Thread: Car Trailer Dolly Q's

Re levelling big frames, I saw on some forum a good idea using clear plastic tube with water in it. I've been meaning to make a manifold so you can have multiple leads. Tape one to each corner or wherever, fill the system with water and you've got a super accurate spirit level.

yeah i done a carpentry course as a teenager and part of it was how to use a water level, but the spirit level is very easy as im only using lengths 4 meters long it doesnt bow from its own weight, i just worked from the highest point than checking all 4 sides and all 4 joining corners and adjusted as needed than squared it off and tacked in all criss cross motion

running out of material but i got down the cross members for both sides,started welding them in place today

one question should i run the center cross members on there sides so so there 50mm high rather than the frame height of 70mm? this way i will have a extra 20mm clearance for the ramps to sneak up under the chassis

Looking good gazza, run the rhs as you planned for more room under for the ramps.
Kryn

jumping a bit ahead of my self here but i have seen pics on google of car trailers running one 1400kg axle, taking into consideration adding drop axles makes the overall cost a fair bit steeper and if i was to run dual drop axles that could be out of my budget

i have a couple questions

could i run one 1400kg axle?

could i run without springs and weld the axle(s) directly to the chassis so no drop axles are needed for lower loading height?

also thinking of selling my motor bike trailer to help fund this new trailer build and i plan on turning this car trailer into a utility trailer with a removable 4x1.9m cage which im sure will only add value

im not entirely sure about my welds i mean im not 100% satisfied my TIG welds will hold possibly a 2000kg vehicle towing 80kph down the freeway, when i go for a registration check im assuming the mechanic probably wont even look at each individual weld on the trailer because he wont be able to see past the paint so how will i know if its structurally sound?

- be careful welding axles.
- drop axles aren't that much more. I think I paid not quite twice a normal axle.
- chop up and look at your test welds. Bash them with a sledgehammer and see if you can break them. Macro etch if you want.
- the inspector won't care about your welds in the slightest. He will care about his checklist, mostly lights, measurements. If you did an overall good job (exterior appearance) he will know fairly quickly. But if in the future something goes wrong your head is on the chopping block. You are registering yourself as the builder and all liability is on you. That's what I was told on here when I asked similar questions.

Originally Posted by gazza2009au

jumping a bit ahead of my self here but i have seen pics on google of car trailers running one 1400kg axle, taking into consideration adding drop axles makes the overall cost a fair bit steeper and if i was to run dual drop axles that could be out of my budget

i have a couple questions

Could i run one 1400kg axle?

could i run without springs and weld the axle(s) directly to the chassis so no drop axles are needed for lower loading height?

also thinking of selling my motor bike trailer to help fund this new trailer build and i plan on turning this car trailer into a utility trailer with a removable 4x1.9m cage which im sure will only add value

im not entirely sure about my welds i mean im not 100% satisfied my TIG welds will hold possibly a 2000kg vehicle towing 80kph down the freeway, when i go for a registration check im assuming the mechanic probably wont even look at each individual weld on the trailer because he wont be able to see past the paint so how will i know if its structurally sound?

Gazza, What do you think. You've basically answered your own question. In a nut shell NO, it would be overloaded.
You could run with out suspension, but what happens to mums fine crystal and china, when it's loaded onto the trailer with the cage, to move her into her retirement home??????? To do that, it would need to be a car trailer only. For the cost of the suspension and axles, I would go full hog as when/if you decide to sell it, you should at least be able to recoup your costs of materials. A lot of people don't like solid suspension on trailers, resulting in a trailer that would be virtually a give away. In SA, a NEW multi axle trailer, must have a load sharing suspension.
Kryn

I must say I haven't been following this thread very closely, but from the sound of it:

1. You're building a car trailer.
2. Which, I assume, you'll want to use to carry a car.
3. You're asking if you can use just a single 1400kg axle, that will ultimately be carrying the weight of trailer + car.
4. You're also wondering if you can do without suspension and connect the axle direct to the chassis.
5. Aaaand you're not really sure how kosher your welds are.

Have I missed anything?

Originally Posted by Legion

- be careful welding axles.
- drop axles aren't that much more. I think I paid not quite twice a normal axle.
- chop up and look at your test welds. Bash them with a sledgehammer and see if you can break them. Macro etch if you want.
- the inspector won't care about your welds in the slightest. He will care about his checklist, mostly lights, measurements. If you did an overall good job (exterior appearance) he will know fairly quickly. But if in the future something goes wrong your head is on the chopping block. You are registering yourself as the builder and all liability is on you. That's what I was told on here when I asked similar questions.

i looked at a local trailer spares company up the coast but there drop axles are over $500 each axle

Originally Posted by KBs PensNmore

Gazza, What do you think. You've basically answered your own question. In a nut shell NO, it would be overloaded.
You could run with out suspension, but what happens to mums fine crystal and china, when it's loaded onto the trailer with the cage, to move her into her retirement home??????? To do that, it would need to be a car trailer only. For the cost of the suspension and axles, I would go full hog as when/if you decide to sell it, you should at least be able to recoup your costs of materials. A lot of people don't like solid suspension on trailers, resulting in a trailer that would be virtually a give away. In SA, a NEW multi axle trailer, must have a load sharing suspension.
Kryn

yeah ill go with suspension mate was just asking

Originally Posted by RustyArc

I must say I haven't been following this thread very closely, but from the sound of it:

1. You're building a car trailer.
2. Which, I assume, you'll want to use to carry a car.
3. You're asking if you can use just a single 1400kg axle, that will ultimately be carrying the weight of trailer + car.
4. You're also wondering if you can do without suspension and connect the axle direct to the chassis.
5. Aaaand you're not really sure how kosher your welds are.

Have I missed anything?

rusty are u trolling or are u implaying i shouldnt be building a trailer because A i dont have a certification in welding and B im not a en-engineer?

ok maybe i should have been more clearer in my previous post as to one axle trailer, since im building this trailer to tow a car i was actually thinking of downgrading my 1970kg Mitsubishi Pajero to something like a Honda HR-V or CRV maybe a Rav4, the honda weighs 1150kg Rav4 1250kg, but in saying that i see im still over the 1400kg axle weight, could i possibly go 50mm axle thats rated 2 ton..

im just checking out my possibilities guys nothing is certain

is drop axle even worth it? my drive way is sloped around 1-1.5m over around 12-14 meters which i never took into consideration if i could even getit up the drive way hmm

Originally Posted by gazza2009au

rusty are u trolling or are u implaying i shouldnt be building a trailer because A i dont have a certification in welding and B im not a en-engineer?

No, I'm not trolling, but I was starting to think you might have been given what I'd summarised. If you were building a box trailer that would rarely be loaded to anything near its weight capacity, these things wouldn't matter so much. However you're talking about a car trailer that will always have a load (a car) that will be right up on or over the rating of the axle, and it's a load that will impose significant stress on all the components of the trailer. That means everything has to be right, there's not the room for error that you get with a general-purpose box trailer.

Furthermore, the suspension in a trailer is not there just to stop the load from being knocked about, it's also there to absorb shocks and impulses of energy that would otherwise be borne by the trailer chassis, the kind of serious forces that would test a weld to its limit and beyond.

No, I don't think you need to be a certified welder or engineer to build this kind of trailer, but you do have to have some idea of how and why things are engineered the way they are. I think you do need to have a good idea of the quality and strength of your welds, and a good understanding of how they fail. If you haven't broken joins and studied how and why they broke, or bisected joins to see what the fusion and penetration is like, then I don't know how you can be confident your welds are good.

Rusty, Kryn worked it out on his computer as to what design to go with so no engineer needed, im happy with my TIG welds its just the MIG welds i done, ground down than re welded over with TIG im not sure about?

i will be keeping the trailer so if it breaks it'll do so on me and not someone else so no liability

and it wont be loaded to its capacity as i hold the heaviest car in my family but im downgrading to a smaller car that'll only see the trailer used at around 50% of its load capacity

If it breaks on the open road and the load goes tumbling down the freeway, liability.

Legion i was planning on welding rated safety chains to the draw bar that would be attached on both front tow hooks for this very reason, but now im maybe just going to build a flat bed trailer for general use ie: motorbikes,moving houses,towing lengths of timber/roofing/metal around and what not i may reinforce certain sections of the trailer for holding specific heavy items like car engines,transmissions,100hp+ outboard engines etc... and to have 4 removable caged sides would be unreal still early stages so i donno where im going just yet

i have been using my 5 meter empty boat trailer for moving the steel around for this trailer build and the galvanised coating is getting a little scratched