Bench grinder making noise.

[woodchucker]

I rebuilt this grinder about 6 months ago.
New bearings, new cap, cleaned it up. Put Timkens in... she's been running fine since.
I put new washers on the wheels, these are machined, not cast.

After it's been running a while it gets hot... not too bad, but it's making a noise. I can't figure out if I have a bearing issue, or electrical issue.
Again new Timken bearings... made in China... seems like many Timkens are now in China..
Please listen, tell me do you think I have an electrical issue (can't imagine what) do I have a bearing issue (not a normal bearing sound) it happens after its hot.
btw notice the water pot, not a ripple... ????
I just cooled it down, and got her back up... she was fine, until she reached 104 degrees, then started making noise again.
bearing?

 

[tq60]

Turn by hand, feel any dragging?

Is the start wiring on?

Make different noise when unplugged

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[woodchucker]

seems like I am going to have to get a mechanics stethoscope tomorrow.
I can't tell. I suspect a bearing, especially since its heat related. I don't think it's electrical, but not sure.

I took it apart, and can't tell. Can I get a young buck over hear to listen to it..

 

[woodchucker]

Turn by hand, feel any dragging?

Is the start wiring on?

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no
no, I did that when I rebuilt it... burned the cap out in 10 seconds.. let the smoke out..
I had not put the start weight sleeve in the right location and it left the start winding activated.

 

[ddillman]

I had a problem with my belt sander where the start switch was stuck in the start position. It caused the motor to get hot and didn't sound right.

 

[woodchucker]

Is 104 f hot? I can disconnect the cap.. start it by hand. right now I have it running w/out wheels to see if I can see.
I reassembled the end bells. the bearings feel good, but that doesn't mean much.. me feeling them vs 3450 rpm is quite different.

 

[woodchucker]

right now it's about 114 on the high end.
and it's making a noise, but not what we heard b4.
a slight pulsing. and as I am writting this, it's quieting down. in the morn when it cools down it just reached 120
I'll disconnect the start cap and see.
View attachment 391069

 

[woodchucker]

removed the capacitor, its over 120 degrees right now.. not making the same noise... I hear something, different.
need a stethescope. will venture out in a bit.

 

[BGHansen]

Would it make sense to get it up to speed and when it starts making noise unplug it? If it still makes noise as it starts slowing down it'd seem to be a bearing issue. If the noise goes away when you unplug it, probably an electrical issue. Good luck!

Bruce

 

[woodchucker]

well, I'm stuck. since I have reassembled it, it does not appear to be happening... I have no idea what was wrong. The stethoscope does not indicate a bearing problem. The temp has reached 130 degrees, so I'm a little bothered by that. I think if I keep running it, it will just keep climbing. That temp increase happens even w/out the start cap installed.

so it's resolved, but I don't know why.