Link lengths,is this long enough?

[RAY185]

sweet ive already got some 32nb here so i can start making them

What wall thickness?

[georgey]

i think its 3.2mm

[80lsy gq]

i think its 3.2mm

that wont be strong enough for links..

you need to get some 40/25 Hollow Bar..either that or sleeve the 32nb with 25nb and then put 40nb on the outside of it all..

i know which is easier

also run some 25x12 flat on its side on top of the links if you want more strength..this is for lowers..for uppers i use a 4-5mm wall tube

dave

[WRXZook]

Is this the right bar... carbon steel hollow bar?

http://www.edconsteel.com.au/pdfs/products/750HB.pdf" onclick="window.open(this.href);return false;

[georgey]

Is this the right bar... carbon steel hollow bar?

http://www.edconsteel.com.au/pdfs/products/750HB.pdf" onclick="window.open(this.href);return false;

yeah mate.The 40 means 40 O.D and the 25 means 25 I.D so essentially it has a 7.5mm Wall Thickness.

Could even go 40/20 if you wanted more strength.

While im over ordering the hollow bar tomorrow ill order some 40NB,this is the main roll cage material used in TT correct?
And ill get some 32NB for a few smaller sections i have in mind.

cheers

Justin

[uninformed]

is it true that hollow bar is also a better grade than normal black pipe "NB"

[lukethedork]

is it true that hollow bar is also a better grade than normal black pipe "NB"

Not sure what you Aussies call it. But ask for some Seamless or Mandrel drawn tubing (not real seamless). The Americans mostly use DOM (mandrel drawn).
In England they knew what I meant when I asked for Mandrel drawn.

Luke.

[rockcrawler31]

While im over ordering the hollow bar tomorrow ill order some 40NB,this is the main roll cage material used in TT correct?
And ill get some 32NB for a few smaller sections i have in mind.

cheers

Justin

Please don't make your cage material out of NB pipe. It's not seamless and it's NOT what you're supposed to use for a cage. Use the proper DOM or seamless tube in 1 3/4", call Andy Hall at performance metals and get the correct pipe. You might get away with it once it's built and not be able to tell the difference from a visual inspection but a shoddy cage is as usefull as a wet noodle in a heavy rollover. I'm guessing this thing's not going to be road legal right?

For reference i have a troopy chassis which is slightly longer again than the ute, using 80 series housings. As 80's delerious mentioned the standard lowers are 880 long and mine are about 1180 long. Even with that length of lowers i still get retarded amounts of rear steer when flexing (although it flexes like a mofo and the shocks are the only thing stopping the travel) so it's probably important that you get a grip on the calculator as well as a decent understanding of suspension dynamics and geometry theory before you go and cut a single bit of tube.

is it true that hollow bar is also a better grade than normal black pipe "NB"

NB means nominal bore IIRC, not "normal black". Whether it's better depends on dimensions and wall thickness, whether it's seamless or DOM, and the actual grade of steel.

[brooksy]

NB or nominal bore pipe is not as strong as it is normally around 250mPa while seamless HREW & DOM is 350+mPA.



brooksy

[rockcrawler31]

NB or nominal bore pipe is not as strong as it is normally around 250mPa while seamless HREW & DOM is 350+mPA.



brooksy

There you go. I defer to the dude with the worlds most goofiest lookin' dog.

[georgey]

NB or nominal bore pipe is not as strong as it is normally around 250mPa while seamless HREW & DOM is 350+mPA.



brooksy

Ive seen plenty of cages made from NB tube that have held up to rollovers.
Im not looking at doing 80km an hour and flipping it
it should be ok for slow stuff as long as theres alot of bracing and triangulation correct?

[rockcrawler31]

NB or nominal bore pipe is not as strong as it is normally around 250mPa while seamless HREW & DOM is 350+mPA.



brooksy

Ive seen plenty of cages made from NB tube that have held up to rollovers.
Im not looking at doing 80km an hour and flipping it
it should be ok for slow stuff as long as theres alot of bracing and triangulation correct?

I guess i see where you're coming from, particularly given the price difference between the two types of steel stock. BUT, you only have to be a quadriplegic, brain damaged vegetable once to see why it's worth the coin. (Just ask DRS )

There's two reasons why i'd disagree with your arguement.

Firstly is that you don't need to be doing 80km to need a strong cage. You only need to balls up once on a decently high hill to roll end for end 14 times. Just ask the guy in the white cut down 80 series who rolled off a hill in Victoria a little while ago why you can have potentially lifethreatening consequences at 3km/hour

Secondly is that you never know the end use of a cage. Yes you're only planning on doing TT with it now where you might fall off a single boulder at almost a standstill, but you just don't know if you're going to adapt the car to faster stuff later on. This is the reason why when i'm building stuff like this for anyone i INSIST on using DOM tube since i never know what the car COULD get used for.

[ISUZUROVER]

This may help with terminology (taken from a US forum):

DOM is a process drawing over a mandrel and through a die. It can be with a ERW electric resistance welded hollow or a seamless hollow, your seamless hollow desctiption is correct. CREW stands for Colled Rolled Electric Weld and can be drawn but does not mean it is drawn. The cold rolled portion is defining what condition strip is used to make the tube ERW is available Cold Rolled Hot Rolled and Hot Rolled Pickled and Oiled it is usually driven by thickness of the strip.

You can purchase ERW tube that is stronger than DOM it is all Chemistry / Grade dependent.

If you want to use Pipe Size ERW tube at least find out what grade it is, it could have been produced to the A513 standard or the A500 standards which would would be higher strenght. If it is A 500 Grade b it would be in the C1020 range. Hell they make A500 Grade C ROPS Roll over Protection Structure ERW that is in the C1050 range.

We started out talking about links, not cages.

However I recall the haultech guys saying their buggys were made from ERW. They have collectively suffered lots of hard flops and rolls with no failures I am aware of.

[v840]

Wendle's buggies have all been made from NB, have been through many rollovers and generally get driven harder than most would push their rigs.

Not advocating using it but cage strength is more dependant on design than material IMO.

[ISUZUROVER]

Not advocating using it but cage strength is more dependant on design than material IMO.

Or rather it is a function of design and material strength. You can make a cage just as strong using 250MPa tube as 350MPa tube if you take the material strength into account in your design.

Btw - I have seen places selling 320 and 350 MPa NB pipe.

[georgey]

I think ill stick with the NB tube.
Have made sliders,front and rears bars out of it and had no worries.

Just realised i cant use 40/20 or 40/25 hollow bar because i need an ID of 1.5'' to fit my heim joints in :(
Luckily they couldnt get me a price and i didnt order it today.

On another note,the price of tube has gone up a hell of a lot.
3 months ago when i got a price for 40NB it was just above $50 per length now its around $70,and thats cost price apparently.

[Micka]

This may help with terminology (taken from a US forum):

DOM is a process drawing over a mandrel and through a die. It can be with a ERW electric resistance welded hollow or a seamless hollow, your seamless hollow desctiption is correct. CREW stands for Colled Rolled Electric Weld and can be drawn but does not mean it is drawn. The cold rolled portion is defining what condition strip is used to make the tube ERW is available Cold Rolled Hot Rolled and Hot Rolled Pickled and Oiled it is usually driven by thickness of the strip.

You can purchase ERW tube that is stronger than DOM it is all Chemistry / Grade dependent.

If you want to use Pipe Size ERW tube at least find out what grade it is, it could have been produced to the A513 standard or the A500 standards which would would be higher strenght. If it is A 500 Grade b it would be in the C1020 range. Hell they make A500 Grade C ROPS Roll over Protection Structure ERW that is in the C1050 range.

We started out talking about links, not cages.

However I recall the haultech guys saying their buggys were made from ERW. They have collectively suffered lots of hard flops and rolls with no failures I am aware of.

The moon buggy built at haultech that I bought was built from ERW and had some very heavy rolls (including one that cracked a Mickey Thompson alloy rim clean in half). It survives even now, almost 7 years later with the same frame - though with a few slight alterations and replacement parts sleeved into it. There is no doubt that seamless DOM is the better product to use, but the ERW will also work. Just put more bracing into the areas surrounding you and ensure that the welded seam is not on the outside face of your bends - I have seen them peel open with impacts when the welded seam was on the outside of the bend.

Just be very aware that the product you are choosing to use is not the best one for the job.

Micka

[5inchgq]

Just realised i cant use 40/20 or 40/25 hollow bar because i need an ID of 1.5'' to fit my heim joints in :(
Luckily they couldnt get me a price and i didnt order it today.

Why can't you use 40/25 or 40/20 because your heim joints are 1.5" ?? Am I missing something ??
Surely you could have an appropriate size thread cut into them ???

[georgey]

Cheers Micka,i will be making sure where possibly to keep the seem on the inside of the bend


The weld in threaded bung for the heims are 1.5'' od and will fit snuggly inside a 1.5'' ID pipe
hence why i cant use anything smaller than a 1.5'' ID pipe unless i go a smaller heim which im not prepared to do.

[5inchgq]

Cheers Micka,i will be making sure where possibly to keep the seem on the inside of the bend


The weld in threaded bung for the heims are 1.5'' od and will fit snuggly inside a 1.5'' ID pipe
hence why i cant use anything smaller than a 1.5'' ID pipe unless i go a smaller heim which im not prepared to do.

Can you get the ends of the tube machined out to suit ???
Then drill the tube for some plug welds into the threaded section for strength ??

[georgey]

Hmm you could be onto something,although the weld in bungs are 50mm long so id need to find a pretty long boring bar.
thanks dude

[uninformed]

is it true that hollow bar is also a better grade than normal black pipe "NB"

NB means nominal bore IIRC, not "normal black". Whether it's better depends on dimensions and wall thickness, whether it's seamless or DOM, and the actual grade of steel.

yeah, NB is nominal bore, but 99% here buy it as black pipe, I was just referring to whats 'normal' from local steely suppliers........its also listed as CHS or circular hollow section.......even though its called nominal BORE its bore does change NOT the OD for its different wall thickness...ie, 32 nb can be had in light, med, heavy and extra heavy....all with the same OD, just the wall thickness and ID that changes....

Hollow Bar, I was under the impression was a better grade of material....Ive looked at the Euro Norm range from Bollar..... As I understand it the size 40/20 while being the OD and ID is actually the clean up size...thats to say, if you put it in a lathe and clean it up to round it will have these sizes...so expect a little bigger OD and slightly smaller ID off the shelf....

[Z()LTAN]

All the NB i have used is seamless

[rockcrawler31]

Well i'm happy to stand corrected as the NB stuff is craploads cheaper.

Just make sure you put up lots of pics georgey

[lukethedork]

All the NB i have used is seamless

Really? Do you have pictures or a MDS of the seamless NB you have used?
What sort of price did you pay then?

Luke.

[nastytroll]

NB is just short for nominal bore. Anything can be termed NB, even drawing sizes.

Just for referance. A Black pipe (as called NB above) cage will let you run down to a 10 sec 1/4 mile at something like 120+ mile per hour under ANDRA. If you want specs look up ANDRA cage specs. That was a 4 point with side intrusion and taxi bar, no crucifix needed.

[Z()LTAN]

There is seamed and seamless NB pipe. The stuff we use for hand rails and guards is seamed.

I got some NB32 shedule 40, NB40 shedule 40 & 80. This NB pipe is of a different grade to the seamed, welds better and has a laqured coating.

$90 for a 6m length for the 32 and $100 for the 40

Its good to work with but has a fair bit of springback on a bow and arrow bender.

[georgey]

For seam 32nb im paying $54for 6.5M length i think,may be 6M though im not 100%
For seamless 40NB its $70 for 6M length

Unsure of seamless prices as i didnt get a quote.

If the 40/20 is machined to suit the weld in bungs which are 1.5'' which is like 37mm id would end up havin a 3mm wall and it would be easier to just use 1.5'' ID pipe to save the machining.
You should be ablt to get 2'' OD with a 1.5'' ID,anyone confirm this?

[Z()LTAN]

NB40 schedule 80 would b close

[Surfection]

I'm not going to say that in most cases for most people Black Pipe won't do the job. However in my experience the strength difference between this and CDS or CDW tube is massive. Using a Protools or JD bender pictured below you could really tell the difference between bending the 2 different types of material in the same (3.2mm) wall thickness. I had a 1.5 mtr handle on my bender and could bend Black Pipe one handed with no real thought to where my hand was on the handle, by simple walking back with my body weight on the handle. With CDW or CDS it took both hands right at the end of the handle and most of the strength that my massive 68kg body weight could use to pull with. You also got less spring back with the tube than you did with the pipe, and the tube being better quality material was far kinder to the dies.

I would highly reccomend spending the extra $$$ and contacting Performance Metals or another specialist steel supplier to use quality tube, not pipe. It will pay for itself in the long run if you plan on keeping the car and driving it hard, it may also save your life.