Squealing variable speed belt drive drill press

The title says it all. My old Clausing drill press uses variable pitch pulleys for speed adjustment. If the garage is under 90 degrees, the thing squeals like crazy. I've tried cleaning everything spotless, various belt dressings, bees wax and paraffin. Nothing helps long term. What's the secret to shutting this thing up? I know lots of other variable speed pulley systems are quiet.

Conrad Hoffman,

I have some thoughts. I don't know what type of variable speed drive your drill press uses. I have had experience with Gerbing Roto-Cone sheaves. These need to be cycled frequently to prevent fretting and general arthritis which prevents the belt from tightening sufficiently.

Vari-drive belts rely on a 'raw edge' to transmit power. This edge is very easily glazed and rendered useless if slipping is allowed to continue for any length of time. A inspection of this driving edge doesn't always indicate a problem...the ability to grip and transmit power is subtle.

If both sheaves move freely and allow the belt to tension properly, I would suggest you replace the belt. Clean all the belt dressings etc off the sheaves....they must be spotless.

Stuart

Rub a little bar soap in the edges of the belt. You know, bath soap furishhed in a bar.

In my shop on a shelf by the drill press have a bar on an old covered Arbuckle coffee can (the kind you opened with the key). I remember the soap when I was a boy. used it on the table saw belts and the fan bel of the old 31 Chevy. It's white and I'm almost certain it's Ivory. Needless to say it's an heirloom from Grabndpa George Addy to my Uncle Lyle to my Dad to me.. My nephew wants it and I won't let him have it yet. I might have a squeaky belt. You never know. Silly, isn't it?

Any way, that's how this family has fixed squeaky belts since 1922 or so.

Hmmmm! After rereading the original post, I see he is concerned with a drive belt that makes noise, not a belt that slips! If the price was right, I would still try a new belt.

Stuart

Conrad
Are you sure its the right drive belt?

Generally these are cogged, bit like a toothed belt, which helps stop squealing by damping out resonance as well as making it easier for the belt to ride up and down the pulleys. Get one with the wrong combination of cog size and stiffness and it will resonate and scream at you. As yours stops squealing at high temperatures, when the belt is more pliable, it could well have been fitted with one that's effectively too stiff. Could be due to cog dimensions or to actual bend stiffness. These things are more complex that they seem at first sight. Naturally wear changes the belt characteristics too.

I assume that the sliding pulley sheaves are all in good order the, that the spring tension is right with the shafts both straight and parallel. Look at the wear marks, if any, and see if they are concentric on all sheaves. Slight eccentricity due to sliding bush wear or poor fitting of bushes will often set the squeal off but usually the noise due to eccentricity tends to be speed related in that its noisy at some speeds but not others.

I agree with Stuart that its time to try a new correct belt. If you still have the problem then get the microscope out.

Clive

Do not put anything on your NEW BELT.

I think a new belt was tried many years ago, providing only temporary relief. I haven't checked recently, but the belt was crazy expensive last I knew, so I'm reluctant to change it. Mechanically, I think the pulleys are working ok, though they might need cleaning. It's a stick-slip sort of problem because even if you turn it slowly by hand, the belt will make noise. Slipping is no problem, so I'll try the bar soap. Nothing to lose as it comes off with water ;-)