The New Home for the Sheet Metal Industry Forums
SheetMetalTalk
 


Go Back   Sheetmetal Talk > Sheet Metal Forums > Sheet Metal Talk

Sheet Metal Talk
General discussion for fabrication and layout work. No advertising on forums, it will be deleted.
       


Share This Forum!  
 
 
     

 

Reply
 
Thread Tools Display Modes
  #11  
Old 11-28-2009, 05:33 PM
john_galt john_galt is offline
Professional Member
 
Join Date: Jul 2009
Location: Indpls.
Posts: 232
Thanks: 23
Thanked 45 Times in 29 Posts
Default

Well, like I said it was hard to follow.Glad you got it.But if your center line rise was 15.5 with a 36" base line, that is 23.29 degrees instead of the 22.5. Didn't mean to confuse.
Reply With Quote
  #12  
Old 11-28-2009, 09:17 PM
tinmetal tinmetal is offline
Member
 
Join Date: Feb 2009
Posts: 41
Thanks: 0
Thanked 1 Time in 1 Post
Default

if you dont wanna get confuse......whatever your size of your check elbow get size half of it..sample 30 size of your check =15 and then your distance to the throat radius add it together thats your centre line radius
Reply With Quote
  #13  
Old 11-28-2009, 09:31 PM
tonymontone tonymontone is offline
Junior Member
 
Join Date: Nov 2009
Posts: 9
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Tinmetal...your the man!!
Again thank-you for this formula, you've made it very clear..and it worked like a champ!!
Reply With Quote
  #14  
Old 10-05-2015, 04:52 PM
Good13 Good13 is offline
Junior Member
 
Join Date: Oct 2015
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Default

What if you had 45 degree elbow and a 90 degree elbow
Reply With Quote
  #15  
Old 11-20-2015, 03:07 AM
Bradleyc1982 Bradleyc1982 is offline
Member
 
Join Date: Nov 2014
Posts: 47
Thanks: 11
Thanked 0 Times in 0 Posts
Default confusion????

Quote:
Originally Posted by tinmetal View Post
(1.1414 xoffset) -2 (.414x (clr) centre line radius this is the formula
example degree of elbow: 60=.577
45=.414
30=2.00
example in your situation
45 degree elbow 48x20=72, 48 + 24 half your check is 24=72 thats your centre line radius...
(1.414x36 offset)-2(.414x72)
=50.904-2(29.808)
=50.904-29.616
=21.288 thats the length of the duct in between your on your two 45 degree elbow...

i hope this help you...
This is confusing me? Firstly what is "-2" after multiplying the offset? Is the duct Dimension 48"x20"?? This is probably really simple but can you explain it to me please????! any help much appreciated!!!!
Reply With Quote
  #16  
Old 11-20-2015, 11:19 AM
rasun rasun is offline
Member
 
Join Date: Dec 2014
Posts: 33
Thanks: 1
Thanked 0 Times in 0 Posts
Default

Any books that I can buy to learn formulas like this that would help me as a duct installer?
Reply With Quote
  #17  
Old 01-11-2016, 09:44 PM
metalmanmania metalmanmania is offline
Member
 
Join Date: Jun 2008
Location: redding, ca.
Posts: 70
Thanks: 0
Thanked 4 Times in 4 Posts
Default

No books required, open a high school geometry book, look up similar triangles, Pythagoras theorem, and trig functions and how they interact with each other. It's all about solving for lengths of a right triangle.
Reply With Quote
  #18  
Old 01-12-2016, 09:55 AM
rasun rasun is offline
Member
 
Join Date: Dec 2014
Posts: 33
Thanks: 1
Thanked 0 Times in 0 Posts
Smile

Thanks. I'm familiar with Pythagoras theorem, I have to study the rest. I get on it.
Reply With Quote
  #19  
Old 01-12-2016, 09:57 AM
rasun rasun is offline
Member
 
Join Date: Dec 2014
Posts: 33
Thanks: 1
Thanked 0 Times in 0 Posts
Default

I meant I'll get on it
Reply With Quote
  #20  
Old 03-02-2016, 08:42 PM
rasun rasun is offline
Member
 
Join Date: Dec 2014
Posts: 33
Thanks: 1
Thanked 0 Times in 0 Posts
Default

I have a fair grasp of trigonometry now. Can anyone explain why this formula is what it is? I know that 1.414 is sin45 degrees twice. How Were The Other Numbers Figured out? Where is the right triangle being formed?
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


 

All times are GMT -6. The time now is 12:05 AM.


Powered by vBulletin®
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.