Trailer construction - Welding joints advise.

[dieseldude]

I'm about to start making another trailer over the Xmas break to carry my motorbikes - and to be suitable for outback trips over rough roads.

I've made a 3 bike trailer previously but feel that I can do a much better job. Therefor, this time I'm doing a lot more planning in the design of the trailer for strength and simplicity.

What I'd like to know is:
- Can I benefit from using 'half lap joints' with RHS steel sections (the same as wood workers use)? The reason for this is because I want to run a draw bar the entire length of the trailer. To keep the floor of the trailer on the same plane as the cross members, I'm going to either have to notch both sections, or butt weld the cross members off the draw bar. Would cutting through both members partially, so that they slide together and then be welded up - be stronger than totally cutting through one section (cross member) then having to butt weld to the draw bar?

Any help in this regard would be greatly appreciated.

Regards

Anthony.

[benhl]

speak to bubs - he good at weldin sh1t!

[dieseldude]

Yeah, I was going to wait and see if he replied to this.

Hopefully someone in the industry could tell me the correct way to go about this. I'd hate to see my drawbar etc snap off the trailer from corrugations in the middle of nowhere. (I saw plenty of wrecked trailers around Cordillo Downs just recently).

I've read previously that you shouldn't weld on the horizontal surfaces of a drawbar (presumably where the cross bars sit adjacent to the draw bar) because this creates a weak point and is likely to snap at that point.

Can anyone shed some light on this at all?

Also, any other design hints would be greatly appreciated.

Regards

Anthony

[dieseldude]

The design of the trailer at present is somewhere along the lines of:

* Split rims to suit those on my 100 series crusier
* 7.50 r 16 MRF super traction tyres - also to match my cruiser on outback trips
* Beam axle with shackle leaf suspension
* Box section recessed vertically into each of the 4 corners to allow changing of frames for the dual purpose role of motorbike / camper trailer. If you imagine a flat trailer with only floor and guards, this is how it will look with neither of the frames attached. The first frame will have smaller rhs to slide into the two front box sections recessed in the front corners. This frame will go across the front to hold the front wheels of 3 motorbikes. The second frame will ideally enable the trailer to operate as a high sided box trailer with rear tailgate kitchen to which a canvas camper top will be fitted. (If that makes sense.........)
* Across the front of the drawbar will be a storage box with jerry can holders
* Behind the rear guards will house a gas bottle arrangement.
* Water tank underneath plumbed to a manual hand pump.

More to come as I start building it. No doubt certain details will change with time.

I hope to have this all welded up in my 2 week break over Xmas. We shall see......

Regards

Anthony.

[chook05]

What help do you need with joints? opps sorry wrong joints

[dieseldude]

Ha ha, Nice!

[STIKA]

why don't you want to use an a frame draw bar that stops just in front of the front of the spring mount

[STIKA]

why don't you want to use an "A" frame draw bar that stops just in front of the front of the spring mount

[dieseldude]

why don't you want to use an "A" frame draw bar that stops just in front of the front of the spring mount

I am using an 'A' frame draw bar. For piece of mind, I'd like to have one main member which runs the length of the trailer. It might be an overkill, but considering some of the places I'm likely to be travelling, I'd rather not have to deal with fatigue on two pieces of RHS when I could have improved the design to begin with...........

I guess - just consider it an 'A' frame with one long length straight down the guts to the rear cross member.

[chook05]

Ha ha, Nice!

made you change the subject wording pretty quick. ha ha

[Nelso]

If you weld with full penetration, a full butt weld is as strong as the steal that you're welding. It depends on how well you can weld and the power of the machine you are using.

[v840]

If you weld with full penetration, a full butt weld is as strong as the steal that you're welding. It depends on how well you can weld and the power of the machine you are using.

True, but its hard to tell if you have full penetration along the entire length of the weld. Particularly if he isnt experienced. If it was me Id want some sort of reinforcement rather than relying on weld strength alone.

[rover1]

If you weld with full penetration, a full butt weld is as strong as the steal that you're welding. It depends on how well you can weld and the power of the machine you are using.

True, but its hard to tell if you have full penetration along the entire length of the weld. Particularly if he isnt experienced. If it was me Id want some sort of reinforcement rather than relying on weld strength alone.

just grind a 45deg weld prep on the 2 sides of the rhs that you will butt join. than weld them with a root run first, than go over it and fill in the rest. you will get full peno without grinding the top and bottom, the rhs will have rounded coners, and you will most likely have trouble welding them in 1 run, if you dont know much about welding.

[Lorenz]

I'm really interested in welding, I own a welder but don't really know how to weld. Can you post phtos on your progress when you get started?

[dieseldude]

Yeah,

I'm happy to post some photos when I get it started - No worries at all.

In terms of my welds.................. I'm fairly confident that I can achieve decent welds. I'm in no way qualified etc, but from various items/ trailers etc that I've built in the past - I've never had a weld fail yet.

So, back to my initial question.................... Does using a 'half lap joint' effect the integrity of the steel in any way compared to butt joining members? Can anyone see any adverse effects in doing this?

I guess that I'm more inclined to use pieces of steel which are still the one continuous length for piece of mind (albeit they might be notched slightly where the joints are....)

Any comments on this?

Cheers

[dieseldude]

By the way - I'll be burning it all together with a CIG stick welder (not sure of the amperage and all of the rest of the imformation).

I used this welder for my last trailer and it went great guns.

Cheers

[bru21]

don't notch the draw bar. butt weld the cross bars. Ideally the draw bar steel will be thicker to lessen the point loading of the cross bars - hence lessen the stress concentration. also make the draw bar out of a bigger section and have the cross members attach to the side at the top so the base of the draw bar is not welded to to help in the compression bending moment the bar receives. normally only 2 of the 4 sides of the crossmembers (top and bottom) are welded this is better still (less stress concentration in the draw bar), however if you are not 100% confident in your welding weld all 4 sides.

use ford axles as they have bigger bearings (either in ford or holden or l/c pattern ie ford axles are available in all stud patterns)

also the shackle style springs are better as they don't wear through the trailer.

the sad part about building trailers is that the running gear is like $500 plus for good stuff (without steel) makes it hard to justify - unless you want something for the cape etc.

cheers bru

[dieseldude]

I used Ford bearings on my last trailer. Had one fail - but that's not to say that anything isn't indestructible.

Is there another step up from Ford bearing hubs? What do manufacturers of say Kimberly Kampers etc use on their trailers?

I'll certainly be using shackle suspension for this one. My last trailer used slipper springs and I'm not a fan of them at all.

Cheers

[phippsy]

80lsy off here has built a couple of car trailers, might be worth dropping him a pm.

[STIKA]

Talk to the guys at Active Fabrication at Beenleigh, they are by far the cheapest around and offer great advice on all trailer componants

My car trailer cost me $3k on the road thats with largest bearing available in a land cruiser configeration and orbital eye suspension and 4 x 11 inch brakes. and all steel, other trailer parts suppliers were quoting $3k+ for the componantary

If you are looking a doing dirt/off road work i would recomend that you also fit brakes, if you have to stop in a hurry the more brakes the better

[STIKA]

I would go with the butt jointing, less to weld, especially if you are using a stick welder.

[dieseldude]

Yeah, Active Fabrications are good blokes. I've purchased guards off them previously and couldn't be happier with their service.

They'll be getting used for this project no doubt.

[stinger]

I would not use Active Fabrications for any parts again. I rang them up to inquire what time they closed. I arrived 10-15 mins before closing time and was refused service. I had driven down from Brisbane, rang on route to make certain I would be there before they closed and not right on closing time. I knew what I was after, two axle stubs and two hubs, nothing difficult. I advised I had driven down from Brisbane and was RUDELY REFUSED service. So f**k em when to Super cheap who have reduced their prices and not to much different.

My brother was with me at the time and was shocked at the response I was given and he is from Melbourne.....

[Guy]

Can you use the stub axle/hub/bearings from a hundred series so you get the big bearings used in the front end of your truck and interchangeable parts (IE bearings and rims) with your vehicle ...

I have seen em used as mounts for spare tyres before on swing away tyre carriers ...


Is there any serious issues with this sort of setup I may be gloriously ignorant of ?

[STIKA]

from memory i think the hubs/bearing are the same as a ford courier and they come in landcruiser 5 and 6 stud configeration.


your bearing and axle tubes give your load rating the courier bearings do give a greater load rating

[STIKA]

I would not use Active Fabrications for any parts again. I rang them up to inquire what time they closed. I arrived 10-15 mins before closing time and was refused service. I had driven down from Brisbane, rang on route to make certain I would be there before they closed and not right on closing time. I knew what I was after, two axle stubs and two hubs, nothing difficult. I advised I had driven down from Brisbane and was RUDELY REFUSED service. So f**k em when to Super cheap who have reduced their prices and not to much different.

My brother was with me at the time and was shocked at the response I was given and he is from Melbourne.....

Sorry to hear you were treated that way

Between my brother and my self we have built 2 x campertrailers, 1 x box trailer, 1 x caravan, 1 x car trailer. the only problem i have had was a faulty jockey wheel, which they promptly replaced.

[claud]

the strongest type of weld ive read is arc ,they use it on aircraft engine mounts ,so thats a lot of torque to hold down. the bigger the amps the bigger rods and metal size thickness u can weld go big and do overlap corner sections that run 4 inches or so if u really wanna be sure add a few big bolts.what the hell its another spot u can attach the second top from.like jack stand set ups with pins.
as for yr q. on how to lap steel;
by cutting overlaps in your sections u weaken the size strenght.your in effect halving the steel size,too many corners fold and can collapse keep welds straight and thick.if u get poor welds stop and angle grind clean the weld surfaces. any deposits will blemish the smooth weld run.
i studied structural engineering .but im not a qual. welder.

[ISUZUROVER]

Can you use the stub axle/hub/bearings from a hundred series so you get the big bearings used in the front end of your truck and interchangeable parts (IE bearings and rims) with your vehicle ...

I have seen em used as mounts for spare tyres before on swing away tyre carriers ...


Is there any serious issues with this sort of setup I may be gloriously ignorant of ?

I was thinking the same - many people have built 4x4 trailers this way. 4x4 bolt-on stub axles and hubs. A lot of unsprung weight, but huge bearings and lots of strength.

[dieseldude]

Can you use the stub axle/hub/bearings from a hundred series so you get the big bearings used in the front end of your truck and interchangeable parts (IE bearings and rims) with your vehicle ...

I have seen em used as mounts for spare tyres before on swing away tyre carriers ...


Is there any serious issues with this sort of setup I may be gloriously ignorant of ?

I was thinking the same - many people have built 4x4 trailers this way. 4x4 bolt-on stub axles and hubs. A lot of unsprung weight, but huge bearings and lots of strength.

So does this mean that I measure the hub on say the front of my cruiser, go to the engineering shop (I know of a local trailer component manufacturer), and get the tapers on a heavy duty axle spun up to match to match these bearings?

I think I'd be far more confident in using a 100 series hub with their bearings compared to the off the shelf 'Supercheap' hubs (which I've used in the past).

Has anyone got any clarification about this? It'd be greatly appreciated.

Cheers.

[dieseldude]

Any more thoughts?