Checking a used table saw arbor

[Matt Day]

Sorry for multiple threads on this saw purchase, but I'm going to buy a Bridgewood BW-10TS; pending a couple more checks. The blade installed on the saw was pretty worn out and I don't think parallel to anything (miter slot or fence) and had noticeable wobble at slow speed. I couldn't take the blade off b/c the seller just let another buyerwalk off with the wrenches:rolleyes:. So I'll bring a good blade and wrenches with me when I go to pick it up.

If I simply install a good blade and the wobble goes away for the most part, is this enough of check that the arbor runout and everything is okay? I'm worried that if it's not the blade, I might be in for a lot of work to fix it.

Thanks

[Mike Goetzke]

Just bring a dial indicator with a magnetic base and check the blade run-out (arbor flange face would be better).

[Myk Rian]

If I simply install a good blade and the wobble goes away for the most part, is this enough of check that the arbor runout and everything is okay? I'm worried that if it's not the blade, I might be in for a lot of work to fix it.

Thanks
Sounds good to me.
You will also want to check the arbor and see if it moves in and out any. That may be hard to do with the motor putting weight on it.

[Ray Newman]

The dial indicator will be of help. But after buying it, I would still check the bearings again, esp. since the blade appears to you as “worn out" The saw could have seen some hard use.

An effective way to check the bearings is to utilize a stethoscope. You can make one, or if you know a mechanic inquire as to whether he has one.

First unplug the saw, remove the blade and next the cast iron top. remove the belt(s) from the arbor pulley.

Next take about a 1" dia. hardwood dowel (a section broom handle will work well) about 30" long & hold it on the arbor where the bearings are located. Place the other end in your ear & have someone turn the arbor by hand and listen carefully for any grinding noise, which will be easily heard by the ear. I've done this & the noise is very distinct & easily heard. I also spin the arbor in both directions & @ different speeds.

I think you could also do the above w/ a gloved hand to spin the blade.

Sometimes, all the bearings are bad, other times only one. But if you need to replace only one bearing, replace the other as it could very well could have been under stress from the worn bearing & will be prone to failure. Always buy the best grade of bearings possible.

[Matt Day]

I wish I had a dial indicator and magnetic base, but I don't. It's a bit late to order one online where I normally would purchase one. Where can I find one locally? Advance Auto, Lowes?

Is it critical I have this before I buy it, or just when I'm fine tuning the setup at home?

[jeff begin]

The dial indicator will be of help. But after buying it, I would still check the bearings again, esp. since the blade appears to you as “worn out" The saw could have seen some hard use.

An effective way to check the bearings is to utilize a stethoscope. You can make one, or if you know a mechanic inquire as to whether he has one.

First unplug the saw, remove the blade and next the cast iron top. remove the belt(s) from the arbor pulley.

Next take about a 1" dia. hardwood dowel (a section broom handle will work well) about 30" long & hold it on the arbor where the bearings are located. Place the other end in your ear & have someone turn the arbor by hand and listen carefully for any grinding noise, which will be easily heard by the ear. I've done this & the noise is very distinct & easily heard. I also spin the arbor in both directions & @ different speeds.

I think you could also do the above w/ a gloved hand to spin the blade.

Sometimes, all the bearings are bad, other times only one. But if you need to replace only one bearing, replace the other as it could very well could have been under stress from the worn bearing & will be prone to failure. Always buy the best grade of bearings possible.

When wrenching on his cars, my father used to improvise a stethoscope by using a long, flathead screwdriver (putting the handle end up to his ear). I don't know how that would compare to the dowel method, but if you don't have a dowel handy it might be more convenient.

[glenn bradley]

If you put the known-good blade on and the visually obvious wobble goes away, odds are in your favor that the blade just got whacked. The downside question is, how did the blade get whacked and did they used to run the saw with the blade like that, etc.

Harbor Freight sells magnetic bases and so-so dial units for pretty reasonable. I tilt the saw to 45* or more when checking runout. This presents the flange better and makes the testing easier for me.

[Ray Newman]

Jeff that will work too! I 1st learned of the wood dowel stethoscope from an old mill wright.

[Chris Konikowski]

Jeff that will work too! I 1st learned of the wood dowel stethoscope from an old mill wright.

I do that with screwdrivers or extensions to listen to engines, injectors, pulleys/ bearings, etc. Good ole trick...