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Table saw burned out?

gj13's picture

I have a low end Craftsman tablesaw. It cost around $180 new about 5 years ago, to give you an idea.

Just now it started making a loud rattling noise so I turned it off. Everything looked o.k., so I tried it again. Made a few more cuts. The rattling noise came back. I immediately turned it off. Now there's an acrid smell permeating the room.

I guess five years of hard labor was too much for it. Never mind if it's worth repairing. Is it possible to repair?

sawdustmaker's picture

(post #93678, reply #1 of 28)

Define the rattling noise. My guess is the acrid smell might be electrical, but the rattling might be something different altogether. Most anything can be repaired, but the question is if the time and money are worth it for that saw. Your money might be better spent towards a new saw, or at least a quality used one.

gj13's picture

(post #93678, reply #5 of 28)

Well, thanks everyone for your advice. I'm leaning toward replacing it. Not 100% sure, but pretty sure.

PeteBradley's picture

(post #93678, reply #6 of 28)

Well at least give us some more hints on what went wrong with it...

Pete

gj13's picture

(post #93678, reply #7 of 28)

Well, I don't know much about electric motors and don't really have the time to delve into them.   But I can say this:  the blade still turns when the motor's on, and makes an ear-splitting chatter, even with earplugs in.   The blade feels as snug as it did before.  The machine gives off a strong, acrid 'electrical' smell that fills the room. 


It's not belt driven, it's direct from the armature. (if that's the right word). 


What I need to do is take it apart and see what there is to see.


 

PeteBradley's picture

(post #93678, reply #8 of 28)

Sounds like the rotor is scraping against the windings somehow.  This is probably one of the table saws with a power-tool type motor in it (basically a circular saw turned upside down).  In any event, it won't run for much longer and running it will likely increase the amount of damage.  I'm sure replacement parts are available from Sears.  If you're feeling adventurous and the cost is reasonable (doubtful) it's probably fixable,  but if you've been thinking about an upgrade, this would be a good time.


I've never had good luck with Sears/Craftsman-branded power tools, with the exception of those made before 1970 or so.  Even if it means saving up for a while, it's worth spending the extra bucks on a quality tool that will last.


Pete

gj13's picture

(post #93678, reply #9 of 28)

O.k.
My father-in-law, an engineer, convinced my wife (also an engineer) that I should try to fix it before buying a new TS. It is what it is.

Took out the motor, took it apart. Looked it up in the manual, and it looks like I need a new bearing bushing, which is the bearing assembly where the motor mounts to the housing.

$2.16 on Craftsman.com

As much as I wanted a new saw, for two bucks I can't justify it.

highfigh's picture

(post #93678, reply #16 of 28)

If there are so many engineers in your family, why didn't they try to redesign it? I'm a little surprised by this. lol

"I cut this piece four times and it's still too short."

"I cut this piece four times and it's still too short."
gj13's picture

(post #93678, reply #17 of 28)

You know? You've got a point there.
My father-in-law is a construction engineer, my brother designs motorized wheelchairs, and my wife has a PhD in making steel. And yet, all I get from them is sympathy.

highfigh's picture

(post #93678, reply #18 of 28)

You obviously didn't submit the requests, in writing, in a timely fashion. Issue a change/repair order and see what happens.

"I cut this piece four times and it's still too short."

"I cut this piece four times and it's still too short."
gj13's picture

(post #93678, reply #11 of 28)

O.k. 


I've got the bearing on order.  Tried to get the bad bearing off.  I can't do it.  I looked online and at stores (Sears and Harbor Freight) for a bearing puller.  Bought the smallest one I could find (from HF).


Nothing is small enough to fit between the bearing and a copper winding.  Took it to a neighbor who is a self-employed builder/remodeler.  He didn't have a tool and didn't really know how to get it off. 


To his credit, he offered me the use of his portable TS.


I tried wedging a screwdriver in there just to see.  All it did was chip a plastic collar on the copper winding.


Any other ideas?


Thanks in advance.

PeteBradley's picture

(post #93678, reply #12 of 28)

It sounds like you're dealing with a ball bearing. I was thinking sleeve, so this motor is a step up from what I expected. If I'm totally misunderstanding the part, please post a link to an exploded view or describe it. If not, read on...

The official tool is called a bearing splitter. It clamps around the bearing, and then you pull the splitter with your puller. They're pretty easy to find online and you'll never regret owning a puller or a bearing splitter. Sears may even carry them, not sure.

There may be alternatives. How much space do you have behind the bearing? I've had some luck in the past with hanging the shaft vertically with two metal bars of appropriate thickness behind the bearing and sitting on crossbars (the jaws of a big vise are good, or wood), then gently tapping the shaft loose. You need to avoid: 1) mushrooming the shaft (use a plastic hammer or a wood block with a metal hammer; 2) bending the shaft; 3) slamming the rotor into the floor when the shaft drops free. The bearing splitter is likely much safer and simpler.

Installing the new bearing is straightforward. You need a piece of pipe that just fits over the shaft. It's important that the pipe only contacts the inner race (ring) of the bearing or you'll destroy it during installation. The plumbing department of your local big box store is a good source. Make sure the shaft is clean. Slip the bearing onto the shaft, then the pipe. Rest the bottom end of the shaft on a piece of hardwood. Insuring that the bearing goes on straight, tap it into place by gently tapping the pipe. Usually there's a shoulder on the shaft designed to stop the bearing when it's all the way on, but check before you start.

Pete


Edited 12/20/2005 7:32 am ET by PeteBradley

philip's picture

(post #93678, reply #13 of 28)

Pete, i have had to manage without a bearing splitter a few times , by cracking off the outer ring of the bearing by squeezing in a vice. That leaves the inner ring-which can be cut almost through with an angle grinder-if you make two cuts it usually just drops off.
I don't like what he says about screw drivers and copper windings.....

Philip Marcou

Philip Marcou
PeteBradley's picture

(post #93678, reply #14 of 28)

Yeah, there are some more brutal options, but with greater risk of collateral damage.

Pete

Walker1's picture

(post #93678, reply #2 of 28)

    Craftsman tablesaw accessory .          Home Fire Extinguisher        :laugh: :D  :laugh: :D  :laugh: :D 


             Just Kidding.   Cheers. Shawn


 


  ( I didn't make that one up, but I thought it was pretty funny.)


              


 


                             

TELEMIKE's picture

(post #93678, reply #3 of 28)

I have an old craftsman 8" saw that I bought in 1974. It is a "motorized saw". That means that the blade is mounted directly on the motor arbor. My newer Jet saw has a 10" blade on a belt driven arbor. I would not be surprised if you have a motorized saw and that the motor is toast.

Motors like that are not really repairable. Go to the craftsman website and find spare parts for your saw. They should include the motor.

Is it worth fixing? It's not much good as a woodworker's primary saw. I kept mine all these years even when I got rid of the later bought but older craftsman 10" contractors saw. I keep a 3/4" dado blade in it and it fits under a counter top. It's worth it to me even considering how infrequently I use it because it's not worth much even on overpriced ebay.

I also put a 7" skill saw blade in it when I need to cut aluminum or a sheet metal blade when I cut galvanized sheet. Better to kill this saw than the good one!

How much is the motor? Is it worth keeping given the space you have and the time you spend woodworking? Do you ever use a dada? Can you afford a good saw? Folks here have LOTS of opinions on better table saws - just search the archieves or make some kind of inflammatory statement.

highfigh's picture

(post #93678, reply #15 of 28)

Just about ANYTHING is repairable, it just a matter of whether parts are available.

This sounds like it could be a bad bearing. They're lubricated, rattle and smell bad when the bearing burns up. A good motor rebuilder should be able to get it up and running again, but it's not inconceivable that the repair could be close to $100. If the arbor needs to be replaced, it would probably be prohibitive.

"I cut this piece four times and it's still too short."
"I cut this piece four times and it's still too short."
PeteBradley's picture

(post #93678, reply #4 of 28)

The first step is to figure out what's busted. I don't know if this is a direct drive saw or one with a belt. If there's a belt, make sure it's not vibrating and whacking into something when it runs, which would explain the rattle and the smell, and it would be a cheap fix. Unplug the saw, grab the blade, and see if you can shake the blade up and down. If you get noticeable movement, the arbor bearing is shot.

If the arbor is also the motor shaft, you would need to press a new bearing into the motor housing. This isn't terribly difficult, but it can be a nuisance and it's a different skill from woodworking. On the other hand, if the motor bearings in a saw like this are shot, you don't have a lot to lose.

One good thing about Sears is that they genereally have exploded views and sell parts even for their lowest-end machines. If you can find a link on Sears site for this model, that would help to diagnose it.

sailalex's picture

(post #93678, reply #10 of 28)

Before you buy a new table saw, take a look at a thread I started (title I think was Festool TS55, or something similar). The thread asked questions about the new Festool saw BUT through that, I learned about an EZ Smart system that does away for the need for a TS. After looking at the responses I concluded if my TS went I would get one of these before investing in a new TS.

vinsulla's picture

(post #93678, reply #19 of 28)

My experience here in Canada, was that repairing the motor cost more than a new one, not including my time and driving a round, a new motor was nearly as much from Sears as a similair  new saw was, and so I bought a   new Unisaw and have never regretted it.  My first saw was a 1937 Beaver   which was actually better than the Sears.


Ken

PeteBradley's picture

(post #93678, reply #20 of 28)

It depends. This is a bearing swap. Getting it repaired might be prohibitive, but replacing a bearing is only moderately difficult and it's a valuable skill that will last a lifetime.

When you trade up, it would be nice to sell the old machine instead of sending it to the landfill.

Pete


Edited 12/23/2005 9:55 pm ET by PeteBradley

vinsulla's picture

(post #93678, reply #21 of 28)

I am a retired mechanic and I worked on tools of all kinds for a rental company, and some toole are made to be repaired very easily by anyone almost.


Others are made so only the factory can repair them and others are made to replaced not repaired. Bearings which are meant to be removed with a bearing spreader have to have a solid backing for the knife like jaws to press against.


Ken

PeteBradley's picture

(post #93678, reply #22 of 28)

We're well off the topic of woodworking but I'm curious -- what types of bearings don't work with a splitter (aka spreader or separator)? For the machine bearings that I've pulled, as long as there's no need to remove the bearing in a reusable form, the only requirement is to get something behind the bearing that's strong enough to take the pull.

I'm guessing that you're referring to some automotive bearings that will come apart if you only pull the outer race. I haven't had this happen with any single-row machine bearing, but who knows?

Pete

vinsulla's picture

(post #93678, reply #23 of 28)

  Countless types won't  "work" with a splitter.


I was referring to your "wedging a screwdriver in..." and something about chipping a plastic collar, also something about motor windings was mentioned.


  If there is no room for puller jaws, and there is something solid  behind the bearing a splitter is forced in between the the bearing cone and whatever is behind, hopefully not plastic, by tightening the nuts on the bolts what hold the two knife like jaws together, forcing the bearing to slide down the shaft.


Anyway your original question was  Is it possible never mind practical.


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 

PeteBradley's picture

(post #93678, reply #24 of 28)

You're confusing me with the original poster. I was suggesting to the owner of the saw some methods that might be more effective than the screwdriver.

It also appears that I was not clear in my suggestion on the splitter. You can set the splitter in place behind the bearing and then pull it with a puller, as shown in the attached pic.

I think we've now beaten this OT thread to death. A better place for further discussing machinery repairs (though recent machines are considered OT) would be www.owwm.com.

Pete


Edited 12/29/2005 5:43 pm ET by PeteBradley

PreviewAttachmentSize
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splitter_and_puller.gif5.04 KB
vinsulla's picture

(post #93678, reply #25 of 28)

excuse me

philip's picture

(post #93678, reply #26 of 28)

.....beaten this thread to death"- not quite, Pete. If the bearing is as I suspect, hard up against the armature then that splitter you picture will not fit, and if it did, would most likely cause damage to the very delicate armature. I have used the method I described a few times with successs-the only risky part is cracking the outer ring in a vise.
I don't see why this sort of topic should be discussed exclusively elsewhere-machines are part of woodworking-so is metalworking to some extent. And some people save money in various ways.

Philip Marcou

Philip Marcou
PeteBradley's picture

(post #93678, reply #27 of 28)

OK...in case it's not obvious, there has to be some clearance for a bearing splitter to be used, and you shouldn't force it in a situation where you could break something you want to keep.

Lots of potentially viable methods and their pros/cons have been posted here. If the original poster got the bearing replaced, congratulations and please post a gloat!

Since there seems to be a fair bit of interest in this topic, I'm attaching a picture of the rotor from the 1HP Repulsion-Induction motor from my late-1940s Delta 20" band saw. The picture doesn't do justice to the hand-tied wrapping and wedges. They don't make 'em like this any more.

Pete


Edited 12/30/2005 9:07 pm ET by PeteBradley

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scott345's picture

(post #93678, reply #28 of 28)

I burned upa craftsman table saw like the one you mentioned. It was a total waste. No one would even bother to fix it. They said it was a throw away that the motor is sealed or something like glued together, and not meant to be repaired. I took it as the perfect excuse to buy a new saw.