[nickbatz]

It's a Craftsman 315.228310.

I used it today for the first time in a long time, possibly six months (don't remember exactly). It was okay for the first couple of cuts, and then all of a sudden it started slowing down and struggling with 3/4" oak - and not all the way through, I was cutting a rabbet-ish L out of it to make a picture frame.

Is it likely to be the blade? The motor purrs along fine, and this isn't one that wants to be lubricated (as far as I know anyway).

Ideas what could be going on?

TIA

 

[MadMark]

Is it thumping? The belt could have taken a set and become glazed.Check belt tension.
The bearings could be tight. Does it spin well by hand. (after unplugging, of course)? Take the belt off and see how well the blade and motor spin separately, if either is tight, change the bearings.
Try a link belt.
Check the motor brushes.
Throw an ammeter on the motor and check the draw. Ditto for incoming voltage.
All else fails, it's NEW SAW TIME! LOL

 

[MrUnix]

That saw has a pseudo-direct drive universal motor that has a plastic housing which also holds the rear bearing. If pushed too hard, the plastic will deform and cause bad stuff to happen - the worst being allowing the armature to come in contact with the windings, along with a really neat fireworks display of shooting sparks. They are also known to use really cheap bearings, which doesn't help.

How hard were you pushing the saw?

Cheers,
Brad

 

[MChang]

Is there burnishing on one side of the cut? Have you checked blade and fence alignment? Brian

 

[nickbatz]

No thumping, and again - the motor sounds fine. However, MadMark, I will put all that stuff on the troubleshooting list, just not at the top. New saw time? I dunno, this one is only 50 years old, it has to be good for more abuse.

There isn't noticeable burnishing on one side of the cuts, Brian, but that is a good thought - in fact it was the first thing I was wondering about. I will check the alignment.

 

[nickbatz]

Thanks guys, I appreciate the replies.

 

[MrUnix]

I dunno, this one is only 50 years old, it has to be good for more abuse.

Way past time to replace bearings, even if that isn't the source of your problem. They do have a limited lifespan, and typically 10 years is the time for replacement if not earlier. It's not that hard... there are only 4 screws holding the housing on. You can inspect the brushes and clean up the commutator as well once you have it open. All of these are maintenance items, and it appears yours is quite overdue for a little TLC

Cheers,
Brad

 

[nickbatz]

It's not really 50 years old, Brad, I was kidding. But it is probably 25 years old.

And bearings. If they're anything like the ones on my motorscooter when I had it... oy. You need a bearing puller, a press, and more time than I care to spend on this!

These days I'm not doing a whole lot of woodworking, other than making picture frames for my artwork.

Brad wrote: "How hard were you pushing the saw?"

Not hard at all. As I said, this was 3/4" thick wood and it struggled just to cut a slot in it. (Since this is going to be painted, I used scraps of red oak, walnut, and maple. No reason to buy new wood or cut into a big board that I can use for other things.)

 

[MrUnix]

And bearings. If they're anything like the ones on my motorscooter when I had it... oy. You need a bearing puller, a press, and more time than I care to spend on this!

No special tools should be needed... a bench vice and a wooden mallet will do the trick. They are common 6202's if I remember correctly (but pull and verify before ordering!!!) and very easy to replace. Even 25 years is a long time for a bearing. The problem with these are the plastic bits and the cheap bearings from the factory. If the bearings are starting to go or have leaked out their grease, they will get hot - even if you aren't pushing the machine hard - just normal operation. That will then let the plastic deform, which can cause all sorts of problems. If left to go long enough, it will completely deform and the motor will trash itself. At that point, you are looking at a new saw since a replacement motor costs more than the saw itself. Consider new bearings as cheap insurance - plus you can inspect the rest of the interior of the motor. Here is a shot of the rear bearing and a commutator that really needs cleaning!

Cheers,
Brad

 

[nickbatz]

No special tools should be needed.

Ah. Thanks.