Dewalt 7790 Type 6 radial arm saw

[DennisCps]

RE: Dewalt 7790 Type 6 radial arm saw
I own a 12” Dewalt 7790 Type 6 radial arm saw that I have not used for several years. I started using it again recently and it was running fine for a while but lately started shutting itself off on overload. The amp meter was all over the place when I tried to check the starting and running amps. I went to a shop and had the capacitor and the overload checked and they are okay. In fact I had a new capacitor on hand so I replaced the old one anyway but it is still acting the same.
Would anyone know where I can get the information on what the windings resistances are so I can ascertain that they are okay and are not shorted or leaking current? Also, is there a place I can purchase a new motor if I need one and will be worth the trouble buying a motor rather than buying a new saw?
The saw has 3.5HP motor, 120/208-240V, 17/8.5A, 3450RPM, 86531-59 Winding, 86532-00 Motor No., 52170196 Serial No., 250 Frame, 60 CY, CLASS B, Duty INT.
I would appreciate someone’s help. Thank you.
My email is: ddkswk@netscape.net
Dennis

[pprobus]

The first place I would go is to the DeWalt RAS forum on Delphi:
http://forums.delphiforums.com/n/main.as...butcher%2Fstart

You may also try www.owwm.org and ask on their forums.

As far as the 7790, unless you can afford a brand new Original Saw Company saw, there is only one option for buying new, that I am aware of and that's the current Craftsman saw which is not highly regarded at all. Delta has stopped making their RAS's since being purchased by DeWalt/B&D's parent company. I think most folks would say you should try to do what you can to rescue your current 7790 as there is no equivalent "new" out there. The 7790 is kind of like the old Delta contractor saw, the closest equivalent OSC saw to what you have would be more like a Delta cabinet saw by comparison, but even a Delta cabinet saw would be cheaper than the 12" OSC saw. If you find you can't rescue your current RAS, the alternative would be either to find a used replacement motor on the 'Bay, OWWM or the Delphi forum I posted the link to, since you can't buy a new replacement motor for the 7790, or buy a used saw that runs. Equivalent or better used saws would be a DeWalt GW or 1030 (both are round arm, older predecessors to the 7790 and are generally higher regarded by many than the 7790's) another 7790, I believe the 1500 might be an older version of the 7790 before it was re-badged to "7790" but otherwise unchanged, there are also saws numbered in the "35xx" range that are essentially 7790's, although some are 3 phase. I would steer clear of the MB line and 925 line only because you will likely be disappointed in their power (other than being under powered, they are sought after due to their accuracy). Pretty much any Delta/Rockwell turret arm RAS would be the equal to DeWalt as far as accuracy, from my understanding (I have never used one, can't say personally). Used OSC saws do come up occasionally and I have seen decent deals.

Also, I forgot to mention earlier, Wolfe Machinery can re-wind the motor, but it is a premium, you could likely get another running saw for the cost, if I remember right. It is my understanding that because of the way DeWalt made their saw motors, most motor shops will not rewind them. Not sure if its because special equipment is necessary or what, but most of the posts I have seen regarding getting the motor rewound locally, ended up in frustration. Not to say you shouldn't still try, I would still try to find a shop to at least give me a quote on rewinding the motor, if I were in that position, just to see if I could find anyone willing to do it and to see how much the cost would be.

Good luck, hopefully, its something really simple.
Paul

PS, it could be accumulated saw dust causing problems. Have you tried tearing down the motor to clean out the dust? I think that's where I'd start before going further down the road of assuming a winding is bad. As my dad used to say, eliminate the easier to fix problem first then go on to the next easiest fix, etc.