Dry Lakes Racers Australia

The rule book says ' Low carbon (mild) steel tubing is recommended for the construction of all types of roll bars and cage type structures.' It then goes on to address mounting and installation, dimensions, gusset and welding requirements and makes mention of chrome moly etc but does not, that I can see, specify any specific tubing grade. I'm working on the theory that, in the event of a bad crash, I would prefer the cage assembly to distort and absorb energy rather than transfer all of the shock loading to my body. This issue has been addressed many times both on this and on the Landracing forums and I guess many people have many different views and given that the rule here is not all that specific and given that there is not really anything hard to run into on the salt, except if you get airborne, it is hard to find a specific answer. After all ours is not like speedway or circuit racing or even drag racing where contact sometimes occurs. Those guys have had lots of opportunities to develop and forumlate roll bar and cage specs - our people have not had so much opportunity and the best material to use and the best way to construct seem to be left for individual ideas and engineering. In these other forms of motorsports you are not given any leeway. To many thats the attraction of salt lake racing - not govered to the nth degree.
Maybe I should not have asked the question again at all and I'm sorry if I should not have and it stirs a hornets nest. Maybe I asked the question already knowing the answer that I wanted to hear but asked it for comfort or something and maybe I should have asked the chief scrutineer directly because at the end of the day he will be the one to give anything I present the yay or nay.

Teamleader
All l see here is healthy debate and a variety of comment. This forum is the right place for that and having it out in the open all of us building cars may benefit.
My 2 bob is mild steel everytime. Good design and weld quality are as important or more important.

Chris

C Hanlon wrote:Teamleader
All l see here is healthy debate and a variety of comment. This forum is the right place for that and having it out in the open all of us building cars may benefit.
My 2 bob is mild steel everytime. Good design and weld quality are as important or more important.

Chris

Seamless or welded tube Chris? Always helpful to get the advice of someone who's got the experience to back up their opinions.

There's talk of us going to the SCTA rule book?
Whats their ruling on roll cage construction?
Would be a shame to build one and have to rebuild it in the near future.

Thanx
Dave

teamleader wrote: Maybe I should not have asked the question again at all and I'm sorry if I should not have and it stirs a hornets nest.

TL,

There's no such thing as a stupid question (only stupid answers), in fact if there's any doubt, particularly for a safety related item, it'd be foolish NOT to ask.

I got two more leads this evening for CDS, Monday will be a telephone day for me.

Cheers,
Rob

Yes - I see that Ross Brown has done his entire build in stainless tubing. I would like to see a comment or two from him on that.

teamleader wrote:Yes - I see that Ross Brown has done his entire build in stainless tubing. I would like to see a comment or two from him on that.

Yeah, I thought stainless was an odd choice. I'm guessing (hoping?) he's contacted one of the DLRA tech guys before going that way.

Maybe a well engineered and fabricated vehicle made with inferior materials is going to be more surviable in a bad bingle than a badly engineered piece made from the worlds most exotic materials. Unless you have the resources to destruction test as per F1 will any of us ever really know? I hope we don't have to find out but no matter, we must all still strive for the safest and most surviveable end product that we are capable of coming up with.

Progress report:

Van Leewen has seamless hydraulic tube at 44.5mm and 3.25mm wall but cannot tell me the steel properties without going and testing a sample.

The Steel Store doesn't do seamless.

Bohler-Uddholm don't do 1 3/4" OD seamless.

STAINLESS STEEL
why ?
Salt infected conditions.
why not ? apparrently work hardens! all metals, bar GOLD work harden. this usually happens in the build process if built incorrectly drilling the material at the correct speed is important .100 to 200 rpm
not usuing a filling rod while welding will burn out the nickle ,thus creating a floor in the project. bad design as team leader wrote will also floor a project .
I DO NOT RECOMEND A FIRST TIME BUILDER TO USE STAINLESS.
as unless u have full workshop facillities with jiging equipment & knowlodge of when & when not to weld you will never hold it straight.
HAVE been using stainless in racing aplications for 15 years & am yet to have a failure . the out fit pictured is one of 4 completley built from stainless It has done 5 seasons work (over 300 races) . the CHASSIS IS THE FUEL TANK. It has been cartwheeled down the main straight at full throttle & has generally been beaten up & has still not leaked a drop of FUEL.


IN 1962 The Eglish built an aircraft THE BRISTOL 188 nicknamed THE FLAMING PENCIL it was built to soak Mach 2.6 to achieve the required strength the structure was largley stainless steel . it achieved Mach 1.88 (structure was good ,engines not powerfull enough ) soon after the SR71A predesser to the BLACKBIRD ruled the skies ,
A TESTAMENT TO STAINLESS STEEL !

THE RULE BOOK!
Is given to us as a MINUMIN guide as BOB ELLIS has pointed out to me
their is no penalty to build above that .
LOW CARBON SEAMLEES STEEL is the recomended product to use .as it is forgiving in areas of production were the more exotic materials are not.
If wanting to use CHROME MOLLY buy it in 4130 COND N build your your chassis or cage . then send it out to be heat treated & stress relieved. THAT IS THE CORRECT PROCEEDURE !

Meanwhile, per the thread topic, I'm still looking for seamless tube.

Maybe we can get the stainless discussion moved to Ross's build diary?

As a general observation and personal opinion, we should be building to the rulebook not trying to flex the rules to suit our builds.

Cheers,
Rob

G'day Ross,

I don't want to perpetuate the discussion here but the correctly quoted rule (Rule 4.2 paragraph 2) states:

"Low carbon (mild) steel tubing is recommended......"

EDIT: Sorry, I was reading the auto section not bikes. Streamlined bike rule 7.H.4 says "mechanical steel tubing. No gal pipe, no black water pipe and no screwed fittings" so it appears anything goes for streamlined bikes providing the scrutineers are happy.

Cheers,
Rob

Hearing Ross's opinions is good, don't go moving stuff around. It's a good topic the way it is.

Ross knows his stuff obviously.

Me, I'll be using mild steel because I'm a hack.

G'day blownvn,

I'm not discounting anyone's opinions but am still trying to find cold drawn (mild steel) seamless tube which was the reason I started the thread.

It's a good discussion but should be in it's own thread or Ross's build where it's more relevant.

Cheers,
Rob