What size steel tubes should I use for the trailer chassis?

[Olympicknight]

Hi ladies and gents,

I am planning and designing to build a travel trailer for a family of four. Approximate size of the living area: 5'6" wide, height 6'3", and length 18'. My goal is to keep total weight of the entire trailer with cargo below 2500-2800 lbs. However, I prefer chassis capable of supporting 3500 - 4000 lbs. I am designing for tandem axle; if weight is too low, I may downgrade to single axle. I am planning to have the trailer chassis with side beams and tongue beams as one piece as noted in the attached picture. See red circled area in the picture. By design, I prefer chassis to be strong enough to protect the cabin from flex, shear, and torsion etc. The cabin will have aluminum studs and skin, foam for insulation, and as little wood as possible. It will resemble a metal tent on wheels. I will have a professional welder weld the trailer main frame and install axles. Not want to build a tank; prefer to go lightweight (like airplane).
Based on following information, what size steel rectangular tubes should I use for the trailer chassis?

From an online vendor, I am getting following price and weight for four pieces of 24 feet long rectangular tubes. I anticipate I will use at least three of these studs.
4 X 2 X 14 GA (.083 wall) 314 lbs for $348
3 X 2 X 11GA (.120 wall) 374 lbs for $412
4 X 2 X 11 GA (.120 wall) 440 lbs for $452
6 X 2 X 11Ga (.120 wall) 620 lbs for $669
8 x 3 x 11GA (.125 wall) 866 lbs for $1,038
10 x 3 x 11GA (.120"" wall) 1028.16 lbs for $1,542

Thank you for your help.

[John61CT]

angle, channel, tube or i-beam?

what sort of total weight loads?

[Olympicknight]

My goal is to keep total weight of the entire trailer with cargo below 2500-2800 lbs. However, I prefer chassis capable of supporting 3500 - 4000 lbs. I prefer to use rectangular steel tubes.

[saltydawg]

You really need to check the prices and weights. This is the price i got and I pick it tomorrow so its recent. I dont have weight, but it should be under 400 lbs total for the whole order but not all is for the frame. 11 and 14 gauge. ANd any drops off full lengths are mine, as I am being charged for full lenghts

weights here, does not have em all but you should be able to extrapolate

https://www.omegasteel.com/pdf/weight-per-foot.pdf

better one

https://www.tubularsteel.com/docs/Squar ... hedule.pdf


1.0 TUBE RECT 3 x 2 x 11GA WALL 24' $59.20 3.8 lbs per foot
Order Line Notes: PLEASE CUT INOT 10 FOOT SECTIONS

1.0 TUBE RECT 3 x 2 x 14GA WALL 24 $44.80 each total for 3 134.40 2.8 lbs per foot
Order Line Notes: PLEASE CUT 2 10 foot PIECES AND SIX 6 FOOT

1.0 TUBE SQ 1 x 24' 14GA WALL $16.08 each 3 pieces total 48.24 1 lb a foot
Order Line Notes: CUT 12 - 6 FOOT PIECES

1.0 ANG HR 1-1/2 x 1-1/2 x 1/8 20 $14.25 each 2 pieces total 28.50 should be about 1.2 lbs a foot
Order Line Notes: CUT 4 - 10 FOOT PIECES

SUB-TOTAL:
Total Lines: 4 270.34
16.21
TAX:
:
AMOUNT TENDERED 0.00
286.55

[bdosborn]

http://tnttt.com//viewtopic.php?t=13765
Bruce

[John61CT]

11GA is 1/8" is that right?

[MtnDon]

for steel, yes.

not exact, but close enough

http://www.metaltrone.com/metalgauge-chart.pdf

brass & copper also differ