Shop Floor Talk  

Go Back   Shop Floor Talk > Welding and Metalworking Forums > Mechanical & Electrical

SFT Search:   
Reply
 
Thread Tools Display Modes
  #11  
Old 04-04-2020, 10:42 PM
Shade Tree Welder's Avatar
Shade Tree Welder Shade Tree Welder is offline
Grumpy Bastard
 
Join Date: Jun 2004
Location: Kankakee County, IL
Posts: 20,170
Default

Quote:
Originally Posted by digr View Post
:d

lol I know how to figure ratio, it's ration that I have a problem with.
I guess you did not like my answer...

Quote:
Originally Posted by chumly2071 View Post
All the 36s we built were 1/2 hp. Being a belt drive, and looking at the number of blades, I'm going to throw a guess of 600-650 RPM. Put a pulley on the motor, and do a quick clamp on ammeter check to see if you're where you need to be. Ideally you'll have a specific speed for a blade at a certain static pressure to give you the best efficiency. As a box fan moving air, static pressure is a moot point. Don't spin it too fast (whatever yhe real rated speed is) as the blades can fatigue crack and exit spectacularly. Any markings on the fan to id make and model?
Engineers...
__________________
Shade

"Prepare to defend yourselves."
-- Sergeant Major Basil L. Plumley, Ia Drang Valley
Reply With Quote
  #12  
Old 04-04-2020, 11:10 PM
chumly2071's Avatar
chumly2071 chumly2071 is offline
Urban Gunfighter
 
Join Date: Jun 2004
Location: IL, south of Shade Tree Welder
Posts: 2,580
Default

Quote:
Originally Posted by Shade Tree Welder View Post
Engineers...
It's not like I designed these things or anything...
__________________
Tool junkie with a Jeep problem...


"I am a man of peace, but if war comes to my door it will find me home."
Reply With Quote
  #13  
Old 04-05-2020, 12:02 AM
Shade Tree Welder's Avatar
Shade Tree Welder Shade Tree Welder is offline
Grumpy Bastard
 
Join Date: Jun 2004
Location: Kankakee County, IL
Posts: 20,170
Default

Quote:
Originally Posted by chumly2071 View Post
It's not like I designed these things or anything...
No, you just like blowing up transformers...
__________________
Shade

"Prepare to defend yourselves."
-- Sergeant Major Basil L. Plumley, Ia Drang Valley
Reply With Quote
  #14  
Old 04-05-2020, 12:05 AM
chumly2071's Avatar
chumly2071 chumly2071 is offline
Urban Gunfighter
 
Join Date: Jun 2004
Location: IL, south of Shade Tree Welder
Posts: 2,580
Default

Quote:
Originally Posted by Shade Tree Welder View Post
No, you just like blowing up transformers...
That too. I was very good at it.
__________________
Tool junkie with a Jeep problem...


"I am a man of peace, but if war comes to my door it will find me home."
Reply With Quote
  #15  
Old 04-06-2020, 08:26 AM
OldRedFord's Avatar
OldRedFord OldRedFord is offline
Kibble King
 
Join Date: Mar 2005
Location: Hull GA
Posts: 3,769
Send a message via AIM to OldRedFord Send a message via Yahoo to OldRedFord
Default

Quote:
Originally Posted by chumly2071 View Post
All the 36s we built were 1/2 hp. Being a belt drive, and looking at the number of blades, I'm going to throw a guess of 600-650 RPM. Put a pulley on the motor, and do a quick clamp on ammeter check to see if you're where you need to be. Ideally you'll have a specific speed for a blade at a certain static pressure to give you the best efficiency. As a box fan moving air, static pressure is a moot point. Don't spin it too fast (whatever the real rated speed is) as the blades can fatigue crack and exit spectacularly. Any markings on the fan to id make and model?

Sent from my SM-G920V using ShopFloorTalk mobile app
Yup.

Twister model A36G

Acme Engineering & Manufacturing Corp
__________________
Tim
Self appointed director of junk, and old vehicles.
Reply With Quote
  #16  
Old 04-06-2020, 11:45 AM
chumly2071's Avatar
chumly2071 chumly2071 is offline
Urban Gunfighter
 
Join Date: Jun 2004
Location: IL, south of Shade Tree Welder
Posts: 2,580
Default

Looking back trough an old University of Illinois fan performance book (results tabulated in 1999 from several years worth of tests (I worked in the lab that did these tests while I went to school, and it got me my first job out of school)), it looks like most of the belt drive ACME stuff was 580 or 635 RPM (back then, anyway).
These were all fan panels in housings with an inlet shutter for AG applications.

I'd put a 1/2 HP 1725 motor on, Totally Enclosed Air Over (TEAO) and shoot for the 580 range and then check the amperage the motor is drawing. Speed up or down with pulley changes based on comparison to the motor rated amps. A Magnetek C580 would be a good choice, but is an old catalog number.

A lot of the product shown is still mine (from over 20 years ago... AP and Cumberland
__________________
Tool junkie with a Jeep problem...


"I am a man of peace, but if war comes to my door it will find me home."
Reply With Quote
  #17  
Old 04-06-2020, 09:10 PM
OldRedFord's Avatar
OldRedFord OldRedFord is offline
Kibble King
 
Join Date: Mar 2005
Location: Hull GA
Posts: 3,769
Send a message via AIM to OldRedFord Send a message via Yahoo to OldRedFord
Default

Quote:
Originally Posted by chumly2071 View Post
Looking back trough an old University of Illinois fan performance book (results tabulated in 1999 from several years worth of tests (I worked in the lab that did these tests while I went to school, and it got me my first job out of school)), it looks like most of the belt drive ACME stuff was 580 or 635 RPM (back then, anyway).
These were all fan panels in housings with an inlet shutter for AG applications.

I'd put a 1/2 HP 1725 motor on, Totally Enclosed Air Over (TEAO) and shoot for the 580 range and then check the amperage the motor is drawing. Speed up or down with pulley changes based on comparison to the motor rated amps. A Magnetek C580 would be a good choice, but is an old catalog number.

A lot of the product shown is still mine (from over 20 years ago... AP and Cumberland
So a 3" drive pulley on the 1725 rpm motor would be a good start.

Looking at it more I think it needs bearings.
__________________
Tim
Self appointed director of junk, and old vehicles.
Reply With Quote
  #18  
Old 04-06-2020, 11:42 PM
LKeithR's Avatar
LKeithR LKeithR is offline
Hey...wait...is there a prize?
 
Join Date: Aug 2011
Location: Langley, B.C.
Posts: 5,227
Default

Quote:
Originally Posted by OldRedFord View Post
...So a 3" drive pulley on the 1725 rpm motor would be a good start...
That would be a good start--should give you about 575 RPM...
__________________
Keith

Measure twice and cut once...or...wait, was that the other way around?
Reply With Quote
  #19  
Old 04-07-2020, 09:14 AM
randydupree's Avatar
randydupree randydupree is offline
Why, Hell Yes!
 
Join Date: Aug 2005
Location: Bainbridge Ga
Posts: 6,192
Default

I would slow the fan down,i like a nice gentle breeze,not a hurricane.
With speed comes noise,and you can't weld anywhere near the fan.
If your trying to dry a wet floor,you need high fan speed.
Now if your going to mount this fan way high in a wall and have it suck out,high speed will be better,except for the noise.

I was assuming (bad thing) that you were planing on mounting the fan on a cart with wheels so it can follow you around the shop.

Ceiling fans would be a better choice.
A friend had a old worn out wood airboat prop mounted on a stand,it turned slow but moved a lot of air,and it was quiet.
That prop may have been 80'' .
Reply With Quote
  #20  
Old 04-07-2020, 10:23 AM
greywynd's Avatar
greywynd greywynd is offline
I can dig it
 
Join Date: Dec 2005
Location: Wainwright, Alberta
Posts: 5,158
Default

One of the most impressive air movers I’ve seen are ceiling fans called ‘big ass fans’. Look them up. As Randy says, not necessarily fast, though they move a lot of air.


Sent from my iPhone using ShopFloorTalk mobile app
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Jump

Web Search:

All times are GMT -5. The time now is 04:47 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.