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Arbor press size/tonnage/leverage??

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  • Arbor press size/tonnage/leverage??

    I have two arbor presses, both obtained used. As it happens, neither is a Dake, or reputable US brand. One is a Taiwan Jet "#1", the other an ancient Japanese "#2". The #2 is about twice as big as the #1

    OK...

    I am fine with the ratcheting ones, which these are NOT..... I see the deal there.

    But, on the regular non-ratcheting, how does the actual variance of leverage correlate with the tonnage?

    You would expect that the leverage would be in relatively similar proportion with the tonnage, since after all, a person has to pull on the lever to get the "tonnage".

    The #1 has a ratio of 16:1. The #2 has a ratio of 17.5 :1

    Dake quotes a 1 ton with 25:1, a 1 1/2 ton with 32:1, and a 3 ton with 36:1

    NONE of these is in a ratio corresponding to the tonnage, not even the Dake. Not even teh compound leverage Dake, and not EVEN the ratchet leverage Dake.

    I assume the tonnage rating has more to do with the amount of pipe you can add to the lever and still probably not break the frame, than it does with the actual as-supplied leverage.

    In teh case of teh 15 ton ratchet Dake, the ratio is 150:1. So for 15 tons, your pull is a frictionless 200lb. For the similar 3 ton, it is 125lb. OK, for that money you better get something, although your hand is gonna be sore at max pressure.

    For the plain Dake 1 ton, it is 80 lb. For the 1 1/2, it is 93lb. For the 3 ton it is 166 lb. Some serious weight needed on the lever to get the higher ratings, your hand isn't going to deal with that nicely.

    For my "1 ton" (unjustified rating assumption) it would be 125 lb, and for the "2 ton" it would be 228 lb, which means I would have to put some pipe on it, I am not that fat, and I like my hands without dents.

    Naturally, the real pressure is higher. The friction etc will eat up part of the handle pull, I would assume.

    Is there any rationality to the tonnage rating vs pull on ANY arbor presses?

    If not, as it seems, what does the rating really mean, frame breakage point?
    1601

    Keep eye on ball.
    Hashim Khan

  • #2
    I can't answer your questions. I have 2 Dakes, an old 3 ton ratcheting arbor and an old 70 ton hydraulic H which I seldom use. The frame of the 3 ton is massive, I seriously doubt the rating is based on its failure. I've never added a cheater pipe to it, I'm sure the lever would bend long before the frame even noticed it. When 200lbs on the end of the lever won't do it it's off to the H frame or add some heat.

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    • #3
      I dunno,it could be the case that the ratings are BS on some units,or they could be the point at which the frame deflects beyond aceptable limits.
      I just need one more tool,just one!

      Comment


      • #4
        Well, I figured it was based on "non-failure", as in at that pressure it won't fail the frame, you are at the safety margin point.

        I agree the lever might bend, although some of those ratchet units look pretty stout.

        Just wondered how the numbers were arrived at. Surely would be a gorilla pulling to get them with no cheater.
        1601

        Keep eye on ball.
        Hashim Khan

        Comment


        • #5
          I have the 2 ton press imported by Enco. I have no idea what the gear ratio is. For most things it's fine, but yesterday I was trying to press fit a couple of things together and it just wouldn't do the job. I guess I should have cut off another thousandth! I eventually did get the parts together but I had to actually hang off the lever to do it. Lucky for me, I've been eating a lot of pizza lately
          Stuart de Haro

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          • #6
            Just how large an arbor press should be to do some broaching? Assume the largest broach will be 1/4" in steel. I've been debating purchase of an arbor press weighing the pros and cons of 2 or 3 tons and the weight to move them around. Also if it is a worthwhile investment to get a ratcheting press. The other jobs I'd have for the press would be to fit bearings or press parts together. So far except for broaching I've been making do with a large bench vise.

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            • #7
              Originally posted by **** Plasencia
              Just how large an arbor press should be to do some broaching? Assume the largest broach will be 1/4" in steel. I've been debating purchase of an arbor press weighing the pros and cons of 2 or 3 tons and the weight to move them around. Also if it is a worthwhile investment to get a ratcheting press. The other jobs I'd have for the press would be to fit bearings or press parts together. So far except for broaching I've been making do with a large bench vise.
              I would go for the 3ton,I have a 5ton Greenard that still requires about 30-40 lbs on the handle to push a 1/4" broach.

              If you can swing a ratchet type then by all means get it.If not a cheap 3/4" drive ratchet and a 3/4" drive socket welded to the pinion of a plain press is a good substitute.
              I just need one more tool,just one!

              Comment


              • #8
                Weirdscience.
                Many thanks for the ratchet wrench suggestion. I wish I were that smart all the time! I figured a 3 ton press would be big enough to handle a job like that but the weight of the thing really puts me off. I may need to move it every so often in my limited space. I got a lift table so maybe that will be OK. Thanks again.

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                • #9
                  Press size for broaching

                  The size to look at when getting a press for broaching would be how high the ram is from the table. Many of the Enco arbor presses would only let you broach a peice 2" or 3" long, if that, when you include the length of the broach itself. At work I use a ratcheting Drake with 24" between the ram and table. On occasion I can do up to 1/2" key way in softer metals like machine steel.

                  mark61

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                  • #10
                    Mark61 tells it true....

                    Most presses have pretty small "daylight".... but the Dake seem to have, by comparison, huge daylight.... just shy of 12" on a 1 1/2 ton ratchet.

                    That's plenty, my "#2" has about 7", which is pretty tough on most of the broaches.... but then it is a single-leverage

                    Admittedly, the other single-leverage Dake have comparable daylight, 4 1/4 or 7 3/4 inches, but the 3 ton single has 11 1/2" daylight, 10 3/4" to the plate.
                    1601

                    Keep eye on ball.
                    Hashim Khan

                    Comment


                    • #11
                      You need at least 14" of daylight for the standard Dumont keyway broach to work.They will only cut 2" of .....maybe 2-1/2" of keyway ,if you hold your mount right,in soft steel.The broaches themselves from memory are 11-1/2" long with about 1" of that slipped into the bore at the start and the part length 14" is cozy.
                      I just need one more tool,just one!

                      Comment


                      • #12
                        If you need 14", then there isn't a hand single leverage arbor press made that will press one thru.

                        I don't think any of the ratchet Dake under 5 tons have that much except the 1 1/2-B. None of the single leverage ones are even close.

                        You have to go to the "compount leverage" units.

                        You sure about that figure?
                        1601

                        Keep eye on ball.
                        Hashim Khan

                        Comment


                        • #13
                          I'll check today,but I am fairly certain he will need 14" minimum of 13"for a Dumont C broach to work.
                          I'll also check some of the import presses,I think they make a 3ton ratchet that will clear 14".
                          I just need one more tool,just one!

                          Comment


                          • #14
                            A 'D' series broach is 14", a 'C' series is 12". Maximum keyway for the 'C' series is 3/8".
                            Jim H.

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                            • #15
                              How about the broaches for 1/8 , 3/16, and possibly 1/4"?

                              Seems like they might be shorter, I recall some that couldn't have been much if any longer than about 6". But they were for small keyways.

                              I suppose a person could make a very short broach that needed a couple extra shims and the associated extra passes, in order to use a short-clearance press. Still would be less aggravation than "carriage-shaping" a keyway, which I have done several times.
                              1601

                              Keep eye on ball.
                              Hashim Khan

                              Comment

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