Are link belts known to be noisy?

[como]

I have just replaced the bearings in my union jubilee lathe as I was starting to notice a slight wobble on the spindle.

I followed the instructions given by parvum in the thread https://www.ukworkshop.co.uk/forums/lathe-bearings-t43546.html

Anyway, the bearing change was successful and cured the wobble problem and it's now running pretty sweet,

However, I thought the new bearings may have made the lathe run a bit quieter, but the noise level seems to be the same as it was before the bearing change.

Which brings me to my question... I'm now looking for other ways to make the lathe run a little quieter and was wondering if the old link belt which is driving the lathe could be generating some noise.

I know that there is a right way and a wrong way to put on a link belt, and I have tried both ways with no noticable difference in noise level.

I've also ran the motor with the belt disconnected to check if the motor was noisy, but no the motor runs pretty quiet.

I would like ask for peoples opinions on whether you think a new v-belt would make the lathe run a little quieter?


Thanks in advance

 

[PeterBassett]

I think a v belt would be quieter. When you think about it each of those links has to make contact at speed with two pulleys. It's bound to make noise.

At least a v belt would be continuous.

Pete

 

[Paul.J]

I have a link belt on me tablesaw,and would say that it is quieter than the rubber V one that was on their. :?

 

[CHJ]

As a temporary trial have you got a length of thick cord or rope? try running it with this in place and see if it is quieter or if it's bearing noise being amplified/transmitted by the casting.

You can join the cord by sewing the ends together and should run long enough to get some feedback regarding belt/bearing noise.

Try lubricating your belt with a dry PTFE lubricant, should make little difference to drive capabilities but could well quieten any belt 'squeak'.


Is the belt vibrating along its unsupported length?

 

[como]

Thanks for taking the time to reply guys.

Chas, I have an old rachet strap that I could make a trial belt from, I will give it a go later. I am starting to think that it is the bearing noise being amplified as you mentioned. I suppose the trial belt will prove it one way or another. If I find that the trial belt does make a difference, I will then replace the link belt and try spraying it with some PTFE lube. As for the belt vibrating, there doesn't seem to be any vibration, just a small amount of flapping (possibly about 10mm). The belt is tensioned by the weight of the motor, then the motor is bolted tightly to the headstock/column.

Thanks for your help so far, I'll keep you posted.

 

[CHJ]

....... I am starting to think that it is the bearing noise being amplified as you mentioned. ......

If you think it's bearing noise you can check with a long screwdriver, handle to the ear, tip to housing area near the bearing location.

If it's the bearings generating the noise you can hear it should be louder and in sync.

Does the noise stay the same with and without all covers fitted?

 

[como]

ok, so I tried the temporary belt and it didn't make any difference to the noise level.

I've just had a go at listening to the bearings with a long screwdriver (which is a useful trick by the way, I must remember that one) and I noticed that the outboard bearings seem to be louder than the inboard bearings. The outboard bearings were a much tighter fit when I put them in, and needed to be tapped into place with a piece of wood, rather than a push fit as the inboard ones were. The old bearings were also tight on the outboard side as they were a bit of a pig to knock out.

Is it possible to have bearings fitted too tight?? And could this account for the noise???

 

[CHJ]

.....
Is it possible to have bearings fitted too tight?? And could this account for the noise???

It is virtually impossible to compress the outer race enough to make any difference to its tolerances, as long as you only hit or pressed the outer race and not the inner then it should be fine, one thing to check is that you have seated at the correct depth in its housing or that its fit on the shaft is not too tight or putting any side load on the race.

The headstock front bearing/shaft position/fit is normally considered as fixed, the rear headstock bearing should allow a small amount of longitudinal movement of the shaft when its length varies due to temperature changes.

 

[como]

Thanks for help Chas, the rear headstock bearing is a self aligning bearing which confirms what you were saying about compensating for longitudinal movement.

I suppose as the noise in no worse than what it was before I changed the bearings, I should just accept it as the lathes normal operating noise level. Unless there is anyway of damping the bearing noise which is resonating in the headstock column.

 

[CHJ]

..... the rear headstock bearing is a self aligning bearing which confirms what you were saying about compensating for longitudinal movement. .....

The self aligning selection is more to do with the possibility of the two headstock bores being a few thou. out of alignment when manufactured or due to subsequent casting movements as stresses release.
You may find that the noise reduces after a ru-in period
(or you just get used to it and it in effect 'goes away' :lol: )

 

[Dust Busker]

Have you thought of trying one of the plastic link belts that are sold by (among others) Chronos? They are quieter than the traditional Brammer type. I have used one on a Viceroy TD6 and it did make a difference.