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Thread: Dewalt 7770 Radial Arm Saw

  1. #1

    Dewalt 7770 Radial Arm Saw

    I have the chance to purchase a Dewalt 7770-10, 10 inch radial arm saw. Does anyone know if this was a good saw or if it was one to avoid. I searched OWWM and someone had said that Mr Sawduster recommended this saw but I don't know. Thanks

  2. #2
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    Looks like a Powershop model. Think the one Mr Sawdust liked was a GWI. I've got both (by dumb luck) The 7770 appears to be a good saw but the GWI is a monster, I love it.

  3. #3
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    In addition to the wonderful information you get here, there's a forum (Google: Delphi DeWalt Radial Arm Saw, for the link) specifically for the older DeWalt RAS's.

    Mine's a 1956 MBF, and ... it's love

  4. #4
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    Hi Neal

    The DeWalt 7770 is generally inferior to the older models, with one exception. It's a relatively late model saw and suffered from lots of downgrades, such as plastic and sheet metal parts where cast iron had previously been. The exception is the motor, which is much more powerful than the older 110v saws. If the 7770 is cheap enough, it's worth buying in order to get the excellent motor. That's what I did. That motor will fit onto some of the older, better saws. Not all of them, though. If you're interested, I can help you sort through what will work.

  5. #5
    Quote Originally Posted by david brum View Post
    Hi Neal

    The DeWalt 7770 is generally inferior to the older models, with one exception. It's a relatively late model saw and suffered from lots of downgrades, such as plastic and sheet metal parts where cast iron had previously been. The exception is the motor, which is much more powerful than the older 110v saws. If the 7770 is cheap enough, it's worth buying in order to get the excellent motor. That's what I did. That motor will fit onto some of the older, better saws. Not all of them, though. If you're interested, I can help you sort through what will work.
    David, thanks for the info. The owner wants $75, he bought the saw new in '87 and claims he hasn't used the saw more than a dozen times. It has sat in his garage. What other saws will this motor fit?
    I've also checked out the Delphi forum, lots of good info there.
    Last edited by Neal Daughtry; 07-10-2011 at 9:55 PM.

  6. #6
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    Hi Neal

    His price seems OK, especially if everything works and is in good shape and has the anti kickback arm. You could always use it as a stop gap until you find something better down the road. Heck, you might be perfectly happy with it as is. Mine was rusty and had some broken parts. That was OK since I just wanted the motor, but I never tried the complete saw to make a comparison with my older MBF.

    To answer your question about compatibility, the most common DeWalt with in interchangeable motor is the 925. It's actually the motor yoke which determines interchangeability. The 925 has all the desirable features from the old yoke design, but happens to fit the newer motor. I believe that 925s were made in '59 and '60. They are more squarish than the older saws, but still all cast iron. They also have the motor switch on the front of the arm, which is nice. I see them all the time on our local CL for $75-150. There are a bunch of less common DeWalt RASs which are probably interchangeable as well. If you come across one and aren't sure, the guys over at the other forum can probably give better advice.

    My reason for wanting to change motors is that the older 110v saws typically had 1/2-3/4 HP motors which (in my experience) are prone to stalling and require a smaller blade. The 7770 has something like a 2.2HP motor and will spin a 10" blade, giving a deeper crosscut and more blade choices.

    Please let us know if you get the saw. Old RASs are positively addictive.
    Last edited by david brum; 07-11-2011 at 1:37 AM.

  7. #7
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    Had one for a few years. Loved it. Was offered more than I paid for it new, so I sold it. Went through four other saws till I ended up with a 7790, the 12" version. Love it.

    That's a great price for that saw, in the condition you describe.

    Rick Potter

  8. #8
    Well I purchased the saw for $75 and it seems in pretty fair shape, even though I haven't had a chance to check it out good other than to make sure it ran. It states on the motor it is a 3 HP. The table looks like I will need to replace it. The carriage? seemed a little stiff at first but is smoother after I worked it a little. The manual states not to oil the bearings or rail. Taped to the manual was the original receipt for 499.99 Nov 1987.
    Will try to post pics.dewalt RAS1_2.JPGdewalt RAS1.JPGdewalt RAS1_1.JPG

  9. #9
    David, thanks for the info, that the 7770 motor will fit a 925. I found a mint 925H (with the original tableboard) for $50 at a Salvation Army. It was occasionally cranky when starting so I had the motor professionally serviced for another $50. It really zings now and runs so smooth that I can stand a penny on edge on the arm, but it would be nice to have a bit more power and blade choices. As it is, I've been using a Freud TK604(?) 8-1/2" sliding mitersaw blade, and it seems to be a good fit for the saw at a reasonable price (~$35).

    I also have a Delta/Milwaukee Super 900 that was owned by a university machine shop. In 1958, it cost $256.95 complete with stand and casters. It also came with the original boards on it, and it's a nice saw that is a complement to the DeWalt.

  10. #10
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    Quote Originally Posted by Rick Potter View Post
    ...Went through four other saws till I ended up with a 7790, the 12" version. Love it...


    Rick Potter
    $75 for the DeWalt 7770 ain't bad! You can get your money back for the motor alone!

    If you ever run across the 12" 7790 RAS at a reasonable price ($200 or less) grab it. That is probably the last really good DeWalt made before consumerism ruled. The 7790 was also sold by Sears/Craftsman. Same great saw!

    ~~Chip~~
    Necessisity is the Mother of Invention, But If it Ain't Broke don't Fix It !!

  11. #11
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    Just for posterity, and ... correct me if I'm wrong, but ... I think conventional wisdom is that -- in general -- the round arm DeWalts are better than the square arms.

    But ... as an owner of a round arm DeWalt, I _could_ just be making that up

  12. #12
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    Just for posterity, and ... correct me if I'm wrong, but ... I think conventional wisdom is that -- in general -- the round arm DeWalts are better than the square arms.

    But ... as an owner of a round arm DeWalt, I _could_ just be making that up
    I read that also, Neil. I think that definitely applies to the newer DeWalt RASs with square arms. I seem to remember reading that the earliest (pre 1964) square arm RASs actually had some improvements over the older saws, such as beefier bases and less finicky table adjustments, without giving up any of the good features.

    My saw is an MBF (round arm) with a 925 yoke and 7770 motor, so I can't say for sure if a round arm behaves differently from a square one, but I doubt it. If I had the room, I'd get a 925 just to see. The giveaway prices on craigslist make me crazy.

  13. #13
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    David, thanks for the info, that the 7770 motor will fit a 925. I found a mint 925H (with the original tableboard) for $50 at a Salvation Army. It was occasionally cranky when starting so I had the motor professionally serviced for another $50. It really zings now and runs so smooth that I can stand a penny on edge on the arm, but it would be nice to have a bit more power and blade choices. As it is, I've been using a Freud TK604(?) 8-1/2" sliding mitersaw blade, and it seems to be a good fit for the saw at a reasonable price (~$35).

    I also have a Delta/Milwaukee Super 900 that was owned by a university machine shop. In 1958, it cost $256.95 complete with stand and casters. It also came with the original boards on it, and it's a nice saw that is a complement to the DeWalt.
    Sounds like good fun!
    Last edited by david brum; 07-11-2011 at 10:18 PM.

  14. #14
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    That saw is in amazing shape, Neal. It even has the blade guards and the key. Cool. I'm jealous of the 3HP motor.

    The generally accepted fix for stuck roller bearings is WD40, more to free them up than to lubricate them. You don't want anything that sawdust can stick to.

    If you don't have one, you might want to check out the Mr Sawdust Radial Arm Saw book. It was written by one of the original demonstrators for DeWalt saws in the '40s and '50s. It tells you all about how to build a proper table, accurately set up the saw, etc. Good stuff.

  15. #15
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    Great score, Neal.

    As was said, you can't go wrong. At that price, if you decide you don't like it, you can probably double your money.

    When you build your new table, set up the saw completely before cutting into it. If I may make a couple suggestions....

    1: When you follow whichever instructions on setting it up..skip the part on dishing out a furrow for ripping. Lock that baby at 90 degrees and keep it there. I use mine for crosscuts only. If you have to ...make a jig to do angle cuts, and save your table.

    2: I see your saw came with the guards for the blade. Keep at least the one on the left side. The one on the right is good too, but it's not as easy to get near the blade from that side.

    3: My saw has a 3" high fence, with a t-slot for a stop, and a tape on the top. The way to use the guard with this kind of setup is to make the fence (mines about 4' long on the left), install it a few inches to the right side, and cut a slot through it. Then, move the fence over to the left till the guard slips through the slot. Tighten the fence, and cut the blade slot. This gives you a nice tall fence that the guard does not have to climb over, as well as a zero clearance blade slot. Finally....install the tape .

    There are other ways to do it, but this one works for me.

    Rick Potter

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