• We invite you to join UKWorkshop.
    Members can turn off viewing Ads!

Bandsaw Screeching

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

Steliz

Camberwell Carrot
Joined
11 Dec 2017
Messages
412
Reaction score
49
Location
Hungary
I suspect this might be a bearings problem but if I can get input from the community before I get started that would be great.
I have an extremely loud screeching noise that seems to be coming from the area of the lower wheel axle. It only occurs on slow down after I've switched it off, not when it's running. Is this a symptom of worn bearings?
 

marcros

Established Member
Joined
11 Feb 2011
Messages
11,166
Reaction score
664
Location
Leeds
What bandsaw is it? Is it braked?
Is it new to you or has it always done it.
 

Yojevol

Clocking on
Joined
29 Jan 2017
Messages
706
Reaction score
159
Location
Cheltenham
It's probably the drive belt slipping as the brake is applied. Try increasing the belt tension.
 

Pete Maddex

Established Member
Joined
22 Apr 2005
Messages
9,172
Reaction score
124
Location
Nottingham
My Startrite has a brass bristle brush that rubs on the bottom wheel, it makes a screeching noise if it isn't adjused corectly.

Pete
 

Steliz

Camberwell Carrot
Joined
11 Dec 2017
Messages
412
Reaction score
49
Location
Hungary
It is a Record Power BS500.
I've tried putting more tension on the belt but that doesn't seem to be the problem. If I turn the wheels manually I can see the belt isn't slipping but the screeching is still there, just not when it's running under power.
The noise is so loud that I'm not sure if it's coming from the wheel axle or the motor drive wheel.
 

sunnybob

wysiwyg
Joined
11 Oct 2014
Messages
8,399
Reaction score
162
Location
cyprus
Slacken the pulley all the way out. Slacken the blade right off. Spin the wheel. if it screeches its the bearing.
If the wheel doesnt screech, put the pulley belt back. If it does then, its the motor. If it doesnt, put the blade back. If that screeches, its the bearing guides.
 

Steliz

Camberwell Carrot
Joined
11 Dec 2017
Messages
412
Reaction score
49
Location
Hungary
Ok, thanks sunnybob. It's definitely the bearings then.
Are bearings made to a set of standard sizes? As I'm not in the UK I will have to try and source them locally. I tried to find a new pulley belt for my P/T here without success and eventually I had to order it from Record for the princely sum of £44!
 

sunnybob

wysiwyg
Joined
11 Oct 2014
Messages
8,399
Reaction score
162
Location
cyprus
If you have a parts list for the machine it might list the bearing size. Its just diameter x width in mm. If not, just knock one out and read it off the side or measure it with a vernier or even take the old one to the shop and they will measure it.

Any automotive parts shop will have them, they are pretty cheap. Ask for Japanese, NOT chinese! The price is maybe 10% more, the quality is a 100% more. Here, the good ones are only a fiver each.

Make sure you clean the hole very well before pressing the bearing back in. Dont hammer the bearing in if poss. Use a large block of wood and try to press them in as if you are squeezing it in a vice. Keep the bearing dead level. If it cants sideways it will jam and then youre either going to damage the bearing or the housing. If you have to resort to a hammer, use the block of wood on the bearing and the hammer on the wood.
 

Steliz

Camberwell Carrot
Joined
11 Dec 2017
Messages
412
Reaction score
49
Location
Hungary
Apologies, on further investigation I removed the belt completely and tested it and the noise is coming from the motor pulley not the wheel axle. What does that mean in terms of fixing it?
 

sunnybob

wysiwyg
Joined
11 Oct 2014
Messages
8,399
Reaction score
162
Location
cyprus
from the motor itself? or a separate pulley?

If its from the motor itself, remove the fan cover and see if its rattling / rubbing anywhere. If its the motor, then you need either a warranty call, or to take it to a motor rewind shop.
Its almost certainly the motor bearings (same rules apply as for all bearings) but to get to them on an electric motor means removing and reassembling stuff that an amateur can easily destroy by mishandling.
 

Steliz

Camberwell Carrot
Joined
11 Dec 2017
Messages
412
Reaction score
49
Location
Hungary
The motor has a pulley wheel on the drive shaft. The fan looks fine but there is a 5mm rotational play in the drive axis.
I've never tried to fix a motor myself so, I'll look for a rewind shop, thanks.
 

Steliz

Camberwell Carrot
Joined
11 Dec 2017
Messages
412
Reaction score
49
Location
Hungary
OK, I have dismantled the motor and discovered that the noise is coming from the motor brake. This is a metal disc that is pushed against the motor housing by a spring.

imgonline-com-ua-CompressToSize-EvbqcvD4k9xDeL.jpg

imgonline-com-ua-CompressToSize-twF7DIyKtvH.jpg


Can this be cleaned to resolve the problem or does a part need replacing?

The bearing in the picture has a tiny bit of wiggle on it and I would just change it while I have access but I don't have a bearing puller. I don't think there is another bearing hiding behind the brake mechanism. Another concern is that the shaft will rotate freely about 5mm before hitting any resistance, is that 'normal'?
 

Attachments

Myfordman

AKA 9Fingers
Joined
19 Jan 2013
Messages
2,337
Reaction score
135
Location
Southampton area
I wonder if the brake disc is loose on the shaft and causing the 5mm you observe. It might simply be a grubscrew needing tightening. Fluttering of the disc could well be the source of the screeching too.
If you are in a one man amateur shop then I'd remove the brake altogether but that has to be your decision.
 
Top