Help! Cant find a belt!

[888guitars]

Here is a pic of my winder. I cant seem to find a round belt to use for the motor. I just broke this one and have tried a lot of ways to glue it back together to no avail. Anyone have any ideas? The length is not too important as i can just move the motor. But 10 -11" would be perfect

[dave_b]

You might take it to an appliance parts place (e.g. Dey) and see if they can get close for a cheap price. Of course, if you have a place in town that services sewing machines, they should be able to hook you up.

[StarryNight]

not sure if you can find the width you need, but have you looked into those V-belts?

[Bruce Johnson]

The simple thing is to get a silicone rubber O-ring of the right size. They work very well as drive belts for small machines, and will last for decades. If you're not familiar with O-rings, these are round rubber rings that are used as seals in hydraulic fittings and devices. They're available at any local shop that repairs hydraulic equipment. They have lots of sizes in stock, plus they have rolls of the material, which they can cut to length and glue the ends together. The important thing is that you want the O-ring in silicone rubber, which is orange in color, or fluorosilicone, which is blue in color. The more common black O-rings, which are Buna-N material, won't last as a drive belt.

The size that you want will be about 1/4" (cross-sectional diameter) by 3 1/4" to 3 1/2" ID. That will come out to your 10"-11" length. The official AS568A Dash number size that you want is 415.

Here's the McMasters listing for that size in silicone; $7.24 for a pack of 5:
http://www.mcmaster.com/#o-rings/=adg744

[Joe Gwinn]

Here is a pic of my winder. I cant seem to find a round belt to use for the motor. I just broke this one and have tried a lot of ways to glue it back together to no avail. Anyone have any ideas? The length is not too important as i can just move the motor. But 10 -11" would be perfect

Round belts are standard. Here is one source: https://sdp-si.com/eStore/Direct.asp?GroupID=510. You will also need to buy the connectors: https://sdp-si.com/eStore/Direct.asp?GroupID=32.

My guess from the photo is that you need the 1/4 inch cross-section diameter belt, but it's hard to tell. Measure on the pulley, as the belt that came with the winder may or may not be correct. The belt should not quite fill the groove, which should be round in cross-section.

[Rick Turner]

That's a toothed timing belt, and what's weird is that it's working at a reduction so the turns on your counter is not the same as the turns of the actual bobbin. The drive pulley is smaller than the counter pulley.

It's a similar counter to the one on my CoWeCo coil winder which has to read 1:1.

I'd go with a timing belt, but you might want to just manually check to see how many turns of the winding lathe spindle equals how many turns on the counter. Unless there's an internal step up, your turns counts are likely to be off by a considerable amount.

[Bruce Johnson]

Rick;

He's talking about the (missing) belt going back to the motor, not the timing belt down to the counter. Nate, it is a little odd that your counter is being driven at a 1:2 (it appears) ratio. Is that intentional?

Joe, I prefer the silicone rubber O-rings to those urethane tubing belt kits. The silicone rubber has amazing traction around small pulleys, even at very low tension. And they have no connector to go thump-thump around the little motor pulley. I put a pair of them (3/16" x 12" ID) on my pantograph engraving machine, and they've been faithfully running for about ten years now.

[Rick Turner]

Got it, Bruce. Understood. Fully agreed re. the "O" ring. I'm going to set up a high speed spindle on my CNC machine and drive it with an "O ring" using one of the ISO 30 tool holders as the drive pulley. It should handle the speed...24,000 RPM on the drive and hopefully 48,000 RPM on the engraving spindle.

[Bruce Johnson]

Rick;

Yeah, the silicone O-rings should be fine for that speed, as long as you keep the center-to-center distance in close. A single 3/16" O-ring driving a 2" pulley is probably all of the torque you need for engraving. If not, make up some aluminum pulleys with multiple grooves and run a couple of O-rings in parallel. The silicone is stretchy enough that they'll share the load.

My engraving machine is an antique 1950's New Hermes, and only hits about 5000 rpm. The pulleys are about 2" diameter on 15" centers. Even at that length and speed, the O-rings stay on and drive just fine. By luck, I found a bunch of the right size O-rings in blue fluorosilicone at a surplus place when I was rebuilding the machine. I bought a dozen of them, but after ten years, I'm still on the first pair.

[David Schwab]

There are also those link belts you can make any length you want. They work real well in things like drill presses.

[Bruce Johnson]

Link belts are great for many types of applications, such as improving the drive torque of the import drill presses. I have them on 4 or 5 machines in my shop. On some other machines, I've tried them, and gone back to classic V-belts. It depends on the drive system.

What we're talking about here is a smaller size class. The silicone O-rings are optimal for drive systems with 1/8 HP or less, fairly high speeds, and a high reduction ratio (a small pulley on one side). Think sewing machines, engraving machines, and coil winders.

[Joe Gwinn]

Joe, I prefer the silicone rubber O-rings to those urethane tubing belt kits. The silicone rubber has amazing traction around small pulleys, even at very low tension. And they have no connector to go thump-thump around the little motor pulley.

But won't the connector thump build a beat into the music?