What do dying bearings sound like?

[Longhorn Dave]

What does it sound like when they start to go? My Jet 1220 makes a rumbling sound that goes away only if I set the belt really loose. If it is bearings, do I need to stop immediately, or just keep going till they die, and replace? Any thoughts? Thanks in advance.

 

[Ken Grunke]

Well, if it IS a bearing, I'd have one all ordered and ready to put in. If you're not sure if it is or not, pinpoint the sound's location with some kind of audio aid, like a piece of tubing held to your ear, or a mechanic's stethoscope.
Then at least you'll know if it's the inner or outer headstock bearing, motor bearing, or something else.

 

[Longhorn Dave]

The motor is underneath, so I know thats not it. If it IS bearings, what do they sound like when they go out?

 

[Bill Turpin]

Use a large screw driver

Do not stick anywhere that it will hit moving parts. Press the end of handle to your ear flap. Press the point to the location of bearing. If good, you will hear a quiet smooth whirling sound. If bad, you will hear scraping, grinding, knocks, pops, etc. Check both ends of the shaft.

Do not ignore too long, you can spin the entire bearing. This is not good. You can also score the shaft.

Bill in WNC mountains

 

[Jake Debski]

What does it sound like when they start to go? My Jet 1220 makes a rumbling sound that goes away only if I set the belt really loose. If it is bearings, do I need to stop immediately, or just keep going till they die, and replace? Any thoughts? Thanks in advance.

Isn't the 12-20 is a newer model. How long have you been turning on it? It very well could be under warranty. I'm confident that you already made sure the belt was on the proper opposite pulleys. Anyway check that the grub screws(set screws) on the pulleys and hand wheel are tight and that the pulleys are properly aligned. with the motor pulleys. If these things all check-out then call Jet tech and ask what your next step should be.

 

[Odie]

Bad bearings can also sometimes (but, not always) be detected by taking all tension off the belt and just turning the spindle shaft by hand. If the rotation isn't smooth, and is a little jerky, that's a surefire way to determine that the bearings are bad.

If you can detect any kind of "play" in the bearings, they are bad. Bearings can wear either radially, or axially. If you can detect movement by pushing and pulling the spindle shaft along it's axial rotation, it's an indicator of bad bearings.

Also, you may want to install a piece of scrap wood to your spindle for this check of radial play: By using a lever (crowbar, ax handle, or something like that) against the mounted wood, you may be able to use your fingers to detect radial play.......it's also an indication your bearings are bad.

aplpickr has also given you a great suggestion about listening for scraping sounds. His screwdriver method will work to some degree, but most any automotive parts supplies have a stethoscope made for exactly that purpose....this is the same as Ken Grunke suggested. I use one of these frequently at my workplace, and can verify that they work very very well. I believe you can get a set for $10-$20.

Good luck

otis of cologne

 

[Longhorn Dave]

Thanks odie. There doesn't seem to any play at all. It is very strange to me. It just started making a rythmic noise in the midddle of a bowl. I found that as I tighten the belt, it gets worse, and if I loosen it, it goes away. Previously, I kept the belt tight, and never had any noise at all. Are bearings difficult to replace? I am a veteran, and I did enjoy your pics. I just missed Vietnam, and I have always had a strange fascination with it.

 

[Odie]

Thanks odie. There doesn't seem to any play at all. It is very strange to me. It just started making a rythmic noise in the midddle of a bowl. I found that as I tighten the belt, it gets worse, and if I loosen it, it goes away. Previously, I kept the belt tight, and never had any noise at all. Are bearings difficult to replace? I am a veteran, and I did enjoy your pics. I just missed Vietnam, and I have always had a strange fascination with it.

Jake Debski's idea of checking the tightness of your pulley set screws is a good idea......did you check on that?

Hard to say how difficult it would be to change out your bearings, since I'm unfamiliar with your machine.......but, it shouldn't be too hard. I've never needed to change the bearings on my Woodfast.....yet!.....but, I'm sure it'll come down to that sooner or later.

I do change out bearings and races on the machine I operate at work......about once per year. If you have cone bearings, and if these bearings can be replaced without the need for races, that makes the job lots easier......otherwise you'll probably need a slide hammer race puller to do the job. You probably won't need any special tools to install new races......the old race reversed on top of the new one, plus a dead blow hammer is all it will probably require.

All of that is strictly theoretical, because I have absolutely no idea what the make-up of your lathe is.....and comes from my experiences with the centerless grinder that I use at work.

If you have ball, or roller bearings, they are likely a sealed unit, and just punching out the old and installing the new similarly to the races described above is probably all that will entail.

Now, I'm beginning to wonder about how to replace the bearings on my Woodfast. Ha! I'm headed out there to take a look.......

Everything is probably made in such a way that the spindle shaft can only be removed in one direction, and reinstalled into the new bearings the same way.

I'm going out to check on mine........

otis of cologne

PS: I've always felt a great sense of pride in my country, those men whom I lived with, and worked with during my tour of duty.......

 

[Longhorn Dave]

I know how you feel about the men you served with. I feel the same way, though it has only been 4 years since I retired and I didn't go to a war, except Desert Storm, which doesn't really count. More of a live fire exercise.

I did check the pulley set screws. They are fine. I guess I'll just wait and see what happens. The warantee says good for five years, but you know how those work. Like insurance, they try hard to find a way not to pay.


Why are you otis of cologne?

Longhorn Dave.

 

[treedoctor]

Longhorn Dave,
I also have the Jet 1220. Had it for about 10 mos. Only use it about every third weekend. So it doesn't have a lot of hours on it so far. It has started making a clicking noise. Same spot on every revolution. Its in another town where I go on the weekend, so I can't check it out until later to see if some of the suggestion above help. I described the problem below in a thread titled
Lathe Clicking Noise. There were some good suggestions there, as well.
Let me know what you find out.

 

[Odie]

I know how you feel about the men you served with. I feel the same way, though it has only been 4 years since I retired and I didn't go to a war, except Desert Storm, which doesn't really count. More of a live fire exercise.

I did check the pulley set screws. They are fine. I guess I'll just wait and see what happens. The warantee says good for five years, but you know how those work. Like insurance, they try hard to find a way not to pay.


Why are you otis of cologne?

Longhorn Dave.

Longhorn Dave.....

I wouldn't sell yourself short on Desert Storm. If the Iraqis had decided to stand their ground and fight it out, things could have been bad......we didn't know what to expect, and you have my respect for being there when your country needed you. It counts!

otis of cologne is a favorite dog of mine. I started signing that way, and kind of liked it......so it stuck!

Take care......

otis of cologne

 

[Bill Boehme]

What does it sound like when they start to go? My Jet 1220 makes a rumbling sound that goes away only if I set the belt really loose. If it is bearings, do I need to stop immediately, or just keep going till they die, and replace? Any thoughts? Thanks in advance.

The very earliest sound is a slight ticking that you might not be able to hear unless your shop is very quiet and there is no other sounds going on and you have very good hearing. From there, it depends a lot on the type of failure mode that the bearings are going through. It could be a lot of loud ticking, swishing sounds, low rumbles, etc. Of course, by that time, it is no longer an early sign of bearing failure -- they are well past the point of having died and gone to bearing heaven.

 

[Longhorn Dave]

I checked out that thread. Good tips, but none that seemed to fit my situation. I'll assume its bearings beginning to go, and hopefully, I can handle the replacement. Thanks for all the input.

 

[KEW]

I would think if your bearings were very far gone, They would make a racket whether you had much belt pressure on them or not. Spinning the shaft should make noises.
Based on my experiences with a Delta Midi, I started out pushing the motor down when I tightened the locking lever, I could get some pretty serious noise out of the machine.
I then noticed experienced turners who turned small stuff on their mini and didn't even engage the locking lever (a time savings). Check to see if the weight of the motor is enough belt tension to successfully drive the spindle. I may add a little of the weight of my hand. I'm not sure - it is second nature to me now. Try reducing the tension and see if it slips on you (make sure it is not a spur drive spinning on the wood). If you can avoid the noise and still have sufficient belt tension to drive the spindle. Keep it there. If it is a bearing wearing out, It'll start making the noise at any tension soon enough.