pulleys and rpm's

[odorf]

need some math help

little project, with a 3450 rpm motor

and 1.5 drive pulley with a 6'' slave pulley

attached to a jack shaft, using pillow blocks

1.5 drive pulley with a 12'' slave

what is final rpm?

View attachment BasementBath.jpg

 

[odorf]

A 1.5 inch circle has a circumference of 2.36 inches.
A 6 inch circle has a circumference of 9.42 inches
A 12 inch circle has a circumference of 18.85 inches

So what I get is the first pulley is turning at 3450 rpm the ratio between the first and second pulley is 4 to 1 (9.42/2.36) so at the second pulley I get 862.5 rpm. The ratio between the second and third pulley is 8/1 so the final drive would 107.8 rpm.

I think, not sure, but thats wat I am going with

 

[havasu]

Man, I just got dizzy again. Seems correct IMHO.

 

[odorf]

bought a sausage grinder, View attachment 2965

i have a couple of motors and a bucket full of pulleys.

so.....

 

[StingRayCaretaker]

I built a vacuum for my lawn tractor. The rear PTO runs 540 and the vacuum needs in excess of 3,000. I stepped it up using four pulleys. No brain surgery involved, just minor math.

 

[Chris]

I believe your math is correct on this one.