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View Full Version : Stub axles and using RHS for the axle



surfin
10th Jun 2010, 03:27 PM
Did a quick search and didn't find anything....


So what is the go with using stub axles and welding heavy wall RHS to make a complete axle for a trailer?

Is it legal?

Not planning on doing it now...but have seen it done and may do it for future projects

Thanks

Craig

jatt
11th Jun 2010, 07:52 AM
On lite trailers used 4 mm RHS for axle. The weld inside 5mm makes it harder to fit

Spent more time making sure the stub was lined up than actually welding it. Wrapped a damp cloth around the threadded end. Recon a bit of preheat where its gunna be welded would be a goer due to the thickness of the bar.

Legal? Assume so.

On bigger/heavy duty trailers solid axles would be better.

BenM78
11th Jun 2010, 01:22 PM
Do the axles actually take any load or are they just there? ie, if you have a stub welded into the RHS, then the spring gets bolted to the area where the stub fits into the RHS then the load is transferred from the wheel to the stub to the spring to the frame, the axle tube doesn't do anything except maintain the straight up and down motion in the spring system? If you know what I mean?

dazzler
11th Jun 2010, 08:56 PM
I am sure that there are states that this is illegal. But for the life of me I cant recall which ones. Before you do it definitely call your local rego people to check as it will get knocked back at rego if its not legal.

The other thing is why bother. Just work out your length and get one from the trailer people.

Yonnee
17th Jun 2010, 03:08 PM
It's quite legal, and is in fact how some axles are still made today. A QLD based company actually make some of their heavier axles this way, and they're an ADR approved manufacturer for over 4500Kg. The trick is to have the stub axle inserted far enough into the tubing so as not to crush the tube with the U-bolts. Also, the stub axle needs to be a pretty neat fit into the tube, again so as not to crush the tube. Once you put a kink into the outer tube, it will dramatically reduce its strength, so it's critical that the correct sized U-bolts, tube and stubs are used.

bobsreturn2003
29th Jun 2010, 06:39 PM
What about welding the stub to the outside of the shs to make a drop axle . As thinking of building a 4x4 trailer , have the wheels and lowering the load - tractor . For stability off road can i do this? Thanks bob

Yonnee
30th Jun 2010, 12:34 PM
Hey Bob.
While it's quite acceptable to have an Overlay axle (stub welded on top of the main beam) or a Drop axle (solid piece welded between beam and stub, usually either 2.5" or 4" centres), it's not something I've seen or would recommend to be done using SHS as the axle beam.

soundman
2nd Jul 2010, 10:15 PM
The main issue I can see here is ensuring the integrity of the job.

A manufactuer with access to an engineer, testing facilities and certified welders...... no problem at all.

But a back yard fabrication...or even an uncertified workshop fabrication and I would have serious reservations.

Remember you the manufactuer of that trailer are responsible for the life of the trailer.

Unless you have " significant engineering resources" I don't think it could be recommended.

Then there is the big question...WHY.

Axles are reasonably cheap and easy to just go and buy.....even if it is weird....most places will supply to order.
And yess overlay axles are easily available straight off the shelf.

cheers

Yonnee
3rd Jul 2010, 12:33 AM
While it pains me to agree with the above, I only do in part.

There is no requirement for any trailer manufacturer to have an engineer, testing facilities or certified welders.

Some "backyard" facilities have better qualified people and better equipped workshops than some commercial businesses.

"WHY?"
Because some of us can!

soundman
3rd Jul 2010, 12:58 PM
there may be no legal requirement but if things get to court and there has been a component failure.

Having proper facilities will be assumed as part of a duty of care, and from an informed insurers point of view.....you would be hesitant to underwrite someone without proper facilities.

Of course there will be those of us, well resourced and skilled in certain areas........but this would be the extreeme minority.



But again it comes down to.....WHY would you.

cheers