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Induction V. Universal Motor


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I have finally found some space for a few big tools and am thinking of getting first a table saw (I also do non-guitar woodworking), and then a band-saw. I understand that induction motors are more powerful and quieter; but, damn, what a premium in price! :D

What are people's real world experiences with universal motors. For the high precision tasks that guitar making requires, do the universal motor saws just not cut it? (yes, I intended that pun :D ) Seriously, for an amature that is only working on ocasional project on the weekend, will I be sorry that I bought a $250 universal motor saw instead of a $750 induction motor saw? For me $250 is a no-brainer, $750 I will have to agonize about for months.

Also, I live in one of those soul-less, brand-spanking-new, San Diego development communities. There are no pawn shops or guarage sales where some widow is unloading a 1950 14" bandsaw for 25 cents. At least not that I know of. So new or eBay seem to be my only options (unless someone has a San Diego specific recommendation).

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Which saws in particular are you looking at? I bought a $99 Delta tablesaw from home depot a long time back to take on site for carpentry jobs and such. I was actually rather pleased with it, too. They are ver simple machines, and with a good quality blade and some patience, they can deliver good results. For a bandsaw, though, you will probably be better off with the $350 Grizzly 14" or equivalent.

Personally, I prefer my 1943 Delta bandsaw and 1946 Unisaw that I bought from the widow down the road. :D

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The accuracy issue has to do with the fact that most universal motor saws are direct drive. That's inherently less accurate than having a separate saw arbor with quality bearings. Motor shaft bearings aren't designed for direct loads of that kind. Cheap direct drive saws are okay for jobsite construction work but not good for precision work.

You probably already know this, but forget the horsepower ratings. Universal motors are usually rated at a peak temporary maximum horsepower developed. A Delta Contractors Saw with its 1.5 hp induction motor will easily outperform a universal motor rated at 3 hp. And even a 3 hp universal motor in a belt drive saw doesn't have the power to cut through 2 in thick hardwoods without a struggle. Then there's the issue of longevity.

AFAIK you can still buy a Delta Contractors Saw new for about $500. Motor aside, the quality of the other components will be much better and you'll have a decent rip fence. If that's not in your budget, look around for a used one. You can get quality blades (not cheap contractor blades) for well under $100.

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Very true about the HP ratings. Most of these saws use the same motors as a large router. Rated at 3hp, but only drawing 15 amps at 120v, so really more like 1 hp. And they are not direct drive, either. Those motors spin real fast, and they have a reduction drive, usually a cog belt to get the blade speed low enough. So it doesn't rely on the motor bearings. Still not as sturdy as a contractor type saw, but not that bad either. For the money, the little benchtop ones are a pretty good value, and will do ok for occasional light use. The bigger universal motor saws, the ones masquerading as contractor saws, even with cast iron tops, are not much better, and cost a lot more. Better to spend a little more, and get an induction motor saw at that point.

Edited by orgmorg
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