Help me diagnose a "squealing" sound

billmayo · Post by **billmayo** » Tue May 26, 2009 9:35 pm

I would move the speed control to HIGH (motor does not need to operate to do this) and remove the motor drive belt from the motor sheaves. Do not let the floating sheave go when winding the drive belt off. With the motor belt disconnected, the motor sheaves should spin freely without any roughness or noise. The fan and floating sheaves should be fairly tight on the motor shaft. There is a spacer behind the fan sheave and in front of the motor bearing that can get crushed and cause the fan sheave to hit/rub the motor housing. I always use belt dressing (any auto parts place) on both belts several times a year to cut down on any belt noise. I often find the front motor bearing (next to the fan sheave) is going bad or has seized. Also I have found the fan sheave set screw loose that will let the fan sheave rock over time and touch the motor housing when operating. Finally you can turn the motor on and see if there is any noise.

tdubnik · Post by **tdubnik** » Wed May 27, 2009 4:42 am

Thanks for all of the suggestions. I'll be checking them out today and hopefully resolve the problem.

tdubnik · Post by **tdubnik** » Wed May 27, 2009 6:55 am

bucksaw wrote:The PolyV belt may need re-adjustment or may have a bearing that is dried out and needs replaced. If you have a stethoscope, try listening to difference parts of the headstock and see if you can isolate the sound. I doubt that it is the drive belt unless you made the belt a link too long and it is running a little loose (should be 35 links for the PowerTwist red belt). I'm guessing it's the small bearing on the idler shaft where the speed control attaches.

It seems that the Poly-V belt was a little loose and that I had 36 links in my link belt. I tightened the Poly-V and removed 1 link from the link belt. I've only run it for about 10 minutes but so far no unusual noises. Hopefully these fixes have taken care of the problem. Thanks for the advice.

While I had the link belt off, I checked for any roughness or resistance anywhere in the drivetrain. The motor ran smooth as silk and quiet. It turned freely and takes a while to spin down when the power was turned off. All of the shafts turn free with no noticable roughness or resistance. I can easily turn them all by hand just by turning the shaft with no sanding disk needed.

As far as I can tell my machine is in good shape and maybe the belt adjustments have taken care of the squeal. Once I get a little more time on the machine I'll provide an update.

Thanks to everyone for their suggestions.

JPG · Post by **JPG** » Wed May 27, 2009 1:30 pm

ED: What makes you so Smart!!!!!?:D At least you saw the obvious. Would have been nice to be able to hear it ourselves though. Squealing Bearings and rubbing parts sound different from slipping belts.

Hooray!!!!:) I think it is FIXED!!

tdubnik · Post by **tdubnik** » Sat May 30, 2009 4:52 pm

Thought I would post an update.

Since the belt fixes, I have done some serious jointing and the squeal is gone. I am in the process of building a "proper" workbench and have started getting the lumber for the top in shape. I spent a couple of hours face and edge jointing 3" wide by 78"long by 1"-2 1/2" thick hard maple. I started with rough lumber so this took a few passes. There were 22 boards in total. The SS performed flawlessly. It never complained and ran for over 2 hours straight.

Thanks again for all of the suggestions and the help in resolving my problem. This is an awesome board with very awesome members.

charlese · Post by **charlese** » Sat May 30, 2009 11:03 pm

Great news! Remember to clean and lubricate after 10 hours.