Defender 90 Truck Cab Rollcage? DIY?

[Robbiellewellyn]

I am thinking of making my own rollcage with some scaffolding and a hydraulic pipe bender however just need some specifications to get the right lengths and stuff. Anyone know the right angles and lengths that i need or a diagram that shows it all. Cheers in advance.
Rob

[Xtremeteam]

im gonna go first & say No to scaffolding,its no use for making a rollcage out of, have a look here cos its allready been discussed roll cage materials

[beast5680]

good grief another scaffolder :lol:  as has been said read the previous post first as its not a good idea to use scaffolding tube

[bezzabsa]

scpffold doesnt have the correct tensile strength, especially when its been bent!
cold drawn steel 3mm wall.. if in doubt checkout the #a 4x4 is born' dvd, shows you how he made his.. and the cockups he did as well.
if yo uvalue your life, and that of your passengers save up for a professional jobbie..would you have a go at making your own brakes??

[Xtremeteam]

would you have a go at making your own brakes??

brakes or brake pipes? im happy to do any brake work

[bezzabsa]

shhhhhh trying to make a point!
;)
ok would you make your own crash helmets.. i'm a biker see...

[Henry Webster]

The series of pics in Mike's link above show an example of how big an accident you can have at low speed this was at a play day and the vehicle was stationary before it crashed!

If you are going to do it - do it right!

H

[Wolfie]

As others have said, don't even consider scaffold tube it isn't the right material to use.

Have a look at the ARC roll bar regs at http://www.the-arc.co.uk/new%20regulations/rbindex.htm for an idea what is involved in making one. <edited to add> These regs look old, and have a lower material spec than in the current MSA regs.

Regards

Wolfie

[rollazuki]

'Ere we go again, anyone know the specs for scaffold, or blueband tubing????????????????/

[rollazuki]

I say give it a go. Buy some tube(dont get scaffold, and if you do, tell'em its something else.)
Its cheap enuf to use electrically welded tube, or DOM of you want to spend a bit more, but then your pipe bender wont work.
You will need pipe cos it comes in the right sizes for the bender.
buy some spare and practice, its fairly easy to fathom how much material you need for excess in the bends etc.
I found packing the pipe with pea gravel helped the crappy pipe bender do its job without buckling the pipe.
Practice away, then create your cage. I fail to see how you can make a cage that is more dangerous than having no cage(unless yr a complete F*%kwit.  lol)
Its great if you have some cash and can go out and buy a cage, but I tell ya, I feel a lot safer in my zook with my home made cage, than with just the soft top for safety.

[Wolfie]

'Ere we go again, anyone know the specs for scaffold, or blueband tubing????????????????/

http://www.temporaryworks.info/bsicen.htm provides the following information :"BS EN 39:2001 Loose steel tube for tube and coupler scaffolds.
This standard introduced for the first time in the UK the thin walled (3.2mm thickness) scaffold tube as a British Standard scaffold tube.
The BS EN 39 gives details of both Type 3 (3.2mm) and Type 4 (4mm) tube and has the significant technical change that “tubes will now be supplied galvanised, unless ordered otherwise”. It increases the yield stress of tube to 235 N/mm² 18pp ISBN No: 0 580 37960 4"

The "Blue Book" (the MSA one, not the other one  :)  ) states the minimum Yield Strength for tube used for a roll bar is 350 N/mm².

It's up to you, but I know what I want above my head on the weekend of 8th April when I'll be learning how to drive a LR fast off road.

Regards

Wolfie

[rollazuki]

Thanks wolfie, Ive searched high and low for the metal stats.

Finally looks like the scaffold is slightly lower spec.
Its cheap enough to buy pipe from a steel stockholders in the right spec tho, so amateur cage builders shouldnt be put off.

I still stand by what I said tho, that a cage made from scaffold would be tougher than an ally Landy roof.

Most folk arent going to hit high speed off road, but even if they were, what would you prefer, ally roof, or scaffold?

Sensible advice is buy expensive cage, If you dont have the cash, Id go home build.

[Eeyore]

I still stand by what I said tho, that a cage made from scaffold would be tougher than an ally Landy roof.

Most folk arent going to hit high speed off road, but even if they were, what would you prefer, ally roof, or scaffold?
Sensible advice is buy expensive cage, If you dont have the cash, Id go home build.

Oh, I don't think anyone is critising the concept of home build - under the caveat that someone is capable of good welding - just that if you do, use the right materials.

cheers
 8)
Eeyore

[Henry Webster]

Excellent, I am glad to see that this is becoming an educated debate.  I am not qualified to talk about steel specs so I won't, but I have seen enough rolled vehicles to have an opinion on roll cage design and build.

Rollazuki - you say:

Most folk arent going to hit high speed off road, but even if they were, what would you prefer, ally roof, or scaffold?

Agreed, but if you look at the example highlighted above you can see that you can have a BIG accident at low speeds.  This accident took place on a play day and from what I know started out from near standstill.

http://www.olrg.org.uk/daan_off/1.html

There is much more to cage design than purely materials and good quality welding.  Deformability is built into rally cages (where the liklihood is for a high speed accident) but not necessarily into your average challenge/ trial cage.

Cages are difficult things to get right for the amateur - I know, we've tried - and I think it is usually worth buying in some expertise.  Additionally if you are going to the lengths of installing a roll cage why not build it to MSA specs, which opens the possiblilty out to entering comeptitions.  It might help resale values if it is to competition spec and someone else has done the hard work of researching the sensible specs for building.

H

[bigant]

i get my mate martin to make my cages hes a welder so they dont fall apart dont know what type of steal he use's i'll have to ask him but we managed to test one of his cages well when a landy droped down a 20 foot cliff and landed on its roof the engine fell off its mounts but the cage held up over enginering ftw :)

[bullfrog]

I think it may have been tomcat or similar(dont quote me) who used to make theirs out of scaff tube. I have an old 4x4 book somewhere and they speak highly of it. Most of the problems seem to come from poorly fabricated cages not the materials.
I am no expert but I am a fabricator .
Banger boys still use it and I have seen many a barrel rol and the cage held up fine ?
There seem to be different spec scaff tubes as well which dosent help !

[Eeyore]

I think it may have been tomcat or similar(dont quote me) who used to make theirs out of scaff tube.

Thats the key phrase - 'used to'. If it's being sold to the public, it has to made to standards, and the standards call for specific tube types which scoffold pole doesn't reach.

Having raced bangers a couple of times (d'oh!), I have to say the safety mandate for that sport is abysmal. Heck, we even had a'cage' built from alloy scaffold, which really was a dumb idea (dude, what we're we thinking!). But as was said, no one gets hurt. A banger weighs nowt. Take a 1 ton car and strip it of everything and it weighs even less - it applies very little force to the cage when it goes over. Take 1.8 t 4x4, fill it with fuel, gear and body armour, place it on a steep slope and a lot of force can be applied to cage if it all goes the way of the pear.

As Wolfie says, I know what I'd rather have over my head.  

Most of the problems seem to come from poorly fabricated cages not the materials.

Interstingly, when a cage fails, it will usually do so at the weld (same as bike frames). Does this mean the weld is bad? Possibley, possibley not. The welds on tubular structures are always sited at the points of maximum mechanical stress (i.e. the node twixt two or more tubes). So we put a weld there just to add the stress from that too. Welds fail prematurely for a number of reasons too - bad welds and bad parent material. Bad parent material increases your chances of a bad weld by about a factor of oodles.

And lets not even get started on T45!........

cheers
 8)
Eeyore

[bullfrog]

I agree other than I dont know many jags that weigh a ton ! :lol:

[Eeyore]

I agree other than I dont know many jags that weigh a ton ! :lol:

We were cheap and used a Maxi!  :lol:

We were poor, it was my only excuse!!  :lol:

cheers
  8)
Eeyore

[woody]

I agree other than I dont know many jags that weigh a ton ! :lol:

We were cheap and used a Maxi!  :lol:

We were poor, it was my only excuse!!  :lol:

cheers
  8)
Eeyore

i used an escort then a maxi great fun at the time and my roll cage was the best quality scafold tube that i could find lying around the yard :oops: