I want to build my first trailer

[mcarrara]

I have been thinking of building a trailer to tow behind my JK. I am leaning towards a aluminum frame using Huck bolts (based on the Schutt trailer, only not so beefy). I have two questions about design:
1. How to you decide how long to make the tongue?
2. How to determine the best axle placement (front to back)?

I am planning on taking a year to build the trailer. I am hoping to have the frame built this summer and an axle(torsion suspension) next fall. Then late fall and winter I can test drive the trailer before I commit to a body.

I am still deciding on the body style, but I am pretty set on making it out of a composite sandwich(fiber reinforced plastic over foam).

I'm sure I will be asking lots of questions over the life of this build.

 

[Geodoc]

Here's a good link - http://www.angib.pwp.blueyonder.co.uk/teardrop/Tongue%20strength%20unified%20simple.pdf - don't know how it would apply to aluminum, though.

 

[AA1PR]

another good place to find info is http://tventuring.com/trailerforum/index.php

 

[mcarrara]

Here's a good link - http://www.angib.pwp.blueyonder.co.uk/teardrop/Tongue%20strength%20unified%20simple.pdf - don't know how it would apply to aluminum, though.

While the link is for steel, it gives me some basic ideas on length and geometry. I never thought about length vs payload. I was more concerned with length vs drivability.

Does anyone have opinions on how tongue length effects drivabilty? Obviously turning radius is effected, but what about lateral motion (sway) or bouncing. While the trailer is for off-road I still have to drive on the highway to get there.

 

[mcarrara]

another good place to find info is http://tventuring.com/trailerforum/index.php

Thanks I can search the forum for more info.

 

[skersfan]

Most will tell you 60/40 and have the trailer level.

I do not follow that for numerous reasons. A lot depends on how the trailer is set up, where you carry certain things. IE. Water tank on the front makes the trailer very tongue heavy when full, squirrely when empty.

What I have used for over 30 years is for every foot of box, cargo area, move the axle one inch behind center of the cargo area. IE 12 foot box area, 12 inches behind center. This will normally give a trailer that tows at over 100mph and yet can be moved around by hand if it is needed. I also set the front of the trailer at the ball.hitch 2 inches lower than the rear, this helps with down draft on the tongue, increases stability and changes the center of gravity.

I would suggest you give what you plan to build a lot more thought, where things will be before you just build a frame. Where things are placed or designed to be can totally change the way a trailer performs, on and off road. Keep your water low and centered over the axle if possible, same with the battery, but if you can not, be sure to plan counter balancing with a spare or something.

There is a lot more thought required to make a trailer that works, rather than something you pull.

 

[mcarrara]

Most will tell you 60/40 and have the trailer level.

I do not follow that for numerous reasons. A lot depends on how the trailer is set up, where you carry certain things. IE. Water tank on the front makes the trailer very tongue heavy when full, squirrely when empty.

What I have used for over 30 years is for every foot of box, cargo area, move the axle one inch behind center of the cargo area. IE 12 foot box area, 12 inches behind center. This will normally give a trailer that tows at over 100mph and yet can be moved around by hand if it is needed. I also set the front of the trailer at the ball.hitch 2 inches lower than the rear, this helps with down draft on the tongue, increases stability and changes the center of gravity.

I would suggest you give what you plan to build a lot more thought, where things will be before you just build a frame. Where things are placed or designed to be can totally change the way a trailer performs, on and off road. Keep your water low and centered over the axle if possible, same with the battery, but if you can not, be sure to plan counter balancing with a spare or something.

There is a lot more thought required to make a trailer that works, rather than something you pull.

I agree whole heartily with that last line. That's why I plan to test thing out at various points. I have a general layout in mind. The trailer will be 10' long with a 3' tongue. The front third is for batteries, generator/inverter and propane tank. The next third is for water, cooler or refrigerator and fuel cans. The last third is general storage, food, camp supplies and the like. Tools and recovery gear are in the Jeep.

Currently I set up a 'base' camp and take day trips from there. It is not a true expedition adventure. Because I will be away from the trailer much of the day I want tools and recovery gear with me.