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Pulleys source

W

Wayne Spence

Joined
Jun 13, 2009
Messages
217
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Location
Denver, Colorado
Know of a source for pulleys? I am thinking of the machined steel ones that are well balanced, if pocketbook tolerated. I tried a search but came up short.
 
pulleys aka sheaves

i think the term you are looking for is "sheaves" or "motor sheaves"
type that in and see what comes up
I know from past experience that machined sheaves are quite expenisve but well worth the money given they are better balanced.
One place to search are companies that sell v belts. or fan belts.
Not sure what your purpose is but if it is for retrofitting a bandsaw try calling Iturra design in jacksonville florida
 
McMaster-Carr is what came to mind for me. I presume that you are thinking about the type that is machined cast iron and requires a separate hub to match it to the spindle size. They are not cheap. I would like to suggest using using machined aluminum pulleys designed for J-section belts rather than the standard ABCD V belts. The efficiency of J-section belts is much greater and they are becoming much more commonplace on machine tools.
 
Bill Boehme said:
McMaster-Carr is what came to mind for me. I presume that you are thinking about the type that is machined cast iron and requires a separate hub to match it to the spindle size. They are not cheap. I would like to suggest using using machined aluminum pulleys designed for J-section belts rather than the standard ABCD V belts. The efficiency of J-section belts is much greater and they are becoming much more commonplace on machine tools.
Click to expand...

Just a note of agreement on the J-section belt. The reason they are so efficient at transmitting power, is the contact surface area is greater, and does not rely on "wedging" that area of contact......the surface is directly opposed.

I have the J-section belt installed with aluminum step pulleys on my Woodfast lathe. It is superior to the V-belt.

ooc
 
Actually, Odie, they do wedge just like any other v-belt. When any v-belt reaches the point where the top of the rib(s) is contacting the bottom of the grove in the pulley, they lose traction and should be considered to be worn out. The surface area that is gripping the sidewalls in a J-section belt is approximately the same as traditional belts so torque transmission capability is about the same. The big difference in efficiency is mainly the result of the difference in thickness. In the traditional single V belt, a lot of power is wasted in wrapping and unwrapping the thick belts and in the work needed to drive the belt into the deep wedge and then pull it back out. Supposedly some of this energy is recovered because the belt acts like a spring storing kinetic energy, but in practice, it is more like a weak spring with a large viscous damper attached to it. Much of the recovered energy just goes into the viscous damper (both the spring and damper are simply characteristics of the rubber) to become heat. Conversely, the low cross-section J belts lose far less energy in this process.

There are also flat belts which are the most efficient of all, but you really don't want to consider anything like that unless running eqauipment that is delivering hundreds of horsepower. The flat belts are quirky just like the sandpaper belt on a belt sander which requires a slightly crowned drive wheel and the ability to slightly tilt one of the hubs so that the belt will continue to track properly.
 
Are we singing from the same hymnal? Or is "just like any other v-belt" an imperfect comparison?

Your J-section seems to be a subset of V-ribbed belts, H through M, according to Machinery's Handbook, 24th Edition, p. 2310, which states "V-ribbed belts do not have the wedging action of a V-belt and thus operate at higher tensions." At such small dimensions (J ribs ~0.16" total x 0.092"), it's difficult to distinguish the behavior, but if the ribs bottom out in the grooves, the spine is probably shot as well.

Otherwise, bingo.
 
Joe Greiner said:
Are we singing from the same hymnal? Or is "just like any other v-belt" an imperfect comparison?

Your J-section seems to be a subset of V-ribbed belts, H through M, according to Machinery's Handbook, 24th Edition, p. 2310, which states "V-ribbed belts do not have the wedging action of a V-belt and thus operate at higher tensions." At such small dimensions (J ribs ~0.16" total x 0.092"), it's difficult to distinguish the behavior, but if the ribs bottom out in the grooves, the spine is probably shot as well.

Otherwise, bingo.
Click to expand...


Yes, you are right, Joe. I should have been clearer about what "other" belts I was talking about. I knew about the other sizes, but figured that TMI at this point would just muddy the waters of what I was trying to convey -- that plus it was past my bedtime and I was in a hurry to shut my computer down. If I am not mistaken the big long belt used in automobiles is an M-section. I am not sure about the size of the tiny one used in the Jet mini lathe or those in sewing machines. I just had one break in the power head of my vacuum cleaner and am searching for a replacement on the web that is cheaper than the ridiculous price that the manufacturer charges.
 
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