View Full Version : varispeed belt making noise

04-08-2010, 01:13 AM
I picked up a varispeed drill press today that sat untouched in a warehouse for about ten years. It works OK but the varispeed unit is pretty noisy. Not only that, but the belt looks, well, loose. Until now I'd always avoided those cone pulley variable speed mechanisms because I've heard such horror stories about what happens when they wear out. This one can't be worn out because the machine was barely used ever since it was bought new in 1996. Is it possible for those belts to take a set? Might just letting it run for an hour or so help?



Forrest Addy
04-08-2010, 01:59 AM
Rub bar soap on the edge of the belt. Takes the squeak right out of it.

Richard Wilson
04-08-2010, 06:16 AM
I've got a varispeed unit on a Raglan (UK) lathe, and i assume that yours will be similar. There should be thrust races on either side to push the pullies together. Clean and lubricate these, and when you reassemble, make sure there is no slack, those thrust races need to be under load at all times, even at the extreme ends of their travel, otherwise they will rattle. Yes, a belt can take a 'set' when its been unused for some time. I would be tempted to treat it to a new one if you are going to strip it down. If the belt itself is slack, that suggests that the thrust races are not fully loaded, so I'm not surprised its noisy. Its worth taking some time to get a varispeed system set up properly.


04-08-2010, 06:21 AM
There are varispeed rebuild kits for bridgeports on ebay and all over the net.. Not sure about drill presses... At the very least you could look at the kits that are sold to see what kinda components are considered consumable.

Vaugely, I recall mention about bushings that wear out and need to be peroidicly replaced or noise is a result when this topic has come up before.

04-08-2010, 07:04 AM
If its been sat unused that long, then the belt has probably taken a 'set' around the two pulleys.

04-08-2010, 07:56 AM
If it is a Clausing, they still support them and offer a good (if expensive) selection of parts. Belts are often available at MSC or McMaster if you can identify it.

04-08-2010, 08:08 AM
It's an Alzmetall drill press. No manual. Alzmetall is still in business, but their parts prices are very expensive.

I'll take a better look at it and try a couple of things.


04-08-2010, 08:26 AM
Metalmagpie, does this drill press have a back gear in it. If so it probably has a timing belt that runs the back gear. My Tree mill had a very loud squeak to it even when just turning the spindle by hand. I thought the varispeed belt was the cause but when I started taking it apart and got the varispeed belt out, the noise was still there. It was the timing belt and I had never heard a timing belt make that kind of noise before. I ordered up a new one and now it's very quiet. If it doesn't have a back gear, disregard this message.

04-08-2010, 08:36 AM
Belts that have been installed and unused will take a set as mentioned, also get hard, if it is easily removed, try soaking it in brake fluid, this will soften up the rubber, or it could be wiped on with belt installed. Watch out for paint, brake fluid can cause peeling on a lot of it, and painful as all get out if it gets in the eyes.


04-08-2010, 09:38 AM
If you determine that the pulleys are working correctly (they may need some lube on the shafts to slide freely) you can heat the belt with a heat gun or propane torch while it's running. That will soften the belt temporarily and get the set out of it.

04-08-2010, 10:04 AM
Rub bar soap on the edge of the belt. Takes the squeak right out of it.

+1 I have to do this regularly with my 14" Rockwell lathe. Seems to need it less than it used to though. The light scent of Irish Spring is a nice change from dark cutting oil. :D

04-08-2010, 10:10 AM
Reeves (varispeed) drives are loud in general (I have 3 :) ), but do yourself a favor and get a new belt. If that belt has been sitting around for years, it's going to be really stiff.

If you're lucky, the industry-standard vari-speed belt number will be stamped on the spine of the belt. If it's not, you can measure the circumference, then measure the sheave angle.

04-08-2010, 02:28 PM
I ran the machine for awhile yesterday and then shut it off for the night. Today it is behaving much better. I think a lot of the belt "set" problem has resolved itself. Also, the belt now appears much tighter, so it seems to have found its sweet spot.

Still squeaking, though. I'll try bar soap and post the results.


04-08-2010, 03:56 PM
A couple of thoughts:

Variable speed belts don't appear all that tight when in use anyway....at least not like a standard v-belt.

The design is such that speed changes are really supposed to be made while everything is moving. If you made an adjustment while it was not running, then you would likely see a lot of slack as rotation is needed to allow the springs that hold the variable-gap sheaves to squeeze back to minimal size.

As Robert mentioned, the belts do seem to be prone to getting "hard"...but then again, they are pretty rigid even when brand new.

As you already noted, they do go egg shaped....especially if you were at one end of a speed range (such that one of the sheaves was large and one comparatively very small in diameter).


04-08-2010, 08:06 PM
Earlier today I did the soap trick. That really helped! Now it's quiet at any speed, but it still judders just a little while I'm actually changing speed.

I know about varispeed belts and didn't touch the speed changer while off. This machine was being sold -- maybe some lookylou tweezled it.

Anyway, now it's working fine. Thanks!