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Dewalt 740 Radial arm saw

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  • Dewalt 740 Radial arm saw

    There is a used Dewalt 740 radial arm saw on sale for $65 that I'm considering buying. I know very little about radial arm saws in general and nothing about this specific saw. I do have several projects that will require milling dados in wide boards and anticipate using this saw only for this purpose.

    My questions are:

    1. Is any one familiar with this saw?

    2. What specific aspects of the saw should I examine when I look at it? I'll make sure that it maintains it's angle and height settings and seems to be in generally good condition.

    Thanks.

  • #2
    Re: Dewalt 740 Radial arm saw

    Not familiar with the DeWalt 740 but for any RAS there are a number of things to check.

    1. Check that all controls work.
    2. Check that all parts are included, especially the guard assembly. A RAS is not like a TS in that you can work w/o the guard. For a RAS you need the guard in place 99.5% of the time. There are a couple cuts or accessories that might require removing the guard, but they are few and those are special cuts which you will not run into most times.
    3. Check condition of power cord. If not soft and flexible with no signs of cracking or other damage to the outer jacket of the power cord then figure on replacing the power cord right off the bat.
    4. Check the stand and table top and make sure all the parts are there. If the table is missing well at $65 you can't say much. Just figure on picking up some MDF or ply to make a new top with.
    5. Does it come with the owners manual? You'll want this more for the alignment/setup procedure than anything else.
    6. Check the bearings on the carriage for wear, damage, or a build up of gunk and sawdust. This will affect smoothness of travel as well as accuracy of cuts.

    I'm sure I missed a couple things. CWS who is so in love with his RAS that he sleeps with it will have more no doubt. :-) I won't part with my RAS either, so I guess I shouldn't talk.
    "When we build let us think we build forever. Let it not be for present delight nor for present use alone. Let it be such work that our descendants will thank us for, and let us think, as we lay stone upon stone, that a time is to come when these stones will be held sacred because our hands have touched them, and that men will say, as they look upon the labor and wrought substance of them, "See! This our fathers did for us."
    John Ruskin (1819 - 1900)

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    • #3
      Re: Dewalt 740 Radial arm saw

      cjh,

      I'm not at all familier with that model or DeWalt RAS's in general, except to know that they were the original designer and manufacturer and that over the years they have had a generally good reputation. Near the end of production, they did produce a couple of models that were rather simplified and thus less costly to produce. But even then, I am not aware of anything that would discredit their reputation.

      I have owned an Emerson-made, Craftsman since 1974 and it is my favorite tool. So, what I would look out for when looking at a used RAS is general slop or looseness in any of the major components:

      With the arm locked in position, there should be no slop/movement in the column. That is discovered by placing your finger at the place where the column goes into it's vertical support and by trying to nudge the arm either right or left. At the column, you should be able to feel any movement that might take place. If detected, that's a worn locating pin or locking mechanism that needs to be replaced. You'll never get a consistant cut with a worn column or locking mechanism.

      Likewise, the carriage should move forward and back on the arm easily with absolutely no wobble. It should also be able to be firmly lockd into any position along the arm.

      Once locked, grab the carriage and try to move or wobble it. It should be solid with no movement.

      The carriage yoke should be able to both smoothly pivot and rotate to any position under the arm and be solidly locked into any position. If it isn't smooth, then something is corroded or worn. If it doesn't lock into any position than something is worn.

      Obviously any detection of worn parts will either need adjustment or replacement... most likely the latter.

      There's a lot of RAS models out there and finding a good one shouldn't be too much of a problem, especially if it's from a good shop. But, be aware that often these fine tools are "inherited" and may well have seen some years of idleness, poor care, and storage. Also of course are those few tools which may have been purchase by those who lacked an appreciation and therefore may have been mishandled or worse.

      Good luck and Merry Christmas,

      CWS
      Last edited by CWSmith; 12-22-2009, 09:41 PM.

      Comment


      • #4
        Re: Dewalt 740 Radial arm saw

        BobD,

        While I clearly appreciate your very respecful acknowledgement of my affection for my RAS, I would like you to know that I DO NOT SLEEP with it.

        Now that you have that clear, let me point out that the table does provide a good resting place for one's head during an afternoon snooze, as long as you swing the arm out of the way! If forgetful of that, it can cause a severe lump should one be startled by the wife's yelling for you to leave the shop!!!

        Merry Christmas Bob,

        CWS

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        • #5
          Re: Dewalt 740 Radial arm saw

          Thanks Bob and CWS,

          Thank you for your comments. I'm thinking that at $65 its pretty much a good deal if it is safe. I will be sure I look at each item you mentioned. I'm planning to examine the arbor - any thing different on a RAS from a table saw that I sould be aware of?

          -Chris

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          • #6
            Re: Dewalt 740 Radial arm saw

            Originally posted by cjh20 View Post
            any thing different on a RAS from a table saw that I sould be aware of?-Chris

            Yes, with an RAS the blade is on the top!


            Seriously though... with an RAS, you shouldn't use a conventional, positive hook angle blade without being aware of it's serious "climb" self-feed tendencies. A blade with a 5-degree, negative hook angle is often recommended.

            Basically, the problem will manefest itself on cross-cuts, as you pull the blade into the stock, it will have a tendency to grab into the stock and advance itself toward you. The idea on operating is for you to forcibly control that advance and be fully aware of that "climb" tendency.

            The thicker the stock, the more pronounce will be the "self-feed".

            That said, I have never used a negative-hook angle though. Just be careful and aware of the probability, and operate accordingly.

            Not having a table saw until only a couple of years ago, I have done a lot of ripping on my RAS since 1974, including sheet stock. You always feed from the back of the saw, against the rotation of the blade and you ALWAYS use the anti-kickback pawls.

            Ripping on an RAS is a topic much disputed by many! I've done it, been happy with it, and never suffered from it. But, I willingly attest to the fact that ripping is one place that the table saw is supreme! Crosscutting however, is the RAS's domain.

            I hope this helps,

            CWS

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            • #7
              Re: Dewalt 740 Radial arm saw

              CWS,

              Actually, I was referencing the arbor (poor writing skills) but you bring up a good point. I'm aware of the need for a negative hook blade, but should I be concerned with my dado blades? I don't remember having read anything on a dado blade on a RAS. I assume that since it is a non-through cut, the danger is neglegable with a 0 degree hook. I need to think about this.

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              • #8
                Re: Dewalt 740 Radial arm saw

                I've never used a dado blade on my RAS, preferring to make multiple passes or use the router instead. Actually I haven't done a lot of dado work.

                But, the RAS certainly will take a dado blade and all the instruction material that I've read show it's use. As far as self-feeding is concerned, I'm sure it is something that you still have to be careful of, but certainly with the smaller diameter of the blade pack and the zero hook angle, I would think you'd be just fine.

                The one thing that I am fairly certain of is that you'd be safer than on a table saw... because you will see what the blade is doing and you can better control the feed rate of the carriage on a crosscut.

                Perhaps I say that only because I watch my father remove a couple of fingers running a shaper head on a table saw, when I was only 14. I know it's different than a dado, but it's still cutting a blind swath on the underside of the stock, where you can't see it. He hit a knot or something, and with no guard in place, his hand was pulled into the cutter. Really nasty and I can still remember the sound, even though it was more than fifty years ago.

                That single incident is what drove me to the RAS. There, I can always see the blade, what it is cutting and how well it is doing.

                CWS

                Comment


                • #9
                  Re: Dewalt 740 Radial arm saw

                  i have used a freud 8" dado set up on my craftsman RAS. and even though it's older than CWS's, it powered through 4" pressure treated posts with no difficulty. the thing you have to remember is that the motor will accelerate towards the operator if too much material removal is attempted in one pass. this can be dangerous to the operator (removal of appendages) and the saw (stalling and attendant overloads). with appropriate care, a dado blade works well on a RAS. i've even seen norm use that set up on NYWorshop. for $65, i'd go for the dewalt. it's a good deal at that price, and a great deal @$50. HTH.
                  there's a solution to every problem.....you just have to be willing to find it.

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                  • #10
                    Re: Dewalt 740 Radial arm saw

                    Originally posted by CWSmith View Post
                    I've never used a dado blade on my RAS, preferring to make multiple passes or use the router instead. Actually I haven't done a lot of dado work.

                    But, the RAS certainly will take a dado blade and all the instruction material that I've read show it's use. As far as self-feeding is concerned, I'm sure it is something that you still have to be careful of, but certainly with the smaller diameter of the blade pack and the zero hook angle, I would think you'd be just fine.

                    The one thing that I am fairly certain of is that you'd be safer than on a table saw... because you will see what the blade is doing and you can better control the feed rate of the carriage on a crosscut.

                    Perhaps I say that only because I watch my father remove a couple of fingers running a shaper head on a table saw, when I was only 14. I know it's different than a dado, but it's still cutting a blind swath on the underside of the stock, where you can't see it. He hit a knot or something, and with no guard in place, his hand was pulled into the cutter. Really nasty and I can still remember the sound, even though it was more than fifty years ago.

                    That single incident is what drove me to the RAS. There, I can always see the blade, what it is cutting and how well it is doing.

                    CWS

                    Comment

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