HP and RPM

Can't give you any useful answer without at least two more pieces of information:

• Is the conveyor horizontal?
• What torque at the pulley (or force at the belt) is needed to overcome friction?

The conveyor is horizontal. what do you mean by force? All i know is they want it to go 125-180 fpm and have 5-6 packages (the biggest one being 5"w x 13"l x 1.5"h) each min go accross it. they want a 115/60/1 motor. The infeed onto the conveoyor will be 150 fpm. Thats all i have for info. The pulley dia on the belt at the motor is 3.961".

Since the infeed is about the same speed as the conveyor, there'll be very little (if any) power required to accelerate the packets. As it's horizontal, there'll be no component due to gravity.

Imagine that there was no friction in the system (pulley & roller bearings etc.), and the belt was perfectly flexible (chain belts can be close to this). Shove a packet on at one end, 150fps, and it would go all the way to the other end, no power required.

The force you need to overcome to move the belt with the parcels on it is (mostly) friction.

The drive drum on a conveyor has a sprocket. It is driven by a gear reduced motor. RPM of the motor divided by the gear reduction which is on the name plate of the gear reducer this will give the output shaft RPM. The ratio of the number of teeth on the drive sprocket on the gear reducer to the driven sprocket on the conveyor roller will give you the roller RPM. RPM of the roller times its circumference will give you belt speed.

Load on a conveyor is in lbs/sq ft on the belt. The width and length of the belt has to be considered.