pulley ratio formula

15 years ago

I remember only that it's not rocket science - but I can't remember exactly what the proceedure is - "senior moment", I guess.

How _do_ I figure speed reduction offered by different sized pulleys..?

_ThanX_ in advance..!

Sort by:Oldest

Comments (12)

lonewoof
15 years ago
Drive pulley diameter / driven pulley diameter * input RPM = OUTPUT RPM
digginlight
Original Author
15 years ago
Just the diameters, eh.? - not the circumferences. Well that makes the figuring lots easier.

ThanX
Related Professionals
Essex Landscape Architects & Landscape Designers · Kapaa Landscape Architects & Landscape Designers · El Segundo Landscape Contractors · Hannibal Landscape Contractors · Matteson Landscape Contractors · Nashua Landscape Contractors · North Chicago Landscape Contractors · North Highlands Landscape Contractors · Panama City Beach Landscape Contractors · Parkland Landscape Contractors · Plantation Landscape Contractors · View Park-Windsor Hills Landscape Contractors · Merrifield Landscape Contractors · Cary Decks, Patios & Outdoor Enclosures · Scotts Valley Decks, Patios & Outdoor Enclosures
bill_kapaun
15 years ago
Circumference is a direct ratio to diameter, so either will work. C=D*PI.
digginlight
Original Author
15 years ago
Does lonewoof's short little formula above imply the diameter at the outside of the belt.? the inside..? the middle of the belt..?

Or does it make no difference..?

ThanX again.
weed_cutter
15 years ago
As long as your measurments of the pulleys are consistent it makes no difference (measure both outside diameters).
hillbilly_2009
15 years ago
how do i find the ratios of multipule pulleys for example a 24in pulley driving a 12in pulley that is driving a 2in pulley
rdaystrom
15 years ago
Look up rpm calculators online such as the one on the link below and plug in the values and hit calculate.

Here is a link that might be useful: rpm calculator
Pooh Bear
15 years ago
Does lonewoof's short little formula above imply the diameter at the outside of the belt.? the inside..? the middle of the belt..? Or does it make no difference..?

Actually it refers to the diametrical pitch of the pulleys.
Diametrical pitch is usually a term used in gear measurements. But the same principles are also applied to pulleys. The measurement is where the center of the belt contacts both sides of the V on the pulley. Also known as the pitch diameter of the pulley.

Pooh Bear

Here is a link that might be useful: Diametrical Pitch - Wikipedia
mgfranz
13 years ago
I have packaged the RPM/Pulley Calculator into a desktop application if anyone is interested.

Here is a link that might be useful: Download RPM Calculator
stone_mike64_yahoo_com
13 years ago
A little off subject, but I was raised in a self sufficient heavy equipment shop, then went on to 35-40 years of welding and pipefitting and there are very few mathematical calculations I can't make! I hope to make your posters aware of the non-education your kids are getting in American schools that are dominated by the 'progressive' Department of Education, get informed ,the only thing your kids are being taught is 'progressive ideology', get involved to stop the ideologically 'dumbing down' of our kids!

Here is a link that might be useful: http://www.bing.com
BillSPhD
12 years ago
I've been teaching math, physics, and computer science at the University for 20+years. The percentage of students earning Top grades vs failing grades has not changed since our current methods of teaching has come into being. Don't listen to those who say we're loosing our younger generation: they are just as sharp and driven as we were at their age.
bill_kapaun
12 years ago
% of students earning top grades is the same.
% deserving top grades????????