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Discussion Starter #21
I guess what u didnt (or maybe did) understand is that the box on the original trailer was designed to give it the stiffness it needed.

My 28' open deck 14k goose has 10" I-beams running underneath supporting a deck thats a little lighter then your entire trailer. Maybe im being dramatic but that thing looks like a disaster waiting to happen. Everything on that trailer looks way too light to hold the weight and the wheels r too far foward.

It needs I-beams or several trusses welded in.
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, it’s just after loading the SxS going down the road I can see the rear going up and down going down the road.
 

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Discussion Starter #22
I guess im not understanding the tension rod your talking about. Im sorry not really set on anything just trying to understand about the tension rod.
you're effectively increasing the height of you stressed member with a truss.


the further the top of your truss is from the frame rail the stronger it will be.
You're basically building a bridge.

it definitely needs to extend all the way to the front, or you're just going to fatigue wherever it stops and it will eventually crack.
What material should I use to make this truss to be able to get it in between the axle hangers?
 

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run truss to spring hangers
transistion truss to the top
run over axles
transition truss back to the bottom.

that's what I would do.
 

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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
 

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Discussion Starter #26
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?
 

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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, it’s 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-content/uploads/2013/04/three-car-gooseneck-trailer.jpg
 

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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.
 

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Discussion Starter #29 (Edited)
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?
 

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Discussion Starter #31
[/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?
 

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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.
 

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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.
 

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Discussion Starter #35
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.
 

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Discussion Starter #36
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?
 

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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.
 

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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.
 

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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 :flipoff2:

I would not preload it anymore than that.
 

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Discussion Starter #40
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="http://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?
 
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