what tube to use

[matt mg410]

about to nock up full external roll cage need to no what tube is the most common to be used. is mild steel the go (easy to work with but heavy) or is something out there a bit better.

[small talk]

Also would like to know this for when i build my exo.

[Spike_Sierra]

42mm OD 3m thick i think is about right

[Gutless]

32 NB ( Nominal Bore) is about 44 mm in Dia. use Medium tube, which is about 3.2mm wall thickness. Great for zukes.

[christover1]

If you wish to compete in any offical comps, then best to get this info from the rules book/s.
Would be a bugger building something you can't use.
If it's for other uses, then go by what the experienced members say.

christover

[mud4b]

as gutless said but i also used some 4mm wall thickness too..

[Damo]

Has anyone used 32nb pipe & had the cage passed by Qld Dept. of Transport?

The code of practice states 45mm dia with 2.5mm wall should be used. It would be really f*cked if you couldn't get away with 32nb.

[DeWsE]

I thought pipe was not acceptable. So mild steel/black steel shouldn't be used.

[sierrajim]

also be sure to mount the cage in a manner that complies with the comp specs.

You may not wish to do any comp work now, however with so many tracks closing down to public access you may want to in the future.

[DeWsE]

Anyone got the specific rules that are used?

[Damo]

I thought pipe was not acceptable. So mild steel/black steel shouldn't be used.

The code of practice doesn't say that you can or cannot use pipe as opposed to tube. As long as the material is manufactured to the appropriate Australian Standard then it's OK. Your supplier should be able to tell you if the material they are selling meets the standard.

NB: I can't remember what the standard is, i'll post it up when I find it.

[christover1]

Anyone got the specific rules that are used?

this may be a good starting point?

http://www.ozrock4x4.com/Rules.htm

[sierrajim]

the CCDA website would be the best one to work off i would think.

[Damo]

Anyone got the specific rules that are used?

ccda.4wd.org.au

I just checked there trying to find an updated copy of the rules, but couldn't seem to find one. I do remember reading they have a new draft waiting for checking by an engineer but I don't know if that is true or not.

I do have a copy that I downloaded some time back and it states:

Occupant protection: Specification for material and mounting of roll bar
protection shall conform to the respective Vehicle Statutory Regulations for
vehicles registered in the following State or Territory:
· Australian Capital Territory:
· New South Wales: RTA Code of Practice for Modified Vehicles, Occupant
Seating and Protection. Ref. 3.6.10.
· Northern Territory;
· Queensland:
· South Australia:
· Tasmania:
· Victoria: VicRoads Vehicle Standards Information Ref. 28.
· West Australia:

Whether or not this is still the case I do not know.

As for what the state rules are, from memory vehicles under 1000kg can use 75mm x 100mm plates (not sure what thickness, I think it's 4mm), and over 1000kg have to use 100mm x 100mm plates of the same thickness. You have to sandwhich the body panel with a plate on each side joined with grade 8 bolts (I think the minimum is 2 but can't remember 100%). It also says that if the plates are to bolt through a hollow body section then crush sleeves must be used.

Remember, all this is from the top of my head, i'll post up the details when I can.

[DeWsE]

I would start with ozrock, but this is not what is going to be run next year nor is it what will comply with werock from what i understand. From what I have read here werock does not allow pipe, the oz rock rules read:

2.15.4: Round steel tubing (D.O.M Preferred) 1.5â€

[Damo]

[quote="DeWsE"]
2.15.4: Round steel tubing (D.O.M Preferred) 1.5â€

[Damo]

OK, a clarification on what I posted earlier. Remember, this is the code of practice in Qld, other states may be different. Some of this is summarised, some is word for word, but it's all "by the book"

Mounting plates must be aluminium or steel and must have a minimum thickness of 6mm.

Main hoop mounting plates must be at least 100x75 for vehicles less than 1150kg and 100x10 for vehicles greater than 1150kg.

At least 2 grade 8.8 high tensile bolts of 10mm diameter are required at each mounting point.

Steel
------
Main hoop: 45mm dia, 2.5mm wall
Rear braces (straight): 30mm dia, 2.5mm wall
Rear braces (bent): 45mm dia, 1.5mm wall

Aluminium
------------
Main hoop: 45mm dia, 3mm wall
Rear braces (straight): 38mm dia, 2.5mm wall

Twin tube hoops (steel)
---------------------------
Main hoop:33mm dia, 2.5mm wall
Rear braces (straight): 33mm dia, 2.5mm wall

Steel tubes shall comply with the requirements of Australian Standard 1163 1981 - "Circular and non circular steel tubes for mechanical and general engineering purposes".

Aluminium alloy tubes shall be either alloy B6351T5 or B6061T6 and shall comply with the requirements of Australian Standard 1867 1976 - "Alloy drawn tubes".

All welds are to be full penetration butt welds and should comply to Australian Standard 1554 Part 1 1985 - structural steel welding code Category SP or AS 1665 1976 - aluminium welding code.

[matt mg410]

sorry bit late in the piece i know but, i found this www.dotrs.gov.au/transreg/vsb/vsb_ncop_downloads.aspx#7 which states the main hoop must be made of 45mm 2.5 wall thickness so i will make the entire cage out of this. what is the difference between pipe and tube. also my cage will be external so the main hoop and rear stays will be welded onto a custom steel tray which is bolted to the chassis with one m14 high tensile bolt on each corner with crush tube welded in the chassis. the front section of the cage will be welded to sill bars wich will be welded direct to the chassis. will this setup get me into comps or not?

[Gwagensteve]

Maatt,

Most of the comments being made here apply to internal cages, but as you are making an external cage, for the purposes of legality it is NOT a roll cage. It will need to be manufactured along the lines of a roof rack in relation to radiuses/protruding edges etc.

As such, all of the guidlines to foot plates, material mounts etc do not apply.

However, there seems to be no agreement amongst competition sanctioning bodies as to whether an exo is permissable and how it needs to be constructed.

Bear in mind that an exo is much harder to biuld with the same strength as an internal cage as all of the spans are much bigger and the distance from the mounting points is much larger. Also, they often end up very bulky as people try to keep them far enough away from the body to stop rubbing and have some spring before body damage ocurrs.

In relation to tube diameter and wall, I would pay very little attention to most rulebooks unless you are specifically biulding for a comp. I have built cages out of 2.4mm wt 44mm OD DOM and I think this is plenty heavy enough for a sierra. A sierra is a light car and it is best to try and keep it that way to keep it performing ahead of bigger heavier cars.

In a hard roll with an exo or an internal cage, the body will get trashed anyway so consider the cage to have done its job and throw it in the bin. In the case of flops and lean overs, a fairy light cage will do the job and in the case of an exo, it only really has to support the weight of the car.

to build an exo to protect the body entirely from a hard roll would take so much tube and mounting effort that the GOG would go way up and you would roll far more often (and much harder) than if you had nothing at all.