am sure someone on here probably owns one of these
        3 in 1 machines.
        They do come with rudimentary backstop provisions, but I do not
        believe the proposed machine has sufficient capacity for shearing
        0.025" stainless material.

        While those 3-in-1 Combo Shear, Brake & Roll machines are rated for
        20ga mild steel in the US, the same machines are rated at 22ga in
        Canadian outlets. This leads to the question - whose gauge standard
        are these identical machines rated by in the respective markets?

        Steel Sheet (mild & SS)
        • 20ga (0.0359")
        • 22ga (0.0299")
        • 23ga (0.0269)
        • 24ga (0.0239)

        From personal experience, 22ga cold rolled sheet that verniers at
        0.0290" can be sheared grudgingly by a 30" Combo machine. Lighter
        mild steel material shears more satisfactorily - the emphasis here
        being on mild steel.

        The shear strength of stainless is significantly greater than for mild
        steel and within stainless grades, shear strength of ferritic (300 series)
        grades is greater than that of austenitic (400 series) grades.

        For a machine of a given gauge capacity in mild steel, this capacity
        must be downgraded when working with material having higher shear
        strength.

        From pg 3 of Stainless Steel Fabrication Designer Handbook, published
        by the Speciality Steel industry of North America
        Typical relative derated capacities are as follows
        • Low Carbon (mild) steel 0.4" (10mm) thick material
        • Ferritic Stainless Steel (T430) 0.3" (7-8mm) thick material
        • Austenitic Stainless Steel (T304) 0.2" (5-6mm) thick material.

        From the above, it appears that a given shear can only cut 50%
        of the thickness of 304 SS that it is rated to cut for mild steel.
        Since my combo machine strains to shear 0.0290" mild steel, I
        wouldn't expect it to be happy shearing beyond 0.0145" 304 SS.
        Turning this round, to cut 0.025" 304 SS, I would seek out a shear
        rated for cutting 0.0500+ mild steel - 18 ga is 0.0478" so I'd prefer
        to hold out for 16 ga (0.0598) capacity.

        Shearing Stainless has some other considerations, too. The handbook
        above has additional recommendations for knife clearance differences
        and additional aspects.

        If there is time, fabricating your own shear might be worth considering.
        If not, some specialty tool suppliers like Otto Frei have heavy duty rolls
        and shears for jewelry work that might be useful.

        .
        Last edited by EddyCurr; 03-12-2010, 01:55 PM.

        Comment


        • #5
          A die shoe with tooling to form the part and shear the length,
          all mounted in a bench top OBI (open back inclinable) punch press
          would make short work of the job.

          .

          Comment


          • #6
            This sounds like the kind of job I would get stuck doing for much less money than I should have charged. If you have to tool up for this I suggest looking for a 36" pexto foot squaring shear. You can usually pick up a 16ga shear pretty cheap in the shorter models. If you don't have a brake it would be pretty easy to make a small simple job-specific one for the .200" return.

            Remember, the radius of the bend will add to the dimensions of the part so don't cut a lot of peices until you get the exact measurement worked out.

            Bob

            Comment


            • #7
              This is not a close tolerance part +- .060" the coil stock is 1/2" wide already and I just need to shear it to length and bend. I have made a proto type using tin snips and bending with pliers but I need to make hundreds and make them quickly to make money making these parts cycle time is important.

              The job is for my own small marine products business for a new product I am making. The parts ends up being a wear strip to protect some plastic. There is a threaded stud that screws into a square nut machined into the part this wear strip fits over the stud and when it is tightened it protects the plastic from maring. The parts machined to slide together using a dovetail. There are 2 slots 1/8" wide 3/4" apart the part is actually bent over 90* so that a little tension is created when the part is put in place. I will try and get up a picture.

              Mike
              Last edited by gundog; 03-12-2010, 08:08 PM.

              Comment


              • #8
                Here are some pictures.

                This is a side view of the part the way it will be used.



                This is the part it fits into.





                The part in place.

                Last edited by gundog; 03-12-2010, 09:04 PM.

                Comment


                • #9
                  The nut in place the part fits over that.



                  The whole thing assembled.



                  You can see I have over bent the ends to give it some grip so when the parts are slide apart it does not fall out. I am just looking for the best way to cut and form these parts in a home shop. I don't mind buying a shear and brake but my shop is full and I am having trouble with adding things that take floor space a bench top shear brake would be better.

                  Thanks Mike

                  Comment


                  • #10
                    Punching

                    Hydraulic press is a PITA and probably over-kill as regards power/force but slow and boring - ie will take a lot of time.

                    Why not use or modify a larger (3T>5Tonne) arbor press which should do the job, is quick and with luck, cheap. It takes up little shop space. It will also more accurately locate the punch to the die and may not need a bolster (a hydraulic press might though).

                    Comment


                    • #11
                      Self contained crop and form tool, fed from strip on edge with a simple toggle action and drop through to tray underneath. Hydraulics or electrics?? why bother it isn't complicated enough to thow technowlegeee at.

                      Regards Ian.
                      You might not like what I say,but that doesn't mean I'm wrong.

                      Comment


                      • #12
                        Originally posted by Circlip
                        Self contained crop and form tool, fed from strip on edge with a simple toggle action and drop through to tray underneath. Hydraulics or electrics?? why bother it isn't complicated enough to thow technowlegeee at.

                        Regards Ian.
                        I like that idea but I have no idea how to make such a machine.

                        The above idea would be ideal but I do not know how to build something like that. My idea was to set up some type shear with a stop so I could shear them to length and then make a die for my home made hydraulic press to line up multiple parts so when I press I bend a dozen or so at a time.

                        If someone can show me how to make a machine or make one to sell me that would do this all in one operation I would be interested send me a PM or email me @ [email protected]

                        I also considered buying a 3 in 1 machine if it would work I understand the bender I showed in the link is rated at 20 gauge mild steel but that is for a full 30" length I am sure it would shear .020"-.030" SS 1/2" wide. I have a large welding table I could keep the 3 in 1 bender on. If the 3 in 1 bender won't work that good for what I am doing I would like to know that before spending the $$.

                        Mike
                        Last edited by gundog; 03-13-2010, 11:24 AM.

                        Comment


                        • #13
                          How many do you need to make? You never really answered that question. Hundreds is sorta non-descript.

                          What is your target cost per part? If you are looking at buying a machine, it seems that your target cost could be pretty high.

                          Need more information.

                          Comment


                          • #14
                            Originally posted by gundog
                            ... but I do not know how to build something like that. My idea was to
                            set up some type shear with a stop so I could shear them to length
                            and then make a die for my home made hydraulic press to line up
                            multiple parts so when I press I bend a dozen or so at a time.

                            I also considered buying a 3 in 1 machine if it would work ... If the
                            3 in 1 bender won't work that good for what I am doing I would like
                            to know that before spending the $$.
                            While a HSM-built shear/forming tool may one option, it sounds as
                            though it may not be feasible at this time.

                            My thoughts on the inadequacy of the Combo machine and some
                            supporting material were posted earlier. As an alternative, heavier
                            capacity specialty tools from outlets like Otto Frei were suggested.

                            A less expensive manual shear option that might work for short runs
                            may be a Bench Top Shear. These come with various blade lengths
                            and the lightest duty (5") is rated for 0.09375 (3/32) mild steel plate
                            - that provides well over a factor of three relative to the 0.025" SS
                            intended for cutting. Setting up a back stop, along with a strip feed
                            guide should be easy to do with simple materials and tools.

                            Many outlets carry simliar versions of Bench Top Shears. This one
                            is from pg 623 of Enco's catalog

                            .

                            Comment


                            • #15
                              Originally posted by snowman
                              How many do you need to make? You never really answered that question. Hundreds is sorta non-descript.

                              What is your target cost per part? If you are looking at buying a machine, it seems that your target cost could be pretty high.

                              Need more information.

                              It is a new product for me and customer demand will decide the number needed to be made I hope millions but I will have to see. I have 225' of coil stock so that comes out to about 2160 parts. I plan to cut 200 to start with and see where it goes. I have been looking at those hand shears and I think I will start with one of those and set up some sort of stop. Thanks for all the input. Cost per part should be pennies spending money for the machinery to make them is expected time is money so it does not take long to pay for machinery if you can cut the labor time down.

                              Mike
                              Last edited by gundog; 03-13-2010, 04:44 PM.

                              Comment

                              Working...
                              X