Building Your Own Trailer

[Craig Best]

Hi I'm new here, looking for info on building a box trailer in QLD.

Looking at 7x4 and ATM less than 750kg.

I'm an okay welder and handy with power tools and back in my teens, many moons ago I built a tiny 4x3 trailer to tow behind a Leyland Mini Moke.
Actually used the sub frame from a Moke as a starting point and built a frame over the top using the mounting points. So it shared the same wheels, all legally registered and was pretty nice job.

Anyway my current 7x4 has seen better days and has some bad rust underneath, dad got it about 25 years ago 2nd hand and its been a job to keep it together.
This one weighs about 300kg as it stands wth a cage.

So I'm considering building one from scratch but need to know the rules and what is required.
I do plan on getting new wheels and hubs, and anything else needed.

My basic plan it square tubes for the base and drawbar, but the sticking point it the side material.
I want it as lite as possible because it will be towed with a mid size car.
I do plan on adding a cage so it will be about 90cm tall from the floor, and rails on top for carting 8x4 sheets of plywood.

Any advice or help would be great.

[pop058]

Use RHS ( as opposed to SHS) for your main frame and drawbar.

[Slunnie]

For the corners we use 50x50 RHS on box trailers, and the sides you can do from Hot rolled sheet and fold the top over at 50mm and again at 50mm which prevents it from bowing out. We do them at 1.6mm, but your call on how think you want to risk.

I'm not sure if you follow the NCOP VSB1 in QLD, but here are those rules - its a pretty safe guide at the very least:
Vehicle Standards Bulletin VSB1 (https://www.infrastructure.gov.au/vehicles/vehicle_regulation/bulletin/vsb1/index.aspx)

[Craig Best]

Thanks for the replies, this is still in the planning stage.

I basically have 3 options.

Repair the current trailer, which will involve striping it and accessing the damage, this could be the cheapest option but may involve replacing some of the frame. So this info still helps.

Built from new, more expensive and time consuming.

Easy option is you just buy something else but given the price some are after for rusty old ones it would probably be something new.

[Slunnie]

You know, to be honest here, for small trailers like what you are after, you cant do better than Chinese imported trailers.

Chinese trailers are built as lightly and cheaply as they possibly can be. They're imported in containers and have the drawer bars welded or bolted on locally.

We build loads of trailers and for a small trailers, the cost of materials, parts and finishing only (no labour or GST) is not close to what a Chinese trailer can be bought for. Mind you, our trailers are far better in strength, they have better components and are better finished but also twice the cost. When you get into medium sized trailers it is cheaper to make them than to buy them and large trailers you can build them for about 50% purchase price.

[Don 130]

You can get the sides already folded to shape.

TBPK - Trailer Body Panel Kits - 6x4 to 8x5 - NO FLOOR & NO GUARDS- DIY Trailer Kits Australia (https://diytrailerkits.com.au/product/bk6x4-trailer-body-kit-6-x-4-320mm-high-zinc-panels/)

Don.

[DoubleChevron]

get an old caravan or caravan chassis and use the chassis as your trailer base. That way you should end up with at least a 1200kg spring pack, 1.5'ish ton drop axle, brakes, decent frame .... You build the box on top. A super strong safe trailer with brakes.

All the trailers these day are lightly made chinese crap. The local trailer place here has "locally made" trailers. You see them in there yard. They are imported complete without axles fitted as parts. They will be imported as "parts" do they probably save a lot in taxes etc... They then "build" the trailer by bolting the axle on ... [bighmmm] It will make importation much cheaper as you can fit a huge number of trailers stacked into a container if you don't fit the axles.

The drawbars on some of the trailers look big and substantial until you climb under and look ... the will thickness is "nothing"..... Looks to be about 0.8mm wall thickness :o

seeya,
Shane L.

[101RRS]

Sounds like you need a basic box trailer - nothing special.

Why not just buy a good second hand one. They are out there reasonably cheap if you are patient.

I had an old 6x4 box trailer that was OK but nothing special. When I bought my Haflinger I decided I needed a trailer that I could carry it and also use it for all the other things you use a basic trailer for.

After a couple on months looking I found a good rust free 8x5 on Gumtree for $700 and bought it - I then sold my old trailer for $300 so a change over of only $400 - is a lot cheaper than trying to build from scratch. and you dont have the issue of trying to deal with authorities to get a VIN/Chassis number for a home built - easy in some states, hard in others.

Garry

[DoubleChevron]

You know, to be honest here, for small trailers like what you are after, you cant do better than Chinese imported trailers.

Chinese trailers are built as lightly and cheaply as they possibly can be. They're imported in containers and have the drawer bars welded or bolted on locally.

We build loads of trailers and for a small trailers, the cost of materials, parts and finishing only (no labour or GST) is not close to what a Chinese trailer can be bought for. Mind you, our trailers are far better in strength, they have better components and are better finished but also twice the cost. When you get into medium sized trailers it is cheaper to make them than to buy them and large trailers you can build them for about 50% purchase price.

This is interesting. I thought the chinese larger trailers would be way cheaper than building them yourself. Just pricing a twin axle kits with wheels and brakes will set you back a couple of grand .... Then there is the eye watering price of metal from the local metal merchants!

I have no doubt you are right though. I've always been surprised by how expensive trailers are (for what they are).

seeya,
Shane L.

[DiscoMick]

We bought one of these and are very happy with it, so that might give you a comparison.
Ours has a cage and optional larger wheels.

Box Trailer Brisbane QLD | Trailers For Sale Australia | Tandem Trailers (https://lhtrailers.com.au/)

[Slunnie]

This is interesting. I thought the chinese larger trailers would be way cheaper than building them yourself. Just pricing a twin axle kits with wheels and brakes will set you back a couple of grand .... Then there is the eye watering price of metal from the local metal merchants!

I have no doubt you are right though. I've always been surprised by how expensive trailers are (for what they are).

seeya,
Shane L.

Actually Shane you may be right there...

For small trailers we are really comparing to imports which is what the market is all about, but most of the big stuff we are comparing to is Aus made. When I'm talking big, we're normally talking things like tandem enclosed, 2.4mx5mish table tops and tippers, horse floats etc which are not normally imported I don't think, So for example a $20k horse float would cost us about $9k to build, a $20k 3 way tipper costs us about $10k to build etc. I wont go into brands, because as a school the companys are really good to us in terms of supply and sometimes supply us with proprietry components where they normally wouldn't. Most of the cost is in the components and the finish for us. 3.2T tandem rolling component setups cost about $2600 and interestingly a 4.5T triple is about the same cost. Powdercoat can be up to about $2k but depends on the surface area. Aussie trailer manufacturers are very slick operations with their production and the products are good, especially Dean Trailers, but you're still looking at one off and batch production processes done by tradies. Mind you, the industry is going through a period of development right now and there is investment in plasma and laser which has certainly changed ute tray manufacturing in terms of speed, cost and quality, so it will be interesting to see if that somehow migrates across to trailer manufacture, and I suspect it will.

[Gordie]

For a fairly basic welder like myself, I would find it easier to 'rebuild' an old trailer, than start from scratch, at least you have something to work with and you are just taking out and adding in bits and peices.

As to the chinese trailers, I went through it all here in NZ a while back, I was after a tandem galv cage trailer, the locally built ones are far superior in build quality and I dare say longevity, but are roughly twice the price. I ended up with a NZ made one, as I factored in the extra price and divided it by the 30yrs or so that I will have it, and it wasn't that much more if you looked at it that way.

My parents have a chinese one, and it serves its purpose, but after about 5yrs of very light use, you can tell that it isn't going to be as long a lasting trailer.

Some outfits here get them made in China, and assemble them here to their specs, ie decent stubs and bearings etc, and weld together, not bolt. Those trailers seem a reasonable option too, as they are not quite as cheap as the Chinese proper, but not as expensive as the NZ made.