Trailer Tail end bobing up and down - Page 2 - Pirate4x4.Com : 4x4 and Off-Road Forum
 
Pirate4x4.Com : 4x4 and Off-Road Forum  

Go Back   Pirate4x4.Com : 4x4 and Off-Road Forum > General Tech > Tow Rigs and Trailers
Notices

Reply
 
Share LinkBack Thread Tools Display Modes
Old 01-31-2020, 08:00 AM   #26 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
Quote:
Originally Posted by 87manche View Post
yes.

you're increasing the vertical shear of your existing frame rail.
when the frame rail wants to flex it has to act against that piece of flat steel and either compress it or stretch it.

Personally I'd do it with round bar stock.

and don't PM me for tech help. the point of the forum is to share things openly. discussing solutions via PM helps nobody in the future when they search for the topic.

I understand that the search is now useless, so I won't go full sirch n00b, but copy and paste this directly into google and start reading.
What you're doing has been done a bunch of times.

Code:
trailer truss site:www.pirate4x4.com
Okay so when putting the truss on the TOP of the main frame from back of camper infront of axle back to bumper I need to jack the rear end up and install and weld the truss to prevent sagging when loaded? Then when installing bottom truss under frame I need to be fully loaded in the rear? Would 1” round rod be to much or to little?
fzl is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 08:59 AM   #27 (permalink)
Rock God
 
DE Jeeper's Avatar
 
Join Date: Jun 2001
Member # 5295
Location: Wilmington, DE
Posts: 1,703
Quote:
Originally Posted by fzl View Post
Yes I knew that trailer frames rely strictly on the structure above the frame. Same way a enclosed trailer works. The camper part seems fine when driving down the road, its just after loading the SxS going down the road I can see the rear going up and down going down the road.
The part under the trailer may not be bouncing but in the pic it sure looks like it bending.

Its good u r doing the full length truss. I dont really have any input on the size of the material but i would mimic an existing trailer manufacture. U can look up Kaufman. They build trailers with truss and they may even tell u what they use if u call and "inquier" about buying one.

https://www.kaufmantrailers.com/wp-c...ck-trailer.jpg
__________________
'88 YJ with not much '88 YJ left

We-Rock Stock Class
Team Mall Crawler #609

Sponsored by:
The Drive Shaft Shop
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Delaware Jeep Assoc.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
DE Jeeper is offline   Reply With Quote Quick reply to this message
Sponsored Links
Old 01-31-2020, 09:15 AM   #28 (permalink)
Zeus of the Sluice
 
arse_sidewards's Avatar
 
Join Date: Feb 2013
Member # 256962
Location: People's Republic of Taxachusetts
Posts: 3,823
Quote:
Originally Posted by fzl View Post
Okay so when putting the truss on the TOP of the main frame from back of camper infront of axle back to bumper I need to jack the rear end up and install and weld the truss to prevent sagging when loaded? Then when installing bottom truss under frame I need to be fully loaded in the rear? Would 1” round rod be to much or to little?
I was just about to mention this. The ladder style reinforcements are only really effective in tension. Since the load is overhung and not supported on either end (unlike the portion of a GN or semi trailer between the wheels and truck) the bottom is in compression and the top is in tension so an over the frame ladder would be most beneficial and between the axles and pin you'd want to go under the frame.

Last edited by arse_sidewards; 01-31-2020 at 09:15 AM.
arse_sidewards is online now   Reply With Quote Quick reply to this message
 
Old 01-31-2020, 09:59 AM   #29 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
Quote:
Originally Posted by arse_sidewards View Post
Quote:
Originally Posted by fzl View Post
Okay so when putting the truss on the TOP of the main frame from back of camper infront of axle back to bumper I need to jack the rear end up and install and weld the truss to prevent sagging when loaded? Then when installing bottom truss under frame I need to be fully loaded in the rear? Would 1” round rod be to much or to little?
I was just about to mention this. The ladder style reinforcements are only really effective in tension. Since the load is overhung and not supported on either end (unlike the portion of a GN or semi trailer between the wheels and truck) the bottom is in compression and the top is in tension so an over the frame ladder would be most beneficial and between the axles and pin you'd want to go under the frame.
What material would you use? I am looking to go pick it up tomorrow and would I need to jack up the bumper when installing the truss on top of the frame to give it tension when welding?

Last edited by fzl; 01-31-2020 at 10:02 AM.
fzl is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 11:57 AM   #30 (permalink)
Registered User
 
Join Date: May 2010
Member # 161331
Location: Misery
Posts: 1,705
Quote:
Originally Posted by fzl View Post
[IMG][/IMG]

this wouldn't help at the rear?
No, since the end is unsupported the bottom side is in compression and it will do jack shit for this.

Quote:
Originally Posted by fzl View Post
Pretty much make it look like this then.

https://pjtrailers.com/options/under...llery1274%5D/0
That is great for between the axles and the hitch, in that use it's in tension.
bdkw1 is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 12:05 PM   #31 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
[/QUOTE]That is great for between the axles and the hitch, in that use it's in tension.[/QUOTE]

Okay but if I used that method on top of the frame rail in the rear would it keep it from bouncing?
fzl is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 01:34 PM   #32 (permalink)
Zeus of the Sluice
 
arse_sidewards's Avatar
 
Join Date: Feb 2013
Member # 256962
Location: People's Republic of Taxachusetts
Posts: 3,823
That is great for between the axles and the hitch, in that use it's in tension.[/QUOTE]

Okay but if I used that method on top of the frame rail in the rear would it keep it from bouncing?[/QUOTE]

Yes, but you need to run one under the frame rail from the front end of the trailer back and have them overlap substantially otherwise it will just bend where the top side one terminates.
arse_sidewards is online now   Reply With Quote Quick reply to this message
Old 01-31-2020, 01:35 PM   #33 (permalink)
Registered User
 
Join Date: May 2010
Member # 161331
Location: Misery
Posts: 1,705
Quote:
Originally Posted by fzl View Post
Okay but if I used that method on top of the frame rail in the rear would it keep it from bouncing?
Yes.
bdkw1 is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 01:41 PM   #34 (permalink)
Registered User
 
Join Date: May 2010
Member # 161331
Location: Misery
Posts: 1,705
Quote:
Originally Posted by arse_sidewards View Post
Yes, but you need to run one under the frame rail from the front end of the trailer back and have them overlap substantially otherwise it will just bend where the top side one terminates.
If he ended the top one about the middle of the front span, it would support it and he wouldn't need the bottom one.

Personally, I would chop off the axles and slap another full length 2X6X.25 under the whole thing.
bdkw1 is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 01:59 PM   #35 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
Okay what materials would y’all use to make the trusses? I am going to run one underneath and on top at the rear. Having them overlap Each other.
fzl is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 02:00 PM   #36 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
When putting truss on top of main rail in rear do I jack up the bumper to make it level before welding the truss in on main frame?
fzl is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 02:41 PM   #37 (permalink)
Zeus of the Sluice
 
arse_sidewards's Avatar
 
Join Date: Feb 2013
Member # 256962
Location: People's Republic of Taxachusetts
Posts: 3,823
Quote:
Originally Posted by fzl View Post
Okay what materials would yall use to make the trusses? I am going to run one underneath and on top at the rear. Having them overlap Each other.
1-1/2ish by 1/4 or 3/8 flat stock for the strap. Whatever tube I have around for the vertical parts.
arse_sidewards is online now   Reply With Quote Quick reply to this message
Old 01-31-2020, 02:54 PM   #38 (permalink)
Zeus of the Sluice
 
Join Date: Mar 2003
Member # 17947
Location: Upper Marlboro, MD
Posts: 3,607
Send a message via AIM to jaluhn
Okay, I'll say it.... stop messing around and get a real trailer before you kill someone. That thing is going to structurally fail and cause a wreck sooner or later, and if you have to ask as many questions as you are, you don't understand the first clue of how to actually build a trailer. Learn **why** it's built the way it is (which means actually doing research and trying to learn instead of asking someone to hold your hand) and then try again. All the discussion of trussing is meaningless if it's not done right and details matter here.

I'll all for learning and trying things, but a trailer going down the freeway isn't the place to do it.
jaluhn is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 04:00 PM   #39 (permalink)
Registered User
 
Join Date: May 2010
Member # 161331
Location: Misery
Posts: 1,705
Quote:
Originally Posted by fzl View Post
When putting truss on top of main rail in rear do I jack up the bumper to make it level before welding the truss in on main frame?
String line it and jack it up till its strait. Or laser if your fancy

I would not preload it anymore than that.
bdkw1 is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 04:29 PM   #40 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
Quote:
Originally Posted by bdkw1 View Post
Quote:
Originally Posted by fzl View Post
When putting truss on top of main rail in rear do I jack up the bumper to make it level before welding the truss in on main frame?
String line it and jack it up till its strait. Or laser if your fancy <a href="https://www.pirate4x4.com/forum/images/smilies/thefinger.gif" border="0" alt="" title="flipoff2" >:-)</a>

I would not preload it anymore than that.
10-4 and just cut all the bracing the same size correct all the way to the rear? Also what should spacing be for bracing 1ft splits?
fzl is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 04:30 PM   #41 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
Quote:
Originally Posted by arse_sidewards View Post
Quote:
Originally Posted by fzl View Post
Okay what materials would y’all use to make the trusses? I am going to run one underneath and on top at the rear. Having them overlap Each other.
1-1/2ish by 1/4 or 3/8 flat stock for the strap. Whatever tube I have around for the vertical parts.
That’s exactly what I had in mind just making sure ima use some 1-1/2 square tube 11 gauge for verticals at 1-1/2 high.
fzl is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 04:39 PM   #42 (permalink)
Registered User
 
Join Date: May 2010
Member # 161331
Location: Misery
Posts: 1,705
Quote:
Originally Posted by fzl View Post
10-4 and just cut all the bracing the same size correct all the way to the rear? Also what should spacing be for bracing 1ft splits?
Try and put them where the cross braces are. Do not weld across the strap except at the ends. Weld it on the sides.

Edit, put a bend on the end so that they sit flat on the frame rail for a couple inch's. then weld up the sides and ends but not the inside edge.

Last edited by bdkw1; 01-31-2020 at 04:40 PM.
bdkw1 is offline   Reply With Quote Quick reply to this message
Old 01-31-2020, 05:45 PM   #43 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
Quote:
Originally Posted by bdkw1 View Post
Try and put them where the cross braces are. Do not weld across the strap except at the ends. Weld it on the sides.

Edit, put a bend on the end so that they sit flat on the frame rail for a couple inch's. then weld up the sides and ends but not the inside edge.
I figured I would weld 3-4 of it flat to the frame welding it at end and both sides. then bend it to the mounts & weld them horizontal to the strap like on pj trailers. Then take the end of the strap at bumper and bend it down again and weld 3-4 to the bumper at end and sides. Does this sound correct?? Sorry Im a visual person and Im trying to get my ducks in a row.

https://pjtrailers.com/options/under-frame-bridging
fzl is offline   Reply With Quote Quick reply to this message
Old 02-01-2020, 01:52 AM   #44 (permalink)
Registered User
 
Elwenil's Avatar
 
Join Date: Jan 2005
Member # 41063
Posts: 17,379
Quote:
Originally Posted by jaluhn View Post
Okay, I'll say it.... stop messing around and get a real trailer before you kill someone. That thing is going to structurally fail and cause a wreck sooner or later, and if you have to ask as many questions as you are, you don't understand the first clue of how to actually build a trailer. Learn **why** it's built the way it is (which means actually doing research and trying to learn instead of asking someone to hold your hand) and then try again. All the discussion of trussing is meaningless if it's not done right and details matter here.

I'll all for learning and trying things, but a trailer going down the freeway isn't the place to do it.
^^^ This.
__________________
1988 Dodge AW450 Ramcharger-318TBI-NP435-NP205-D60s
Odin Owns Ye All
Elwenil is offline   Reply With Quote Quick reply to this message
Old 02-01-2020, 07:18 AM   #45 (permalink)
Registered User
 
Join Date: Feb 2007
Member # 86724
Posts: 29,992
Code:
trailer truss site:www.pirate4x4.com
[/QUOTE]

https://lmgtfy.com/?q=trailer+truss+....pirate4x4.com
__________________
Electricity is really just organized lightning.
87manche is offline   Reply With Quote Quick reply to this message
Old 02-01-2020, 04:08 PM   #46 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
I got one side done today and I can tell you it’s a hell of a lot stiffer in the rear. I got my wife to jump up and down on it while I looked under camper and the frame flex’s a little. so I will be doing the truss under the camper also overlapping the rears upper truss. Also going to run a vertical joist 2x2 half way down the camper to the bumper Might end up adding a 3rd axle in the future but still unsure about it right now. Thank you for everyone’s help.
fzl is offline   Reply With Quote Quick reply to this message
Old 02-02-2020, 02:06 PM   #47 (permalink)
Zeus of the Sluice
 
arse_sidewards's Avatar
 
Join Date: Feb 2013
Member # 256962
Location: People's Republic of Taxachusetts
Posts: 3,823
Post some pics. Wife and trailer preferred.
arse_sidewards is online now   Reply With Quote Quick reply to this message
Old 02-02-2020, 04:30 PM   #48 (permalink)
fzl
Registered User
 
Join Date: Mar 2019
Member # 865790
Posts: 32
Quote:
Originally Posted by arse_sidewards View Post
Post some pics. Wife and trailer preferred.
I will right now we are at the emergency room; my wife fell off the trailer today she has a broken femur.
fzl is offline   Reply With Quote Quick reply to this message
Old 02-05-2020, 10:30 PM   #49 (permalink)
Wheeler
 
Join Date: Sep 2009
Member # 142852
Posts: 163
Quote:
Originally Posted by jaluhn View Post
Okay, I'll say it.... stop messing around and get a real trailer before you kill someone.
Quote:
Originally Posted by fzl View Post
I will right now we are at the emergency room; my wife fell off the trailer today she has a broken femur.
IT BEGINS.
Prozon is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Pirate4x4.Com : 4x4 and Off-Road Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
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.

** A VERIFICATION EMAIL IS SENT TO THIS ADDRESS TO COMPLETE REGISTRATION!! **

Email Address:
Insurance
Please select your insurance company (Optional)

Log-in


Thread Tools
Display Modes

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



All times are GMT -7. The time now is 10:36 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0 ©2011, Crawlability, Inc.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.