Noisy Band Saw Bearings

dusty · Post by **dusty** » Thu Sep 20, 2012 10:06 am

[quote="JPG40504"]Are you causing the blade to track in/out of the space between the dual bearing?

I have heard similar noises but do not recall if recently(my bandsaw is currently unavailable or I woiuld check).

Food for thought: The back of the blade is essentially flat(unless excessive honing has occurred) and the space between the bearings is convex shaped on each bearings. That makes the back corners of the blade ride on the rounded sides of the bearings. This is not a stable condition, and the blade will tend to slide sideways on the curved bearing surfaces and may even oscillate.]

You ask, am I causing the the blade to track in and out of the space between the bearings? Something is causing it but I am doing nothing during this video to cause that to happen. That is the way the blade reacts to a slightly maladjusted Auto-Track bearing.

I see and understand your point. I have even given some thought to using a spacer between the bearings to provide a very narrow grove that the blade would ride in. I just don't have an appropriate spacer. I think the Carter bearing is grooved.

However, very careful alignment of the Auto-Track bearing (to the blade) does eliminate what you see in the video. It also eliminates the noise variation that you can hear when the blade moves in and out of the track between the two bearings.

In the video you can hear a noise that I have determined is the auto-track bearing as it rotates. If I stop the bearing with pressure applied to the outer race, the noise stops. I suspect that new bearings would sound different (though that silence may be short lived).

I have done what I can do until my new blade arrives and then I'll sorta start all over. I have three topics in the works 1) noisy bearings, 2) rough cut and 3) bandsaw drift.

I'll attempt to close they all at the same time.

Until then, I am hoping that several will comment on the noise level in the video as it compares to their own machines.

fixit · Post by **fixit** » Thu Sep 20, 2012 12:01 pm

Dusty,

After watching your video it is easy to tell why your band saw makes so much noise! You don't USE IT enough!:D:D:D

I can't keep mine that clean (I don't think it was that clean out of the box now that I think about it) no matter what I do.

Just kidding - but then your shop shows you're a meticulous housekeeper so I shouldn't be surprised at what's shown on the video.

dusty · Post by **dusty** » Thu Sep 20, 2012 12:44 pm

I revised the original bearing test setup to get rid of the vise. It was too clumsy and did not hold the bearings real securely.

Beside, the new setup is just so much more logical. I think the video will tell all.

Using this setup, I retested all of the bearings that I have and was unable to identify the ones that I thought were noisy yesterday. What I need now is a stethoscope to replace the screw driver to my ear.

Ed in Tampa · Post by **Ed in Tampa** » Thu Sep 20, 2012 2:32 pm

dusty wrote:I revised the original bearing test setup to get rid of the vise. It was too clumsy and did not hold the bearings real securely.

Beside, the new setup is just so much more logical. I think the video will tell all.

Using this setup, I retested all of the bearings that I have and was unable to identify the ones that I thought were noisy yesterday. What I need now is a stethoscope to replace the screw driver to my ear.

Dusty
I assume you showing us the bearings themselves make no noise? I agree the noise is the blade rub on the bearing.

I love your test set up. I would run it until the bearing started to get warm. Then I would drop the warm/hot bearing in a pan of Marvel Mystery Oil or grahphite oil and let the bearing as it is cooling down draw some oil into it.

I know its a sealed bearing but I have done this many times with motorcycle sealed bearings and they all managed to draw in the oil through their "seals".

PS I had an account that manufactured bearings. They would test their bearings by putting the balls from the bearing in a confined area covered in a test oil and lower a spinning ram into them so they spun. The ram was cone shaped so the more they lowered the ram the higher the pressure. The ram also had variable speeds. A bearing had to survive x pressure at x speed for so long. Each test concluded with the balls welded together.

One day they were out of test oil and a technician went and got a can of graphite oil. They put in the bearing balls filled the cup with graphite oil and began the test. To their amazement they could not cause a failure. The machine did not have enough speed or pressure to increase the friction so high that the balls failed. Needless to say this caused no small stir within the company, everyone was soon talking about it. I know shortly after they had reps from lube companies in plant and I believe they changed their lubicant immediately.

dusty · Post by **dusty** » Thu Sep 20, 2012 3:13 pm

Ed in Tampa wrote:Dusty
I assume you showing us the bearings themselves make no noise? I agree the noise is the blade rub on the bearing.

I love your test set up. I would run it until the bearing started to get warm. Then I would drop the warm/hot bearing in a pan of Marvel Mystery Oil or grahphite oil and let the bearing as it is cooling down draw some oil into it.

I know its a sealed bearing but I have done this many times with motorcycle sealed bearings and they all managed to draw in the oil through their "seals".

PS I had an account that manufactured bearings. They would test their bearings by putting the balls from the bearing in a confined area covered in a test oil and lower a spinning ram into them so they spun. The ram was cone shaped so the more they lowered the ram the higher the pressure. The ram also had variable speeds. A bearing had to survive x pressure at x speed for so long. Each test concluded with the balls welded together.

One day they were out of test oil and a technician went and got a can of graphite oil. They put in the bearing balls filled the cup with graphite oil and began the test. To their amazement they could not cause a failure. The machine did not have enough speed or pressure to increase the friction so high that the balls failed. Needless to say this caused no small stir within the company, everyone was soon talking about it. I know shortly after they had reps from lube companies in plant and I believe they changed their lubicant immediately.

I don't know how long it would take to develop a heating effect. In the real world, the only side loading is that produced by the blade and that is very little. You can test that by applying pressure to the back side of the blade while it is running. Be careful. You'll be surprised how little it takes to cause the blade to creep on the wheels.

I put enough pressure on it to more than exceed what the blade does and ran it for about 5 minutes. No detectible heating.

This is when I wish I had access to the environmental test labs that I used to work in. There we pushed items to their performance limits while exposing them to environmental extremes. Causing the parts to fail was what we were tasked to do.

greitz · Post by **greitz** » Thu Sep 20, 2012 4:01 pm

"Causing the parts to fail was what we were tasked to do."

Man, I surely missed my calling, 'cause I'm real good at causing things to fail!!!

Gary

dusty · Post by **dusty** » Thu Sep 20, 2012 5:35 pm

greitz wrote:"Causing the parts to fail was what we were tasked to do."

Man, I surely missed my calling, 'cause I'm real good at causing things to fail!!!

Gary

No, No, No

We didn't abuse them. We didn't break them. We stressed them to the point of detectible failure.

We did that so that we knew they would not fail when we put them up in orbit. The cost of house calls was most prohibitive.

billmayo · Post by **billmayo** » Thu Sep 20, 2012 6:25 pm

I found one of the shims/washers used with the older roller bushings worked well between the 2 bearings. I stoned the back edges of the bandsaw blade (45 deg) so that the blade rode well between the bearings but did not go into the groove or stick. If either bandsaw wheel rim is bent or warped, I had problems with tracking of the blade.

Stress testing can be great fun. I build many jigs and test setups that I played with for years using the Shopsmith equipment. I found most times, there were noises, indicators and heat telling me when I was approaching a failure. For a few years, I spent half my time testing various ideas, concepts and limits with Shopsmith equipment. I spent a lot of time determining how various bearings survived from 7,000 to 20,000 RPM with and without load so I knew which bearings I wanted to buy and use. Many times, a must cheaper bearing was better.

dusty · Post by **dusty** » Thu Sep 20, 2012 6:41 pm

billmayo wrote:I found one of the shims/washers used with the older roller bushings worked well between the 2 bearings. I stoned the back edges of the bandsaw blade (45 deg) so that the blade rode well between the bearings but did not go into the groove or stick. If either bandsaw wheel rim is bent or warped, I had problems with tracking of the blade.

Stress testing can be great fun. I build many jigs and test setups that I played with for years using the Shopsmith equipment. I found most times, there were noises, indicators and heat telling me when I was approaching a failure. For a few years, I spent half my time testing various ideas, concepts and limits with Shopsmith equipment. I spent a lot of time determining how various bearings survived from 7,000 to 20,000 RPM with and without load so I knew which bearings I wanted to buy and use. Many times, a must cheaper bearing was better.

Bill, I have some shims that have a larger ID than the bearings but a smaller OD. Can I get away with using those.

Wow, 45° on both back edges. That is almost enough to be called "sharp".

Is this what every one means when they say to hone the back edge? If so, I have not been doing that at all.

reible · Post by **reible** » Thu Sep 20, 2012 11:13 pm

dusty wrote:I still do not fully understand the noise emitting from my bandsaw but I do now believe I know what needs to be done to reduce some of it.

Simple alignment of the Auto_Track bearing to the blade. I say simple because it is very easy to do but it must be done meticulously. What looks to be close enough just might not be 'right on".

I think this video tells all with regard to the noise source. The procedure for installing and aligning the Auto-Track bearing is contained within the operators manual and need not be repeated here.

When I stop the auto-track bearings from turning, the noise level reduces even more. I believe the bearings that I have now could be better (quieter). These particulars bearings have been installed for about 1 year.

I should have done this video with the bandsaw mounted on the Mark V. Much of the background noise is inherent in the Power Station.

I am very interested in hearing a few comments about the bandsaw noise. Is what you hear in this video typical of your own set up or am I working on an anomalous source of noise.

I have just listen and watch the video. The way the blade is jumping around never happens on my saw.

The sound of it when in the proper location still sounds a bit noisy, do you have guide blocks installed? If so which ones?

Ed