Trailer design, help needed

ptulli

Advanced Member
Joined
Jan 17, 2021
Posts
41
Hi guys! I got a design I am working on for a 5x8 off-road square drop. I got the box design ok but I am having a hard time with on how best do get the trailer built. I am only towing with a 2dr Wrangler JK so 2000lb for towing capacity. I'd love to do aluminum but my brother only welds metal. So I am thinking of 2x2 square tube and I will run the tongue all the way back for a recovery point. I am going to go with the Timbren suspension as well and try to make a spot under the trailer for water and a small storage spot for the RVQ. My question is on the design below how should I space the cross members and what to use for the angle to connect to the tongue. Oh and I will also make the end of the tongue removable to swap between the articulating hitch and a regular. Thanks for any and all help!

image.php
 
For the crossmembers just divide the space equally, but you should also have one at the Timbrens.

I'm reading your 2nd question 2 ways, but that's just me.

1. For the tongue bracing run it from the outside most point of your 2nd crossmember, that will give you 4 attachment points to the frame.
2. 2x2x.25 angle but I'd stick with the 2x2 sq tube.
 
My question is on the design below how should I space the cross members and what to use for the angle to connect to the tongue.

I agree with Jasen. Just equally space the cross members. I'm not sure what you mean about your second question about the angle and the tongue. But a triangle would really strengthen it up.

NlocEWY.jpg


:thinking:

Tony
 
tony.latham":pkj6jzcj said:
My question is on the design below how should I space the cross members and what to use for the angle to connect to the tongue.

I agree with Jasen. Just equally space the cross members. I'm not sure what you mean about your second question about the angle and the tongue. But a triangle would really strengthen it up.

NlocEWY.jpg


:thinking:

Tony

The angle of that triangle is what I was referring to, didn't know if it wasn't anything special so make sure the tongue is long enough. I will make sure to have the rear tailgate door be able to open.
 
I'm getting ready to weld up my 5x10 frame this coming weekend. 2x2x1/8"(11ga) tubing with Timbren 2000HD suspension.
A couple of thoughts from the layout work I've done so far. (and mind you, I am a complete and total newbie on this process. I learn from guys like Tony, and lots of research).
1. You either have to put a 2x2x1/8 or 1/4 torque/stability bar between the two Timbren units, OR add additional bracing on the inside of the frame above the Timbren plate. I'm choosing to do the latter, using the sketch Timbren provides, and putting a cross bar directly in front of the Timbren units (leaving about 1/4" gap to ensure the Timbren unit isn't sitting on a weld. It's possibly belt&suspenders, but I'm good with that.
2. Be aware that the reinforcement plate, which looks like it's 2" wide - is really 3" wide. I spent last night cutting a piece of 3x3 tube in half on the diagonal and trimming it to get a 2"x3" that I can add the gussets to. Really check the dimensions on the Timbren sheet carefully! (I didn't at first)
3. Make sure you do your math on the cross-beam. The axle needs to be at 35% (or whatever you are using), not the pivot. That needs to be 15" further forward.

My .02 for whatever it's worth - again, I still haven't put torch to metal on the frame yet. I'm still in the measure (3x at least), cut and grind stage!

marsh
 
As mentioned in the last post, here's the "Timbren gusset" option instead of relying on the torque tube. I still have to trim the gusset plates, and shine everything up a bit. These will get sandblasted and powdercoated along with the frame.
image.php


marsh
 
when spacing your cross beams it is wise to consider the standard dimensions of materials available in your area

for using 4' x 8' sheeting the centers of your cross beams need to fall @ increments of 12", 16" 24", 48" w/ a center cross beam @ 48" on center from the ends

sw
 
tony.latham":3lxw57ks said:
The angle of that triangle is what I was referring to
Does that help?
:thinking:
Tony

Thanks Tony that does help. The angle I was talking about I circled in the picture.
image.php


For mnswamp and swoody126, thanks for the great info on the Timbren. I will be sure to show my brother all of this as he will be doing the welding. Anything helps and I do appreciate it. Trying to get it all planned ahead of time to make things easier when it's time to actually put in the work.
 
If you are anything like me, and getting the miter saw to lock on a precise angle is a near impossibility, get it close, mark the tube and 'tune' it with a flap wheel. The exact angle here is less important than having as much contact with both the longitudinal rail and the cross-bar, and that you have good surface-surface contact for the welds.
One other note - one of my shop buddies suggested recessing the end of this support by about 1/8" so that it doesn't come quite level with the outer sidewall of the trailer. His logic is that it will help keep your shin from intersecting with the sharp corner at end of the beam... I plan on taking his advise - and 3D printing end-plugs to further reduce the pain.
 
Nothing against Tony's design, as it uses the center tongue member to attach a straight tongue coupler; just saying if you plan to use the standard A-frame style coupler with just the two outer members, they are set at 50 degrees included (25/65 each side).
 
I just finished my off road frame. My first suggestion would be make it at least 9'. That extra 1' makes a huge difference in the galley. Second, I did not get all worked up about the tongue angles. I just laid one on the frame, adjusted it where it looked right, made at least 3 connection points, and marked it. Then cut two. Worked great.
I put 35' tires on so is just a bit heavy at 570 lbs with 25" clearance. That will settle after the build.
image.php
 
KCStudly":1mnvl5s3 said:
Nothing against Tony's design, as it uses the center tongue member to attach a straight tongue coupler; just saying if you plan to use the standard A-frame style coupler with just the two outer members, they are set at 50 degrees included (25/65 each side).

I Have Two trailers using a standard off the local shelf 50 deg coupler style,
I have seen these used on overloaded dump trailers :shock:

I am also planning a trailer rolled 20 deg R instead of angled sides and top :thinking: Foamie & Light
 
Onajourney":5yalghha said:
I just finished my off road frame. My first suggestion would be make it at least 9'. That extra 1' makes a huge difference in the galley. Second, I did not get all worked up about the tongue angles. I just laid one on the frame, adjusted it where it looked right, made at least 3 connection points, and marked it. Then cut two. Worked great.
I put 35' tires on so is just a bit heavy at 570 lbs with 25" clearance. That will settle after the build.
image.php

Great design, I'm hoping to be a bit lighter but i doubt it lol. Looks a lot like what I am thinking of. What are you using for axels?

Not sure if I will be using the A-frame style as I plan on using the off road articulating hitch, but also may make part of it removable. Just thinking ahead.
 
PTulli- I can't exceed 2000lb gross weight being my TV is a Jeep JK. I was going to use 2000lb Flexrides but there was a 10 week lead. I got a pair of 2000 lb Rigid Hitch Torsion axels on Amazon cheap and quick. Nearly the same as the Flexrides. There a bit of a PITA to mount but they worked out.
 
All 2 dr JK's or just 4 cyl?

V6 Unlimited (4 dr) is 3500 lbs. My old straight 6 TJ 2 dr was 3000 lbs.
 

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