Announcement

Collapse
No announcement yet.

How about a little metal surgery...

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

  • #31
    Not bad looks good from my views.
    BB402D
    TB300D
    DIMENSION652
    MM250X
    MAXSTAR140
    S-32 FEEDER W/1260 IRONMATE FC/GUN
    HT/PWR-MAX1250 PLASMA

    Comment


    • #32
      Thank you.

      Comment


      • #33
        Originally posted by Portable Welder View Post
        Eric Carroll, The answer is yes.

        Strengthening the top and bottom flange of the boom is stronger than reinforcing the sides, unless your trying to reinforce the boom to increase its capacity on a side swing.

        Its not that fish plating the sides would'nt offer any added strength because it would.

        But Lb. for Lb. you get more strength for the same amount of material used when adding it to the top and bottom.
        The reason I question this is it is alot harder to bend a flat bar on edge than it is to bend one laying flat. In rolling bending terminology it is refered to as hard way or easy way. Take a 4' piece of 1/4"x 1", you can bend it the flat way with your hands, try that on edge-no way. Please dont think Im trying to prove anyone wrong, its just that I have rolled and bent tons of steel, and made lots of fish plates for booms, trailers,LVL beams and they have all been stressed the "hard way".

        Comment


        • #34
          Daniel, what is that blue stand? Is it an electric box? Thanks
          Fab Tech

          Comment


          • #35
            Yes, It's got a long extension cord and a heavy base.

            Comment


            • #36
              Im trying to come up with a portable extension cord rack, your stands a great idea, nice height
              Fab Tech

              Comment


              • #37
                Originally posted by Eric Carroll View Post
                The reason I question this is it is alot harder to bend a flat bar on edge than it is to bend one laying flat. In rolling bending terminology it is refered to as hard way or easy way. Take a 4' piece of 1/4"x 1", you can bend it the flat way with your hands, try that on edge-no way. Please dont think Im trying to prove anyone wrong, its just that I have rolled and bent tons of steel, and made lots of fish plates for booms, trailers,LVL beams and they have all been stressed the "hard way".
                True, Eric, but think of an I-beam or an H-beam. Normally, the heaviest parts are the top and bottom flanges, with the web being half or less the thickness. An engineered structure, such as a box beam on an excavator arm, is the same. Adding additional metal, will do the most good, with the least amount of metal, if you put it closest to the maximum stress, which is normally at the top and bottom.
                Obviously, I'm just a hack-artist, you shouldn't be listening to anything I say .....

                Comment


                • #38
                  Originally posted by JSFAB View Post
                  True, Eric, but think of an I-beam or an H-beam. Normally, the heaviest parts are the top and bottom flanges, with the web being half or less the thickness. An engineered structure, such as a box beam on an excavator arm, is the same. Adding additional metal, will do the most good, with the least amount of metal, if you put it closest to the maximum stress, which is normally at the top and bottom.
                  Yes sir. Look at any load chart. Compare an S-shape to a W-shape, M-shape, or HP-shape. S-shapes come in a very distance 4th place! It is all about the flange.
                  Caution!
                  These are "my" views based only on my experiences in my little bitty world.

                  Comment


                  • #39
                    Originally posted by JSFAB View Post
                    True, Eric, but think of an I-beam or an H-beam. Normally, the heaviest parts are the top and bottom flanges, with the web being half or less the thickness. An engineered structure, such as a box beam on an excavator arm, is the same. Adding additional metal, will do the most good, with the least amount of metal, if you put it closest to the maximum stress, which is normally at the top and bottom.
                    For a specific example . . . consider a piece of 1/4 x 3/4. True, it's almost 9 times as hard to bend it the "hard way" as the "easy way". Now plate it on both sides . . . you have a piece 3/4 square. Plate it top and bottom and you have an I beam 3/4 wide and 1-1/4 tall.

                    Compared to a piece of 3/4 square, the I beam is 2.4 times as hard to bend (assuming a vertical load and vertical web).
                    Dynasty 300DX
                    MM350P
                    Hobart Handler 120
                    Smith LW7, MW1, AW1
                    Smith AR/He Mixer

                    Comment


                    • #40
                      Originally posted by JSFAB View Post
                      True, Eric, but think of an I-beam or an H-beam. Normally, the heaviest parts are the top and bottom flanges, with the web being half or less the thickness. An engineered structure, such as a box beam on an excavator arm, is the same. Adding additional metal, will do the most good, with the least amount of metal, if you put it closest to the maximum stress, which is normally at the top and bottom.
                      The way I think of it is the metal farther away from the neutral axis (center of bend) has more leverage to resist bending. Putting more material on the flange is only good up to a point. When you start crushing and wrinkling the web, the flanges quit working.

                      Dynasty200DX w/coolmate1
                      MM210
                      MM Vintage
                      Lincoln AC225
                      Victor O/A, Smith AW1A
                      Cutmaster 81
                      IR 2475N7.5FP
                      Evolution Rage3
                      Jancy USA101
                      9" South Bend
                      AEAD-200LE

                      Comment


                      • #41
                        Simple illustration:

                        Take a yardstick place it on its edge with two pencils placed perpendicular to the yardstick, one pencil at the 1-inch point, and the other pencil at the 35-inch point. Place your pointer finger on the top edge of the yardstick at the 18-inch mark then push down. Which way will it move? It may go straight down a little, but it will move to one side or the other. That is exactly how a beam will fail under load. The wider / heavier the flanges are the more resistance to side movement / failure there is.
                        Caution!
                        These are "my" views based only on my experiences in my little bitty world.

                        Comment


                        • #42
                          And that's how that boom failed or snap in half, by pulling a load of trees side ways.
                          The cylinder was actually the one that came with the loader from factory, my bad, he just had the hydrolics cranked to the max.
                          Hard to believe the he used to lifted quads trailers that weight 17000 pounds to load them on the truck when they were empty.
                          The boom was " where it broke" all 3/8 thick plates. Around 18 inches by 18 inches boxed.

                          Comment


                          • #43
                            Eric Carroll,
                            I understand why you would question this, I too used to think about it as you do.
                            I remember the first time that I had to go out to do a house beam reinforcement because the customer wanted to remove a column that was in the way of his new pool table.

                            When the contractor handed me the engineered drawing showing me to weld a pc. of 1/2"x 6" flat bar to the bottom flange of the beam and then 2pcs. of 1/2" x 2-1/2" flat bar to the bottom sides of the top flange I thought ( WOW where did they find this crack pot engineer )

                            Then another job came up and a different engineer had me do it the same way, I thought Wow the 2 engineers must of went to the same school.

                            Eric, Where your way quits working is when you start seperating the 2 flat bars and add a webb. The top flat bar starts wanting to compress while the lower flat bar wants to pull apart verses bend and thats where the difference comes into play.

                            For instance take a look at the bar joist in the big box stores.
                            The bar joist is the same as a beam it has angle Iron for the top and a bottom flange and the webb which is the part standing up on end is nothing more than a diagonal round bar in many cases.

                            You've always been told when building a header in a house that the pc. of plywood standing up on end between the 2" x ? gives it alot of extra strength that is not totally true, Its more for spacing it out.

                            Another example is the boom on cranes like a Gradall for instance, You've probably seen some of these that have round circles cut out of the sides which would be considered as the webb.

                            As some one mentioned in an earlier post the farther you move the material away from the center axis the more strength you get.

                            I hope I was able to help. Portable Welder.

                            Comment


                            • #44
                              dang, i am jealous of that job! I live for those things!! 2 months ago, i came across a cat (mitsubishi) excavator boom that was cracked and splitting just under the base of the stick cylinder. the top and bottom are 1/2 and the sides of the boom were 3/8. plating the sides only gains nominal strength simply to help the boom from twisting under extreme loads... i.e. pulling up trees. plating the top and bottom is a must, as these things lift and lower, yeah? i gotta start taking pics of these major equipment screw ups that i repair. last year, it was a tele-handler (extendable fklft like a gradall or skytrack) made by cat. the brake was never set and it rolled face first down a mountain side and landed on the boom..... that one took me about 5 months to repair
                              welder_one

                              nothing fancy, just a few hot glue guns for metal
                              www.sicfabrications.com

                              Comment


                              • #45
                                Adding metal to the sides of a box beam, will stiffen the beam, not necessarily make it stronger. More likely, it will create a new stress point, for a brand new crack to start. Think about it a little, long and hard. I started many many years ago, doing "Hopto" beams. Don't know what a Hopto is???? Dam, I'm old.
                                Obviously, I'm just a hack-artist, you shouldn't be listening to anything I say .....

                                Comment

                                Working...
                                X