Welcome to OnlineConversion.com Forums

 OnlineConversion Forums Convert Hz to RPM to FPM
 [ Home ] [ Forum Home ] Register FAQ Calendar Search Today's Posts Mark Forums Read

 Convert and Calculate Post any conversion related questions and discussions here. If you're having trouble converting something, this is where you should post.* Guest Posting is allowed.

#1
10-21-2013, 12:18 PM
 John Young Junior Member Join Date: Oct 2013 Posts: 2 Rep Power: 0
Convert Hz to RPM to FPM

I have a motor that rotates at 1800 RPM at 60 Hz. It then runs through a 15:1 gearbox that spins a 4" work roll. How do I calculate the FPM of the work roll based on different frequencies and work roll diameters? I not only want to know the formula, but also how the formula is derived. Its been driving me crazy!!!
#2
10-21-2013, 12:34 PM
 JohnS Moderator Join Date: Dec 2007 Location: SE Michigan, USA Posts: 9,438 Rep Power: 19
Re: Convert Hz to RPM to FPM

Quote:
 Originally Posted by John Young I have a motor that rotates at 1800 RPM at 60 Hz. It then runs through a 15:1 gearbox that spins a 4" work roll. How do I calculate the FPM of the work roll based on different frequencies and work roll diameters? I not only want to know the formula, but also how the formula is derived. Its been driving me crazy!!!
Work roll turns at 1800 RPM/15 = 120 RPM

Each revolution advances the work the circumference of roll, pi*d
4" = (1/3) ft so
120 rev x pi x (1/3) ft/rev = 40*pi ft/min ~ 125.66 FPM
#3
10-24-2013, 06:27 AM
 John Young Junior Member Join Date: Oct 2013 Posts: 2 Rep Power: 0
Re: Convert Hz to RPM to FPM

OK, thanks, but how does that equate to Hertz?
#4
10-25-2013, 04:23 AM
 JohnS Moderator Join Date: Dec 2007 Location: SE Michigan, USA Posts: 9,438 Rep Power: 19
Re: Convert Hz to RPM to FPM

Quote:
 Originally Posted by John Young OK, thanks, but how does that equate to Hertz?
There is not necessarily a simple connection. At 60 Hz, a sybchronous motor with two poles turns at 3600 RPM, 4 poles 1800 RPM, etc. An induction motor always slips a little (depending on load) with respect to the electrical frequency, so a four pole induction motor might only be around 1600-1700 RPM.

The electrical field rotation rate is 60 Hz times the number of pole pairs (poles/2) times 60 seconds per minute, for two pole winding 3600 cycles per minute, for four pole 1800 cycles per minute.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may post new threads You may post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Main Forums     Convert and Calculate     Resources     General Chat

All times are GMT -8. The time now is 10:50 AM.