My Frame Plan

[TD4FREEW/CTD]

I've been tinkering with paint and i think i have a reasonably sound design, of course, all productive input is appreciated

I'm thinking i want to use 1/8" wall box tubing. i really have no idea what the trailer will weigh but i figure if i go 1/8" it will pretty much be strong enough for anything i could put on a 4'x8' or 5'x10' chassis. all the angle joints will be mitre cut and welding process will be TIG. I will probably rosette weld the steel plate up front, along with welding the perimeter.

[Podunkfla]

It looks good TD4FREEW/CTD... But you prolly don't need the middle tube running all the way with that A frame tongue? And, I doubt you neet the four angle braces in the corners either. A few welded tabs and maybe small corner gussets for mounting would make mounting the floor easier. I'm not picking at ya... Just some humble suggestions.

Doug Hodder's Frame Building Tutorial is about as good as it gets... IMHO: http://www.teardroptrailers.us/dlpage.html

[TD4FREEW/CTD]

I absolutely appreciate your humble suggestions. i usually tend to go a lil overkill with things. i'm actually wondering if i could get away with a 16 or 14 ga wall instead of 1/8". it would probably save me a bunch of moolah.

my corner braces dont need to be the 2x2 box tube as well. it really depends on how much scrap i have left over from the 2 or three 20' sticks i have to buy. if i can find some reasonably long choice rem cuts i may not buy the 20 footers. otherwise a smaller piece of angle or something may be in order. mounting tabs are a good idea

i'm not sure i follow you on the front end. are you suggesting that i have the A come together sooner, or that i dont run the center beam all the way back to the cross member? i do want the tongue to be stout enough to hold a decent bank of batteries and possibly some water and propane.

[Podunkfla]

i'm not sure i follow you on the front end. are you suggesting that i have the A come together sooner, or that i dont run the center beam all the way back to the cross member? i do want the tongue to be stout enough to hold a decent bank of batteries and possibly some water and propane.

Yep... I was just suggesting, as you stated, just having the two sides pieces of the "A" and a shorter tongue reinforced from your metal plate(s)forward? Welding a plate top and bottom at that point would be very strong. And, The "A" triangle is plenty strong enough welded four places to the frame, as you drew it. Of course, there is nothing wrong with the way you designed it. But, more steel does add up to more weight... and it's not hard to end up with a 300 pound frame & axle. Most tears just don't need all that much strength (or weight). Again, just my humble opinion.

[madjack]

TD...here is drawing of the frameI just built...1x2x3/16 "C" channel frame with a 2x1/4 tube f/main tongue tube...if you will click on the "Trailer Tutorial" in the top index, I believe they use 16ga 2" tube.........
madjack

[angib]

Yep, I second Brick - lose the centre tongue tube as it won't do much - the two angled tongue tubes will take all the load.

I don't believe the 1/8" plate on the front does much good and it could be left off with no harm. Ditto the corner braces which don't make the frame any stronger in directions that matter.

Unless you plan to build very light, keeping 2"x2"x1/8"(11ga) for the two tongue tubes would make sense. But for all the rest of the frame, 14ga or 16ga, IF you can successfully weld metal that thin, is perfectly strong enough.

Andrew

[doug hodder]

By using 16ga. tubing over the 1/8" material in 2x2 tube...you'll save almost 1.36# per foot. Based on your design, not counting the tongue, and if it were a 5x10 that would be a nearly 55# weight savings. Pretty significant. Doug

[TD4FREEW/CTD]

talked to my metal supplier today,

2x2 box tube prices are as follows(provided i buy 60'):

16 ga = $2.20/ft
14 ga = $2.63/ft
1/8" = $4.09/ft.

weights/foot are as follows:

16 ga =1.69 lbs/ft
14 ga =2.13 lbs/ft
1/8" =2.94 lbs/ft

i've estimated roughly 45' of tube for my build, thats without the central beam. i've decieded that 1/8" is out of the question. too heavy, too expensive. im only building a light weight trailer, anyhow. so its between 16ga and 14ga. the overkill in me wants to go for the 14. if i go 16 it will cost me $132 plus tax. 14 will be $157. weight would be approx 80 lbs for 16. approx 100 lbs for the 14. the price is negligable to me, and really the 20lbs is too. i wont have problems welding either one. since i will want this trailer to be somewhat capable of going off road, i'm leaning even further toward the 14. i dont want to go romping the trailer like a jeep, i just want to be able to make it to my no mans land campsites (rocky trails (no boulders) with lil hills)

whatchall think?

[angib]

The 14ga will count as 'really light' with most people here, I think. 14ga is about 75% as strong as 11ga(1/8") and 16ga about 55% as strong.

If your tongue is 48" from the front of the frame to the coupler, the Australian trailer rules would limit you to 975lb GVWR for the 14ga and 760lb for the 16ga. I think the evidence here is that it's safe to double these figures for teardrops, which are not abused like utility trailers are.

Andrew

[TD4FREEW/CTD]

The 14ga will count as 'really light' with most people here, I think. 14ga is about 75% as strong as 11ga(1/8") and 16ga about 55% as strong.

If your tongue is 48" from the front of the frame to the coupler, the Australian trailer rules would limit you to 975lb GVWR for the 14ga and 760lb for the 16ga. I think the evidence here is that it's safe to double these figures for teardrops, which are not abused like utility trailers are.

Andrew

so i imagine that rating would go up if the distance of coupler to the frame is shortened (less mechanical action working against it)?

and what if the tongue is made of a stouter material than the frame. is that logical?

[angib]

so i imagine that rating would go up if the distance of coupler to the frame is shortened (less mechanical action working against it)?

That is how the Australian rules work. And it's linear - halve the length of the tongue and you double the maximum weight of the trailer, if all other things are kept the same.

and what if the tongue is made of a stouter material than the frame. is that logical?

I believe strongly that this is so. It seems that only tongues ever fail.

On a teardrop, which has a body that is very strong in its own right, I would say that on a frame design such as yours, a tongue section twice as strong as the frame section is sensible, though obviously it's inconvenient to have to buy two sections.

Andrew

[Esteban]

I don't see that Andrew has sent you a link to his Tongue Strength design information. It's full of good information and well worth printing out to use as a design reference. It's available up above in the Design Library or by clicking this: Tongue Strength

I'm designing my frame too. Trying to keep it as light as reasonably possible with a strong enough tongue. I'm going back and forth between using an A Frame or a Composite Frame - like your design above. I'm designing a 5'x 10' teardrop and am hard pressed to keep it's weight low as my tow vehicle has only a 1500 lb. capacity. In ballpark figures the frame, axle, tires, and jacks will weigh 350-400 lbs. The wood floor, sides, and roof/hatch will weigh another 400 lbs. or so. Aluminum skins and trim, cabinets, windows, the battery and electrical system will add some more hundreds of lbs. An empty 5'x10' teardrop may easily weigh around 1100-1200 lbs. which does not leave much capacity, in my case, for bedding, a stove, an ice chest, food, ice, drinks, water, chairs, an Easy Up, and other personal camping stuff. Not trying to thread jack, but to interject that if you build a 5'x 10' you'd need to design for a tongue with a strength well over 1500 lbs. according to the Aussie tongue strength rules.

[McTeardrops]

I believe I would stay with 1/8" wall for the tongue. Also you might want to measure some tongue jacks, to make sure you have enough room to swing up to store.

[Alphacarina]

Assuming you can weld it all without any problems, get one 20' stick of 14 gauge for the tongue and the front crosspiece and then 2 sticks of 16 gauge for the remainder of the frame

Don

[TD4FREEW/CTD]

Assuming you can weld it all without any problems, get one 20' stick of 14 gauge for the tongue and the front crosspiece and then 2 sticks of 16 gauge for the remainder of the frame

Don

Duh! I cant believe i didnt think to ask the guy if the prices were still reduced if i bought the same length of different materials. thats a good idea.