PULLEYS OR SHEAVES?

I don't think you are thinking correctly about this. When you want to design a belt drive system, you start with the tables in Machinery's Handbook, the horsepower of the engine driving it, and the desired torque, and you look up the max. horsepower you can transmit with your pulleys, and then you depend on the pulley manufacturer to design their pulley to transmit that amount of torque. There isn't anything at all wrong with aluminum pulleys. All Bridgeport J-heads use aluminum pulleys, for example.

Most pulleys you buy these days are cast not from aluminum, but from pot metal (zinc). Further, they aren't machined after casting. And even the US-made ones have tons of runout, both radially and axially.

I recommend you learn to turn pulleys on a lathe. When you turn a pulley on a lathe, you get very little runout. The turning part isn't too hard. It's the keyway part that puts most people off. I did one recently and found it to be straightforward. I used the method of stroking a boring bar back and forth on the ways, with lots of oil, advancing maybe .003" between full-width passes. It worked fine for me on aluminum, but it would have been tougher on steel. I used an import boring bar made in India, designed to hold 3/16" toolbits either 90° or 45°. I bought it from Enco for about five bucks. I found it to be well made and just ideal for this job. I held it in an Aloris AXA-2 toolholder and advanced the bar sideways with the cross-slide. I measured the vertical location of the toolbit with a depth mic down from the OD of the part, which I knew accurately. Mine works just fine. I didn't invent this method, I simply did what others have done.

The other approach is to find a machinery dealer who's been in business a long time, maybe a woodworking house, and go talk to the guys in the back. Sometimes they will have a few drawers full of pulleys, old cast iron ones, that you can use.

Grant

snipped-for-privacy@n> I am wanting some small pulleys for v-belts. I need an assortment of

Thanks, Grant.

Your crystal ball is off-frequency. I have already been to the tables and know what I need.

What my post requested was an outlet for pulleys.

However, the other comments are appreciated, too.

I bought a few die-cast pulleys from WTT and thought they were some sort of poor aluminum alloy as the were pitifully weak.

I like the idea of the boring bar/key way deal.

On Thu, 24 Jun 2004 19:16:28 -0700, Grant Erwin wrote:

Quoted: I don't think you are thinking correctly about this. When you want to Quoted: design a belt drive system, you start with the tables in Machinery's Quoted: Handbook, the horsepower of the engine driving it, and the desired Quoted: torque, and you look up the max. horsepower you can transmit with Quoted: your pulleys, and then you depend on the pulley manufacturer to design Quoted: their pulley to transmit that amount of torque. There isn't anything Quoted: at all wrong with aluminum pulleys. All Bridgeport J-heads use aluminum Quoted: pulleys, for example. Quoted: Quoted: Most pulleys you buy these days are cast not from aluminum, but from Quoted: pot metal (zinc). Further, they aren't machined after casting. And Quoted: even the US-made ones have tons of runout, both radially and axially. Quoted: Quoted: I recommend you learn to turn pulleys on a lathe. When you turn a pulley Quoted: on a lathe, you get very little runout. The turning part isn't too hard. Quoted: It's the keyway part that puts most people off. I did one recently and Quoted: found it to be straightforward. I used the method of stroking a boring Quoted: bar back and forth on the ways, with lots of oil, advancing maybe .003" Quoted: between full-width passes. It worked fine for me on aluminum, but it Quoted: would have been tougher on steel. I used an import boring bar made in Quoted: India, designed to hold 3/16" toolbits either 90° or 45°. I bought it Quoted: from Enco for about five bucks. I found it to be well made and just Quoted: ideal for this job. I held it in an Aloris AXA-2 toolholder and advanced Quoted: the bar sideways with the cross-slide. I measured the vertical location Quoted: of the toolbit with a depth mic down from the OD of the part, which I Quoted: knew accurately. Mine works just fine. I didn't invent this method, I Quoted: simply did what others have done. Quoted: Quoted: The other approach is to find a machinery dealer who's been in business Quoted: a long time, maybe a woodworking house, and go talk to the guys in the Quoted: back. Sometimes they will have a few drawers full of pulleys, old cast Quoted: iron ones, that you can use. Quoted: Quoted: Grant Quoted: Quoted: snipped-for-privacy@nopenotachance.com wrote: Quoted: > I am wanting some small pulleys for v-belts. I need an assortment of Quoted: > small diameters with 7/8" keyed bore. The diameters for the belt Quoted: > should be around 2 to 6 inches and should not be aluminum due to Quoted: > driving torque. Quoted: > Quoted: > I can find them in Grainger's, MSC and WTT. Whew! They want real Quoted: > money for them and WTT doesn't have a good assortment of anything but Quoted: > aluminum. Quoted: > Quoted: > Is there a Pulleys R US around? Quoted: > Quoted: > What about machining some? Don't want to cast metal, however. Not Quoted: > yet, anyway.

Look in the yellow pages under "bearings" or "power transmission" -- any small city will have several listings. Motion Industries and Kaman are two large national ditributors, and there are likely to be smaller regional companies as well. These places can hook you up with good quality steel and cast iron pulleys.

I'd suggest looking at taper-lock or QD bushed pulleys if you want to avoid boring the pulleys yourself. They're also easier to install/replace and when made up properly give an interference fit on the shaft.

As far as prices go, I just checked my price from Motion Industries on a Browning BK50H. Grainger gets $23.74, MI is $13.48 for the Gates equivalent.

Ned Simmons

Ive got about 5000 lbs of pulleys, bushings etc. Come on over and take your pick. You will however be pallet box diving. Wear your working clothes.

Gunner

That rifle hanging on the wall of the working-class flat or labourer's cottage is the symbol of democracy. It is our job to see that it stays there. - George Orwell

Choices, choices. Have you considered Poly-V belts? The pulleys are faster to make on a lathe than the ordinary V.

I get most of my pulleys at flea markets and salvage places. The taper-lock types that were mentioned are easy to mount (usually) without requiring a keyway.

Some have mentioned that they get used serpentine pulleys at auto junkyards.

WB .............

Dad makes all of the one-off pulleys we use around the shop. We have made them in limited production for customer machines as well, it allows us the use of non-standard size combinations.

He roughs the groove in with a parting tool, then finishes with a tool steel form tool, works well in mild steel.

Have a look at

While there is only a couple of hours on this, it shows no sign of wear. The belts don't heat up. BTW, it's a 50hp engine.

Ted

Thanks all, for the good information about pulleys. Many good suggestions will be followed.

Quoted: I am wanting some small pulleys for v-belts. I need an assortment of Quoted: small diameters with 7/8" keyed bore. The diameters for the belt Quoted: should be around 2 to 6 inches and should not be aluminum due to Quoted: driving torque. Quoted: Quoted: I can find them in Grainger's, MSC and WTT. Whew! They want real Quoted: money for them and WTT doesn't have a good assortment of anything but Quoted: aluminum. Quoted: Quoted: Is there a Pulleys R US around? Quoted: Quoted: What about machining some? Don't want to cast metal, however. Not Quoted: yet, anyway. Quoted: Quoted: Thank you. Quoted: Quoted: