Flipping leaf spring - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Suspension - Brakes - Steering
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-28-2007, 02:48 PM
cboy's Avatar
Member
 

Last journal entry: Finished
Last photo:
Join Date: Jan 2004
Location: Atwater, CA
Age: 69
Posts: 3,918
Wiki Edits: 0

Thanks: 0
Thanked 6 Times in 4 Posts
Flipping leaf spring

We've discussed this car with it's flipped over chassis on a number of other threads but I have a question about the way the leaf springs are set up.



It appears to me the leaf springs are being asked to work opposite of how they would in traditional set up. In this picture the "force" is working WITH the curvature of the main leaf and all of the sub leafs are located inside the curvature.

In a more normal set up (like the front of back of a T-Bucket) the "force" is working AGAINST the curvature of the main leaf and the sub leafs are located on the outside (or above, in the case of a T-bucket set up) of the curvature.

My question is, does it make any difference? Will the leaf spring work as effectively whether the curvature works with the force or against the force. And if so, does it also apply to quarter elliptical leaf springs?

(Hope this makes sense...I don't know my spring lingo very well.)

    Advertisement
__________________
Always learning...and sharing what I've learned. The Scratch-Built Hot Rod.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-28-2007, 03:18 PM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 62
Posts: 16,902
Wiki Edits: 5

Thanks: 20
Thanked 274 Times in 219 Posts
I agree....with the springs upside down like that, you had better have them clamped together good, because all the force is against those thin straps. I think the person that installed those didn't think of that. The main leaf is doing most, if not all of the work.
__________________
Ontario Rodders

Budget RVs
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-28-2007, 04:08 PM
Registered User
 
Last wiki edit: Mopar tapered axle rear brake conversion
Last journal entry: What I'm doing now...
Last photo:
Join Date: Jan 2002
Posts: 4,267
Wiki Edits: 49

Thanks: 0
Thanked 5 Times in 5 Posts
You know..... there's being different and then there's being weird. You have to wonder what the spring action would be like if he ever hit a pot hole.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-28-2007, 04:29 PM
steve t's Avatar
ex biker, now hotrodder
 
Join Date: Mar 2005
Location: NC
Age: 64
Posts: 863
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
what is with those front tires, big is ugly ok i see now, it would drag the ground, still ugly
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-28-2007, 05:35 PM
S10xGN's Avatar
Gotta love a turbo!
 

Last journal entry: Body on Frame today.
Last photo:
Join Date: Aug 2004
Location: Port Neches, TX
Age: 61
Posts: 1,667
Wiki Edits: 0

Thanks: 0
Thanked 62 Times in 58 Posts
Completely unsafe! If a tire ever blew, that thing would be seriously dragging frame!

Russ
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-28-2007, 05:56 PM
cboy's Avatar
Member
 

Last journal entry: Finished
Last photo:
Join Date: Jan 2004
Location: Atwater, CA
Age: 69
Posts: 3,918
Wiki Edits: 0

Thanks: 0
Thanked 6 Times in 4 Posts
Sorry. Maybe I used the wrong picture/example to clarify my question. I really didn't want to get into another discussion about the looks, safety etc. of this particular car.

My question was a more technical one. Do leaf spings provide the same spring rate in either direction - going with the curvature of the spring or against the curvature of the spring (assuming the supporting secondary leaves are stacked on the appropriate side of the primary leaf each time.
__________________
Always learning...and sharing what I've learned. The Scratch-Built Hot Rod.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-01-2007, 12:50 AM
aka Duke of URL
 
Last wiki edit: Finding vacuum leaks Last photo:
Join Date: Oct 2001
Location: Rockville, MD
Posts: 4,821
Wiki Edits: 1

Thanks: 0
Thanked 0 Times in 0 Posts
The theory is a little beyond me but heavy truck use inverted springs on the tandems (MACK-TIMKEN).

I don't know about this though. I guess as long as a shackle kit allows the spring asm. to expand/contract...
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-02-2007, 10:11 AM
Registered User
 

Last journal entry: Lessons learned, how to's, etc...
Last photo:
Join Date: Aug 2006
Location: Manhattan, KS
Age: 36
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I did mine a little differently than he did, but it works good, no problems with potholes. His (above picture) biggest problem is that, as someone correctly pointed out, his frame'll drag if he blows a tire. My axle is under the springs, and my springs are de-arched to keep the front up, and it won't drag if I get a flat. Google American Underslung sometime.

pics: semi-recent, and early in the process (lots of trial and error to get it where it is now).
Attached Thumbnails
Click image for larger version

Name:	20Jul06_2.jpg
Views:	244
Size:	45.9 KB
ID:	18985   Click image for larger version

Name:	axle.jpg
Views:	309
Size:	28.2 KB
ID:	18986  
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-02-2007, 10:18 AM
xntrik's Avatar
Save a horse, Ride a Cowboy.
 
Last photo:
Join Date: Jul 2005
Location: Arkansas
Posts: 5,131
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by cboy
Sorry.

My question was a more technical one. Do leaf spings provide the same spring rate in either direction - going with the curvature of the spring or against the curvature of the spring (assuming the supporting secondary leaves are stacked on the appropriate side of the primary leaf each time.
Yes, they are the same.
If you flip the springs as he did, just rearrange the leaves from the outside of the arch to the inside, restacking in sequence, and the spring rate is the same but working in the opposite direction.
Looking carefully you will see that when the axle moves up away from the frame in normal comression thus increasing the arch, the spring is compressing all the leaves in the same manner as the inverse style.

This works for any leaf spring, semi-eliptical or quarter-eliptical.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-02-2007, 12:03 PM
cboy's Avatar
Member
 

Last journal entry: Finished
Last photo:
Join Date: Jan 2004
Location: Atwater, CA
Age: 69
Posts: 3,918
Wiki Edits: 0

Thanks: 0
Thanked 6 Times in 4 Posts
Quote:
Originally Posted by xntrik
Yes, they are the same.
If you flip the springs as he did, just rearrange the leaves from the outside of the arch to the inside, restacking in sequence, and the spring rate is the same but working in the opposite direction.
Looking carefully you will see that when the axle moves up away from the frame in normal comression thus increasing the arch, the spring is compressing all the leaves in the same manner as the inverse style.

This works for any leaf spring, semi-eliptical or quarter-eliptical.
Excellent xntrik. Exactly the info I needed. I may not do the flipping, but it allows me a lot more design flexibility to know I could install the springs in either configuration.
__________________
Always learning...and sharing what I've learned. The Scratch-Built Hot Rod.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-02-2007, 12:13 PM
cboy's Avatar
Member
 

Last journal entry: Finished
Last photo:
Join Date: Jan 2004
Location: Atwater, CA
Age: 69
Posts: 3,918
Wiki Edits: 0

Thanks: 0
Thanked 6 Times in 4 Posts
Quote:
Originally Posted by PharaohChris
I did mine a little differently than he did....
Thanks for the pics. I can understand how you would have to do a bit of trial and error to get the final ride height correct. I'm trying to design some "adjustability" into my front and rear suspensions so that I'll be able to correct for the spring rates/compression etc. without having to tear everything apart once I discover I'm either riding too low or too high.

BTW, I'd enjoy seeing some additional shots of your rod and some close ups, particularly the suspension work. Maybe start a journal or just post them up in your photo gallery and then PM me.

Dewey
__________________
Always learning...and sharing what I've learned. The Scratch-Built Hot Rod.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 03-02-2007, 09:12 PM
Registered User
 
Join Date: Sep 2005
Location: california
Posts: 9
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by cboy
Sorry. Maybe I used the wrong picture/example to clarify my question. I really didn't want to get into another discussion about the looks, safety etc. of this particular car.

My question was a more technical one. Do leaf spings provide the same spring rate in either direction - going with the curvature of the spring or against the curvature of the spring (assuming the supporting secondary leaves are stacked on the appropriate side of the primary leaf each time.
to my understanding a leaf spring needs to have compression to work ...this cars spring set up will not compress under any driving situation .the springs are only holding up the frame and the car will handle the same as if the axle were welded to the frame.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 03-03-2007, 12:07 AM
Registered User
 
Join Date: Jul 2006
Location: carlsbad ca.
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I don't think that works at all, Who built that thing???
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 03-03-2007, 01:04 AM
Member
 
Last wiki edit: Vacuum brake bleeder set up
Join Date: Nov 2003
Location: So Cal
Posts: 1,245
Wiki Edits: 8

Thanks: 0
Thanked 0 Times in 0 Posts
Springs work just fine with negative arch as long as they are made that way. Running a spring with negative arch will change your anti-dive, roll center, and the axle roll axis. In RCVD (Milliken & Milliken's Race Car Vehicle Dynamics) p.662 is a diagram on how to figure out all those things. Anti-dive won't matter because there are no front brakes , and with how low that thing is I doubt there is enough wheel travel that you would really care about the roll center or axle roll axis. The only thing I would really worry about would be the open part of the spring eye is looks to be on the bottom of the leaf. It should be on the top.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 03-05-2007, 07:49 AM
Registered User
 

Last journal entry: Lessons learned, how to's, etc...
Last photo:
Join Date: Aug 2006
Location: Manhattan, KS
Age: 36
Posts: 6
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by knotheads
to my understanding a leaf spring needs to have compression to work ...this cars spring set up will not compress under any driving situation .the springs are only holding up the frame and the car will handle the same as if the axle were welded to the frame.
Speeking from three years of personal experience with the underslung design, I can assure you, you are wrong in your thinking. I wish I had a video camera so I could make a video of my front axle as I drove down the road. I'm quickly wearing the paint off the front cross member by bouncing on it at shows just to prove that the design works .

I know you didn't ask, but the underslung design came about in 1905...
Attached Thumbnails
Click image for larger version

Name:	amunder.jpg
Views:	134
Size:	24.3 KB
ID:	19122  
Reply With Quote Quick reply to this message

Recent Suspension - Brakes - Steering posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Leaf Spring Data base nautius Suspension - Brakes - Steering 8 11-05-2006 11:25 AM
rear leafs to stiff 2112jb Suspension - Brakes - Steering 12 10-06-2005 07:29 AM
TCI's rear leaf spring installation gavinpierce Suspension - Brakes - Steering 9 06-23-2005 06:00 PM
Who makes a 52" x 1.75" leaf spring? jpd37 Suspension - Brakes - Steering 5 10-14-2004 11:59 AM
8 1/4 to 8 3/4 rear end Leaf Spring Problem... 71gtx Transmission - Rearend 21 04-19-2004 07:17 AM


All times are GMT -6. The time now is 09:12 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.