Should I repair an old table saw motor? I have an old Craftsman contractor’s saw that now has a base on it with dust collection and Incra fence with a cast iron router table extension. I replaced the bearings on the arbor, which is heavy duty. I also repainted the base. You get the idea–lots of TLC.
However, I don’t have much motor knowledge. The old motor is 1H, 12amps with a cast-iron housing. But it growls and grinds. Since the spindle is still running straight, I want it tuned up but I don’t know what’s involved with a motor that may be 50 yrs old. I know the first reaction is to replace it, but I don’t think I’ll ever buy a motor built as well that is new. Since you can see I’m married to this thing, any suggestions for making sure the motor is still going to work and then any for what to make it work? Nobody in Big Spring, Texas, is willing to look at it.
A big thanks,
Jeff Liles
Replies
Since you already have $ and love invested in the machine, maybe replacing the motor is the right idea after all. A new Baldor 2hp motor with machined pulleys and a link belt will turn that saw into a dream machine. Fixing the motor will still leave you under powered and since nobody is willing to touch it, you're kind of stuck unless you try to fix it yourself. You may find that you can't get parts or that the only way to get it back in order would be to have extensive machine work done. The end result would be a more expensive motor that is no where near the quality of the Baldor. It will run you around 200 - 250 for the Baldor if you shop it right.
Steve - in Northern California
But it growls and grinds.
Sounds like all it needs are 2 new bearings. Go to any bearing house for replacements, or auto parts store even.
I have to agree with Steve. If you start replacing parts on a motor that old (if you can even find them) might nickle and dime you and you may spend as much as on a new motor and not have a new motor. I call this the weakest link phenomenon and it's happened to me too many times until I've learned. It goes like this: you replace a part that's broke and the next weakest part breaks. You replace it and ... you get the idea.$ Bill
Jeff, I have a virtually new Jet 1.5 HP motor that I may be wanting to sell pretty soon. I bought it for a Jet Contractor's saw that was given to me, because the original motor was burned out. I'm having trouble with the saw itself (not the motor) and am seriously thinking about just trying to get some of the money out of the motor, and ditching the saw for a new one.
The motor retails somewhere in the $250 range, but I got it for around $190 (new). If you decide you want a new motor, and think this might work for you, drop me a line.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Completely off the subject, what's your Jet tablesaw problem? (Other than sloppy handwheels) I have 10" contractors saw with stamped steel wings. I keep upgrading it little by little, lusting after cabine t saws I can't afford. I've added a mobile base, link drive belt, TS Aligner trunion adjusting widgets, zero clearance insert, etc. My only real complaint is that the saw is underpowered. I got all kinds of advice a while back on upgrading to 220 volt, or replacing the motor with a 2hp Baldor. Are you going to keep the saw or hang it up?
Hi q-sawn. Oooohhhh I was afraid someone would ask! The problem with the saw has been cussed and discussed ad nauseum in a completely unrelated thread elsewhere, about 6 weeks ago or so. (I shouldn't hi-jack yet another thread LOL) The blade won't come anywhere close to parallel to the miter slot. With Steve's and others more-than-welcome help, I literally took it apart. Turned it upside down, and took the entire carriage assembly out and apart to try and track down the problem. I stopped short of enlarging the bolt holes in the trunnions though. The only possible cause I could see is a possible mis-machining in the left stretcher bracket in the front trunnion, which would make that stretcher bar not parallel.
This is a several-years-old used saw I got from a framing shop in Seattle. At some point in time, he had it set up parallel, but I have a feeling he must have muscled it into line, and it probably popped back out again. I now have my miter bar and fence set up so that at 90 degrees, I can cross-cut and rip OK. It's terrifically out-of-range at any kind of bevel though.
There's a possibility I can get a tech at Jet to take a look at it, if I load it up in the van and drag it over to the Auburn plant. I haven't called them about this. If that's a no-go, I'll keep cutting at 90 degrees, using my cheap little miter saw when I have to, and save up for a new saw.
Although the contractor's saw are a great price point for a tablesaw, I find myself shaking my head in disbelief at an adjustment procedure that requires a hammer and a 2x4, for something that's hopefully going to be within .02" or whatever. Nuts! The only other thing I can think of to do is fork out for 2 new stretcher bars and a new front trunnion and install 'em, see what happens.
Sorry you asked? I thought so!! LOL.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Jamie, what do you know about PALS... I hear they are pretty good at solving problems like yours.. Well maybe not all of them but at least the Jets problems. LOL. http://www.woodcraft.com search on pals and forget the stupid, "could make that myself" dial guage just read about the PALS. Its a pretty lame description so if you need more just let me know after Saturday when I install mine.Steve - in Northern California
Hi Steve. I've seen the PALS and heard good things about them, here and at WoodMag. If my saw was fundamentally sound, I'm sure they would work fine. But it's not :-(
It is so out-of-whack that it's obvious there's something bent, mis-machined, or both, within the carriage unit itself. Will have to break down and take it to Jet if they'll talk to me. With it being a several-year-old saw, they might not be too happy to see me.
I think the only way the PALS would have helped with my other problems would be if they had been installed early in life and adjusted mercilessly every time I took a bad turn! LOL!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Wow, you know I didn't realize it was that bad. However, it would not suprise me at all if Jet welcomed you with open arms and even threw in a tour. I don't know, something just tells me that's whats gonna happen. Steve - in Northern California
Burlyman
My first inclination would be to split open the motor and see if it is the bearings. If it's the double extended shaft, cast iron end bell with cast mounting base type, you can see them from the outside by removing the felt seal retainer. Those ball bearings are probably unsealed on the outside and therefore easy to inspect/relube. I've replaced the bearings in a 1/2 hp from the early 60's in less than an hour, not counting time to source replacements. Most of the time was in cleaning (don't scratch the windings or wiggle any wires; some gentle compressed air for cleaning at most). I'd also suggest removing only the end bell opposite the built-in junction box. You can then slip the rotor out from that end without disturbing the start-winding switch and stator wire connections at the other end.
If you crack it open, at least you'll know why it's making noise. If it's totally shot inside, you haven't lost anything but a little time. And if you do upgrade to a newer motor in the end, you can always use the old one for a buffing or wire wheel. That's what my old motor does now. That built in on-off switch makes it ideal. To me it was worth the cost of 2 bearings and a little time.
TDKPE:
Thanks. I did crack it open, and I'll remove the bearings at each end of the spindle tonight. While I'm doing this, I'd like to find the brushes and replace. Maybe the contacts as well. But I don't know what these look like or where to find them. Ideas?
Jeff Liles
TDKPE - Those old bearings might be cleanable. Those on my old bandsaw were. I pried off the dust shield and soaked the bearings in lacquer thinner. They were totally filled with gunk and dust. After cleaning, I inspected them and the bearings were perfectly good. I put in new grease and reinstalled the dust shields. That was a year ago and they're still working like a champ.
PlaneWood by Mike_in_KatyPlaneWood
If it's an induction motor, it doesn't have brushes. But if it's a capacitor-start then it'll have a centrifugal switch inside. They'll sometimes make a racket. Don't know if you got to the bearings yet but they may be sleeve bearings. Some of the old motors were. As long as the windings are OK, motors aren't hard to fix. Open it up - it's fairly obvious what's what.
Unless it's a repulsion-start/induction-run unit (Unisaws from the 30's and 40's, for instance), there are no brushes. As for the contacts, look through the stator into the end bell with the junction box and wiring to the stator windings. There is a metal yoke with a wire soldered to the hinged end, and another wire to the stationary part. The contacts, if any, are under the yoke at the end opposite the hinge. But I wouldn't touch anything in there, if the motor starts ok. The insulation on that wire is pretty old and brittle, and you will probably do more harm than good by disturbing it. However, you should check the fly weights on the rotor, and make sure both springs are not broken. You should be able to hinge the weights away from the shaft against the springs, and the (bakelite?) bushing should slide freely with the motion of the weights.
As an aside, when the motor is at rest the weights are retracted, pushing the bushing and consequently the start circuit contacts together; as the motor picks up speed, the weights fly apart, retracting the bushing and allowing the contacts to separate. The sound you here as the motor slows is the (rotating) bushing being reengaged against the (static) switch assembly. And if you knew this already, sorry for the lecture.
Hope this helps.
Edit: I let this sit so long before posting it that others have said the same thing. Sorry for the redundancy.
Edited 5/8/2002 5:08:35 PM ET by TDKPE
TDKPE:
You were most helpful. Thanks to all. The bearings were sealed cartidges, and I was able to match them at NAPA auto parts. As for the rest of the insides, they turned out as you said. And everything else appears to be solid. So I think I can clean it out, put it back together and get it running. The 2 cartidges cost less than $25, and that is about all I want to spend for now. So ForestGirl, I will decline for now on the offer to by the Jet motor. Of course, I expect it to work once I put it back together. One more thing, those springs near the yoke, should I try to replace them even though they are not broken?
Thanks again. This should work and is why such a forum exists. TO ALL: these old, solid motors are worth repairing.
Jeff Liles
No. You'll never match both the geometry and spring rate. I'd just blow it out with air, wipe down the bearing areas and small parts, and reassemble.
look in the yellow pages under electric motors - rebuilding or something like that.
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