circular saw axial play

[pauleyman]

I have an older craftsman 315.108400. It does what I need it to do generally but I noticed the blade wobbling a little so I took it apart expecting to find a worn bearing. Nope. Looks new. What is happening is there is a slight axial play in the shaft. No part diagrams show what the problem might be. I'm not opposed to a new corded or cordless saw but I'm kind of a use what you have sort of person. I just put a new diablo blade on it and as one would expect I was like damn I didn't realize my old blade was so bad.
Thoughts on this possible repair or should I start researching new saws? I also tend to go overboard and I can see myself with a monster worm drive and then figuring out I bought too much saw. Think Tim Allen...yeah thats probably me.

 

[seber]

Even if you could find it, a new shaft would cost more than a new saw.

 

[RTM]

Looks like the armature isn’t available anyways.

https://www.searspartsdirect.com/model/54q43sj7u5-000247/craftsman-315108400-circular-saw-parts

 

[WinMod21]

I have an older craftsman 315.108400. It does what I need it to do generally but I noticed the blade wobbling a little so I took it apart expecting to find a worn bearing. Nope. Looks new. What is happening is there is a slight axial play in the shaft. No part diagrams show what the problem might be. I'm not opposed to a new corded or cordless saw but I'm kind of a use what you have sort of person. I just put a new diablo blade on it and as one would expect I was like damn I didn't realize my old blade was so bad.
Thoughts on this possible repair or should I start researching new saws? I also tend to go overboard and I can see myself with a monster worm drive and then figuring out I bought too much saw. Think Tim Allen...yeah thats probably me.

No idea on the axial play, sorry to say. Were you able to remove the arbor? And you're sure it wasn't a warped blade?

Note: Either all or most all worm drives are made with magnesium metal components these days, so they're much lighter than older worm drives used to be. With Skil—the former King of worm drive saws—still considered the best, as far as I know, but they're also available from: Makita, Bosch, Dewalt, Rigid, Milwaukee, &c, in various weights, rpm's, torques &c.

 

[StillTooManyHobbies]

Is there a place to add a shim washer to take out some of the play?

 

[matt_i]

Also possible is that a keeper on one of the bearings is broken/warped/damaged, allowing the shaft to shift axially.

I could be wrong but I'm going to WAG that something like a set of electric motor ball bearings (single row deep groove) controls the axial thrust as well as the radial runout.

Iow, find (expose) the bearings, likely very close to diagnosing or solving the problem.

 

[pauleyman]

I'm looking at that. Armature isn't the problem as the blade doesn't mount to that. The reduction gear and shaft is the problem. Looks like the assmebly just wears over time and you can no longer buy replacement parts. I may try a small shim and see what happens. nothing to lose.

 

[pauleyman]

Also possible is that a keeper on one of the bearings is broken/warped/damaged, allowing the shaft to shift axially.

I could be wrong but I'm going to WAG that something like a set of electric motor ball bearings (single row deep groove) controls the axial thrust as well as the radial runout.

Iow, find (expose) the bearings, likely very close to diagnosing or solving the problem.

The blade doesn't ride on the same shaft as the motor. Any play in the motor itself wouldn't affect the blade. I'm guessing all circular saws (not worm) work this way. There is a gear reduction shaft and the blade is attached to that.

 

[KnurledNut]

This the one?

The gear/spindle rides in a sleeve in the gearcase. If the bearings are good, i would check this next.
The sleeve is a few bucks here:
https://www.searspartsdirect.com/product/pxrvbhm9rz-0009-315/id-968149-003

 

[RTM]

I'm looking at that. Armature isn't the problem as the blade doesn't mount to that. The reduction gear and shaft is the problem. Looks like the assmebly just wears over time and you can no longer buy replacement parts.

I saw the gear #22 on the one drawing, but couldn't find its mate (nor on the motor dwg), so wondered if it was to lock for blade change. Since you have it apart you can see the truth.

Shim can't hurt at this point.

 

[rsanter]

has it always been that way? or has it changed?
many power tools like this will use thrust washers to adjust this type of axial play, you could have wear from time/use or if there was a thrust washer it could be worn or eaten.

you can add a couple of thin thrust washers to take that play up no issues

 

[KnurledNut]

I saw the gear #22 on the one drawing, but couldn't find its mate (nor on the motor dwg), so wondered if it was to lock for blade change. Since you have it apart you can see the truth.

Shim can't hurt at this point.

It looks like the armature drives the gear.
The sleeve i mentioned in my previous post is part no. 8 in this diagram:

 

[RTM]

It looks like the armature drives the gear.

Yeah , I agree. At first glance I didn’t see it. The closer look today was a Yeah Might Be. Dang

 

[The Cobbler]

how much axial play do you have?
Circular saws aren't finishing saws. a bit of play is normal.
as mentioned, you can probably take up some with a shim washer or 2

 

[nadogail]

Shimming thrust washers is an old school way of reducing axial play.