steel tube thickness

[campertime]

i want to build a light weight 4x8 or possibly 5x8.the 4x8 will be under 500lbs,the 5x8 about 650.i'd like to use2x2"x1/16th wall sq tube,with a style supports for the tongue,i'm trying to cut 20 lbs here and there to achive the weights.
thanks for any input

[asianflava]

You probably can cut the perimeter framing thickness, but I wouldn't skimp on the tongue. You may want to add localized thickness to the axle/spring mounting points. If you do stay within your weight goal, I wouldn't use anything less than 1/8in for an a-frame tongue.

[Shadow Catcher]

Or go with aluminum.

[campertime]

does anyone know if 2x2x1/8" would be adequate for the frame 2x3x1/8th for the tongue?

[Trackstriper]

A good place to get started with the tongue question is in the design library:

http://www.angib.pwp.blueyonder.co.uk/teardrop/tear84.htm

My 6x12 cargo trailer rated at 3000# does just fine with a 2x3x1/8"A-frame tongue, so that would be way overkill for you if you are going A-frame. I have a factory 4x6 cargo trailer that is rated for 2000# that uses a 2x3x1/8" single tube tongue, with the tube oriented horizontally rather than vertically, that is, "flat" if you want to think about it that way. This seemed counter-intuitive to me at first, but it has enough vertical strength and the extra width helps to keep sway forces in check.

My instinct is that if you can keep the weight of the trailer down and wish to go with an A-frame tongue you could probably use 2x2x14 gage (0.083") for the frame and tongue. That would save you a pound per foot of tubing over using 1/8" wall 2x2. Check Andrew's charts and determine your tongue style and tongue length. See what might work. I think the concern with 1/16" wall tube is probably valid unless you did some local reinforcing...probably strong enough but you'd have to be careful with execution of design. A lot of this depends on how well things are welded. Keep seeking opinions.

[campertime]

After doing more research,i like the idea of aluminum,appears to have excellent strength using 2x2x1/8",any opinions on this for my frame,the frame itself will be 48x75" the trailer should be less than 500lbs loaded with goods.

[angib]

If you want to build light, then you need to start thinking "what do I really need" rather than "how do I build a normal teardrop lighter".

So most the the rectangular frame of a normal teardrop is just a platform to build the body on and isn't needed to tow it down a highway, so why add it?

Here is a chassis for a 5x8 body that is based on my Pico-Light design:
http://www.angib.pwp.blueyonder.co.uk/images/pico-light-chas-5x8.pdf

This is only suitable for a light body and it has to be well-built - all joints glued, for example - but this allows you to use a frame of only about 50 pounds.

Andrew

[dh]

My $0.02,

use a torsion axle, it will replace an X member.

[Micro469]

If you want to build light, then you need to start thinking "what do I really need" rather than "how do I build a normal teardrop lighter".

So most the the rectangular frame of a normal teardrop is just a platform to build the body on and isn't needed to tow it down a highway, so why add it?

Here is a chassis for a 5x8 body that is based on my Pico-Light design:
http://www.angib.pwp.blueyonder.co.uk/images/pico-light-chas-5x8.pdf

This is only suitable for a light body and it has to be well-built - all joints glued, for example - but this allows you to use a frame of only about 50 pounds.

Andrew

Andrew, for a trailer around 1000 lbs, would 1" tubing be enough around the perimeter and cross pieces? As long as the tongue is a 2x2 welded to the crosspiece holding the axle (also a 2x2) would this be strong enough??

[asianflava]

does anyone know if 2x2x1/8" would be adequate for the frame 2x3x1/8th for the tongue?

I had a 2x2x1/8 single tube tongue on a heavier trailer, the important word being "had". If you are doubling it up (a-frame) and have a lighweight trailer you should be OK.

[campertime]

Thanks for all the help.after further research i think i'd like to build it similar to the little guy construction 3/4" sidewalls and use 1x2 spars.standing on edge,the sides should give the trailer a lot of strength,i could use 1/2" plywood floor also helping to strengthin everything.the more i look i want mine to be similar to a rascal trailer,13 " wheels,and about 3 inches taller,about 45"x90" sides.i will either double up on the 2x2 or just use 2x3x1/8th for the tongue adding a style supports.

[angib]

use a torsion axle, it will replace an X member.

Actually if you want to build light, a torsion axle isn't ideal - it weighs a lot and the axle tube doesn't do double-duty to support the floor. So on the Pico-Light and other lightweight designs I use half-axles and an axle cross-member that provides floor support.

Andrew

[angib]

for a trailer around 1000 lbs, would 1" tubing be enough around the perimeter and cross pieces?

This is getting too complex to describe in text - we really need to be looking at drawings which can't mean different things to different people.

In general, I think 1" tube would be enough for a body frame and cross-members. However:
- attaching axles to 1" tubes isn't easy (though you could double up the 1" where the axle goes);
- if you are using a single (not A-frame) tongue, then those cross-members need to be stronger, as you've said;
- the length of the tongue and its 'bury' (how much is under the floor) matter - there is no such thing as "this tube is good for any length tongue".

With Rocky's comments about single 2x2x1/8 tongues, we need to bear in mind that I seem to remember his trailer is fairly heavy and it had a hugely long single tongue to start with.

Andrew