Welding Required

[Tatey]

What are the thicknesses of the steel required to be welded (im still waiting for WH Smith to deliver my build book)?

I know the chassis tubes are 1.6mm, can this thickness be changed? I know it will increase the weight and cost slightly, but im sure it would be cheaper than spending £200+ on a mig welder, would there be anything wrong with using 2.5mm box?

[Bonzo]

I would not even think of using 25X25 RHS box section to build a spaceframe chassis.

The weight gain would be unaceptable :eek:

Although I am not a race engineer, I can also forsee structural reasons as to why this material is not suitable.

If you really do not want to buy a MIG welder, why not tack your chassis with the stick welder, then hire or try and borrow a MIG to fully weld the chassis.
This will probably work out cheaper than the extra cost of RHS box. ;)

[Tatey]

I've done a few calculations based on using 1.6mm thick box and 2.5mm box. Based on using 36m of box and 1.6mm thick it comes to 42.4kg and using 2.5mm box it comes to 63.67. This is quite a large % increase in mass but in the grand scheme of things it isnt much since someone of the larger build than me could easily add double that mass.

There isnt that much of a price change. 1.6mm box is £14 per 6 m, i havent got a price for 2.5mm 25x25 but 3mm 30x30 is £20 for 6m so im guessing 2.5 25x25 would be about £17-£18 so thats £24 more maximum for the steel used.

[HandyAndy]

i understand in a way what you are saying but have to ask WHY? the design of the chassis has had structural tests etc & has no need for the extra thickness steel that you suggest :confused:
i,m not knocking your thoughts just not sure why change a working formula.

as for the welding required... the way i see it its part of the ethos of the concept "build your own sports car".

i couldn,t weld until i started a course at local technical college in january this year, my welding might not ( i know its not ) be to qualified cert standard but feel confident enough to build my chassis & drive it once completed, & if you build your own chassis you will "know every inch " of it which when its on the road is something to be very proud of.
each & everyone that is building a Roadster has put there own little "touches" into it whether to everyones liking or not, its your car that you built.:cool:

cheers
andy

[Tatey]

Hi Andy,

The reason i ask is because i already own an arc welder and loads of 2.5mm rods and im reasonable at welding with them, but its difficult to weld less than 2mm thick, which im guessing is why everyone recommends buying a mig welder. Im trying to cut down costs and 1 of the major expeditures was on a mig welder, which would be £200+, i've tried to find a cheap one but to no avail.

So i thought why not get rid of it and just increase the thickness of the steel box meaning i can just weld it with my trusty arc welder since there dont seem to be too many downsides that i can see, 1 being it adds an extra 20kg to the chassis and the other being it will cost another £30 for the steel.

Im just wondering if there are actually any major reasons im missing as to why 1.6mm thick tube was chosen, which would mean that 2.5mm thick tube would not be appropriate.

[Bonzo]

ERW square tube, 1.6mm wall thickness, is the material required for the chassis.

By all means use RHS box to build you chassis. :rolleyes:

Sorry to put it bluntly but if you are willing to make bad choices in the name of cost at this early & critical stage, where will it end up :eek:

[Tatey]

Ohh sorry i didnt realise it used ERW square tube, i've just been going on things i've read on the forum as i havent got my build manual yet. I'll give my local steel merchant a ring tomorrow and see what prices are like.

I have to say im not too much in the know about different kinds of mild steels, whats the difference between ERW and RHS?

[HandyAndy]

my apologies i may have misunderstood your thoughts/questions.
i,m not the person to answer why 1.6 steel was chosen for the design ( maybe Chris will confirm the reason ).
i,ll be totally honest & say i had the same thoughts as you whereas i had the offer of free use of an arc welder ( my brothers ) before i started my build & asked the very same question... can i use an arc instead of a mig, i decided once i,d done more research into the building of the chassis that mig was the way to go,
i bought my mig off the "mig welding forum" second hand for £50, its a 150amp & came with 2 large pub style gas bottles so the bargains do come up now & again, guess i was lucky as it works perfectly.
i,m trying to build to a strict budget, ask Ash G :D ;) & as close to the book instructions that my ability will allow.
i think if you used the heavier gauge steel it may cause more probs than it alleviates at first.
best wishes for your build by the way.:)
cheers
andy

[fabbyglass]

Don't use 2.5mm wall, not sure you can get the precision tube in that guage anyway. If not then it will be that black rubbish with only one square edge if you are lucky.
Why nost ask a forum member to make you one

[Land Locked]

I have to say im not too much in the know about different kinds of mild steels, whats the difference between ERW and RHS?

I second this question, I am now concerned about using the wrong material.:( :confused:

I hate TLA's(Three Letter Acronym's)!:mad:

[fabbyglass]

1.6mm can be stick welded if you are careful

[fabbyglass]

ERW is the stuff to use rhs will usually be the black stuff and no good for a chassis as it isn't very square...

[Bonzo]

I have to say im not too much in the know about different kinds of mild steels, whats the difference between ERW and RHS?

One major difference between RHS & ERW are the edge profiles.

RHS has a very pronounced rounded profile edge. Using this material will lead to a greater risk of welding distortion.

ERW is a precision electro welded sqare tube & has a very fine corner profile ;)

[Tatey]

Yeah i've researching into welding 1.6mm, it would require buying some more rods and require a lot of practise as i dont want to end up blowing holes.

So does anyone know why ERW tube is used for chassis and the like? Whats so special about it? Does it add extra strength?

I have learned that ERW tube is made by taking a strip of metal and then folding or rolling it to the shape desired and then welding down the seam and cleaning off the outside weld.

[flyerncle]

ERW electric resistance welded, RHS really horrible stuff.:rolleyes:

[Land Locked]

With a bit of practice it's a breeze to stick weld 1.6mm.

[fabbyglass]

ERW is electro resistant welded tube RHS is rolled hollow section....ERW is better quality where RHS is not so clever especially for a chassis.

[Tatey]

Right looks like i might go down to my steel stockist and get some 1.6mm steel bar and have a practise. Someone on the mig welding forum has shown me a pic of where he's welded 1.6mm tube together using the 2.5mm rods im using so looks like i might just go down that route.

Im still curious as to why ERW is better though, what is it other than the corner profiles that makes it so much better.

[fabbyglass]

RHS is black and full of crap where ERW bright and a better quality tube, there is a lot of iffy rhs out there and doesn't weld very well..

[Bonzo]

I second this question, I am now concerned about using the wrong material.:( :confused:

I hate TLA's(Three Letter Acronym's)!:mad:

If your square tube is 1.6mm wall thickness it is almost certainly ERW ;)

[fabbyglass]

RHS is not what you would call square and usually twisted where the ERW is precision tube.

[Chris Gibbs]

The 1.6mm ERW was chosen because it's strong enough to do the job and it's light. Using RHS would make a strong and heavy chassis but it doesn't deform in the same way as ERW in an accident, the progressive collapse by buckling is preferable to joints breaking and possibly pushing tubes into the passenger compartment.

Cheers

Chris :)

[Tatey]

Thanks for clearing that up Chris. Whats the cost difference between ERW and RHS?

[HandyAndy]

Thanks for clearing that up Chris. Whats the cost difference between ERW and RHS?
i paid £9.70 per 6mtr for 25x25 1.6 and
£7.40 per 6 mtr 19x19 1.6
plus £15 delivery , i think total was £115ish
this was ERW

andy

[Tatey]

Talk about bargain prices. May i ask who your steel supplier is and how far a field will they deliver to?

[HandyAndy]

Talk about bargain prices. May i ask who your steel supplier is and how far a field will they deliver to?
i haven,t got the receipt with me at mo ( its with my chassis, being built at mothers place), i,ll get you the details tomorrow & post it on here, not sure how far they deliver but imagine they would to your area,
they don,t hold the steel in stock, they are like a stockbroker, you place the order & they get the best deal for you.
the above prices included VAT too, as i said i,m building to strict budget :D ;)

andy

[AshG]

ok guys im gonna throw a big spanner in the works. the book states 16gauge box section. 16gauge is 0.0598inch thick so actually its 1.51mm.

sorry just being silly tonight

i dont know what your faffing about my arc welder will weld up 16gauge no problem. the trick is to strike the arc on the corner as its the most heat resistant bit.

[fabbyglass]

The more you buy the cheaper it will be so why not get a few of you and do a "group buy" on the tube?....:D

[Bonzo]

ok guys im gonna throw a big spanner in the works. the book states 16gauge box section. 16gauge is 0.0598inch thick so actually its 1.51m

Ahhhhh..... That will be the nominal thickness :D :D :D :o

[Tatey]

So just to make sure, it will be 1.6mm, not 1.5?

[HandyAndy]

The more you buy the cheaper it will be so why not get a few of you and do a "group buy" on the tube?....:D
i,m happy to ask my supplier for a good group deal & see if they,ll do multiple deliveries, or if you are local to me have it delivered to me & you collect = 1 delivery charge of £15. also they will cut it into 3mtr lengths if you wish.

andy

[HandyAndy]

So just to make sure, it will be 1.6mm, not 1.5?
its known as 16gauge when i queried the dimensions with my supplier, its fine.
andy

[Tatey]

Im up for a group buy if it would be feasible as i wont have the money for a few months so we could hopefully get a few people interested.

[AshG]

just to clear this up RHS = Rectangular Hollow Section. you need square box section also called SHS = Square Hollow Section.

ERW = Electronically Resistance Welded. this is one of the ways RHS and SHS are made.


What you want to order is SHS ERW bright mild steel 16gauge 25x25mm. which in simple terms is a shiney square metal tube with a weld all the way down one side of it.

Simples :D

[Bonzo]

So just to make sure, it will be 1.6mm, not 1.5?

Yes 1.6 ERW square tube is the material to ask your stockist for ;)

I believe that this tube has been made in both metric & imperial sizes, hence the 16 gauge 1" X 1" & 3/4" X 3/4"

My steel buyers guide lists only metric sizes for ERW. :)

[AshG]

Handy little snippet if you fancy a read.



Cold formed, electric resistance welded tubing can be produced in round, square or rectangle shapes. ERW tube is produced by processing a flat rolled steel into strips which are cold-formed, welded and seam annealed or normalized (depending on the manufacturer). You can usually identify ERW tube by the blue strip down one side of the tube (which is the welded area). The ERW process can guarantee the weld to be as strong or stronger than the rest of the tube body. The origin from a flat strip results in a more concentric product than Cold Drawn Seamless (CDS). ERW can also be known as CREW (Cold Rolled Electric Welded).
Typical Applications:
Structural columns, beams, supports, heavy equipment frames with 58,000 PSI tensile.

Cold Drawn Welded (CDW)
Produced from a steel strip by cold forming, electric resistance welding (ERW) and cold drawing to finished dimensions, CDW is the most versatile and widely sold mechanical tubing grade. A variety of thermal treatments can be applied to alter the mechanical properties and machinability. CDW is used for a tremendous variety of machine parts where close tolerances and higher mechanical properties are needed.
Typical Applications:
Automotive components, shock absorbers, hydraulic cylinders, sleeves, bushings, axles and shafting.

Drawn Over Mandrel (DOM)
DOM is formed from strip and Electric Resistance Welded (ERW) then cold drawn through a die and over a mandrel resulting in improved inner surfaces and dimensional quality. This process, called cold drawing, may be repeated more than once to reach the planned OD, ID, or wall dimension. Multiple draws can also be used to increase the strength or improve the surface finish of the tubes. During the drawing operation, the tubes may be process annealed to increase the ductility of the material. Lower cost alternative to CDS with equal or superior physical properties.
Typical Applications:
Machined parts, rollers, shafts, sleeves, steering columns, axle tubes, drive shafts, bushings and is most readily adaptable in cylinder applications with a 80,000 PSI tensile.

Cold Drawn Seamless (CDS)
General purpose seamless tubing, which is a solid bar of carbon steel drawn over a mandrel to form the tube section. CDS allows selection of chemistry and rough tube size. Cold drawing produces higher physical properties without heat treating. Offers widest range of sizes and chemistries in mechanical tubing. Better tolerances and reduced machining allowances over Hot Finished Seamless (HFS).
Typical Applications:
Machined parts, bushings, spacers, bearings, rollers, shafts, sleeves and cylinders with a 75,000 PSI tensile.

Cold Rolled Electric Welded (CREW)
Cold rolled steels are steels that are shaped by high pressure rollers at normal temperature in the steel mill. Cold rolling work hardens the material substantially. The steel is then welded by the electric weld process. A cold rolled steel can be either a mild steel or a high carbon steel. Can also be termed as ERW (Electric Resistance Welded). See » ERW

Hot Rolled Electric Welded (HREW)
Hot rolled steel is steel that is rolled to size in the mill while red hot. Hot rolling steel does not work harden it as much as cold rolling. For this reason, hot rolled steel is more easily machined than cold rolled.

What's the difference between Tube and Pipe?
The general term for pipe was that it was primarily used for carrying gas or liquid. It was not intended for structural use because the dimensions used in describing pipe was not dimensionally accurate. Measurement was referred to its inside diameter and wall thickness. The inside diameter was a true dimension, but over the years had become "nominal" (in name only) so that when pipe size was referred to, it was an approximate inside diameter measurement with the thickness described by the term "schedule".

[fabbyglass]

shaved chicken legs and hairy mole ears

[AshG]

shaved chicken legs and hairy mole ears


and breathe :D

[fabbyglass]

Cats ears make nice comfy pads where bits on the chassis might rub you..:confused:

[HandyAndy]

and breathe :D
Ash, did you type that long thread or pasted it????:eek:
how,s the build?
andy

[AshG]

Ash, did you type that long thread or pasted it????:eek:
how,s the build?
andy


i typed it out for another forum ages ago but saved it in notepad as i knew it would be usefull one day.

cracking on got the rad today so that will be going on this weekend. i have got about 10 jobs left on the list to do before i can sand blast and paint the chassis. then its on to floor and body pannels, pipes and wires, fuel tank, running gear, engine..............sod it i can't be bothered to type any more.

[davidimurray]

Generally - RHS (Rolled Hollow Section) is considered as a structural steel and as such will be less less strict tolerances then ERW (Electric Resistance Welded) or CDS (Cold Drawn Seamless). RHS will normally come in the 'black' form straight out of the mill whereas the others are likely to have been cold rolled and/or pickled to get rid of the scale. For our applications, the existance of the weld does not really make any difference. Typically ERW is so good nowadays that if you cut the tube and look at the weld under a microscope it is very difficult to distinguish the difference between the weld and the parent metal. Where you often will find differences will be when it comes to using these 'hollow' sections for pressurised pipework - as ERW ahs a lower 'joint' factor than CDS which reduces the overall pressure rating of the pipe - guess what I've been doing at work recently :p Interestingly, I did some work comparing the cost of ERW and CDS for a job at work and found there was no clear difference between the two, for some stuff one was cheaper than the other and for others the reverse applied. One other thing to bear in mind when ordering is that the tube is typically supplied in 'random' lengths - these are between 5.7m and 6.1m - it is easy to get caught out by this and assume they are 6m lenghts - been there done that :rolleyes:

Cheers

Dave

[davidimurray]

What's the difference between Tube and Pipe?
The general term for pipe was that it was primarily used for carrying gas or liquid. It was not intended for structural use because the dimensions used in describing pipe was not dimensionally accurate. Measurement was referred to its inside diameter and wall thickness. The inside diameter was a true dimension, but over the years had become "nominal" (in name only) so that when pipe size was referred to, it was an approximate inside diameter measurement with the thickness described by the term "schedule".


Interestingly, or maybe not, Our Euro/British standard friends seem to have now standardised on the term Tube for any fluid/gas conveyance tubing!

[Land Locked]

Handy little snippet if you fancy a read.



Cold formed....(Edited to save space)....measurement with the thickness described by the term "schedule".

Thanks for a very very useful post, now I know what I'm looking for.

[Land Locked]

The other welding question.

It would appear that the Sarf Efriken sevenesque people look with disdain on any form of welding except TIG. To them TIG is the the holy grail AND the only remotely acceptable way to weld a chassis. Yes TIG makes very pretty welds, but do we need to be that anally retentive?

[Tatey]

I dont think we do need to be that analy retentive. As if you're welding properly then the material should break before the weld does.

[AshG]

i started of with the mig on my chassis then wnet to tig then back to mig as the tig was to slow for someone impatient like me.

i only crack the tig out for little jobs like closing up the ends of the chsaais tubes these days. oh and it will come out again to do the ali fuel tank.

[RAYLEE29]

Hi, just a thought,
is it true that tig produces a more brittle weld than mig because of the intesity and concetration of tig welding?
I was told this by a fabricator years ago.
Ray:)

[fabbyglass]

Done properly it's better as you can control the heat you are putting in as well as the filler rod, where mig is more brutal but then hairy chickens legs against bald mole legs:confused:

[RAYLEE29]

I would have used my tig for some of it but couldnt justify the argon bottle hire price and i get my co2 for a £1 a kilo.:)

[Tatey]

Well i've just ordered 6m of 25x25 16 gauge square hollow section. It came to a grand total of £22 :eek: Im hoping that its going to be the ERW stuff so that i know that that what im welding is the same stuff that the chassis is made of, i think i'll have a practise with it first and then make myself a welding trolley for my arc welder, mask and rods.

WH Smith have finally posted my build guide and i should have it in the next few days.

[AshG]

at that price your better off buying the steel precut from armoto. p.s motor world sell the book for £15 rather than the rrp of £18

[Tatey]

Yeah im going to see if HandyAndy's supplier will deliver to me, if not i could get it delivered to him and drive down and collect it if he's alright with that.

I've had a go arc welding the tube, it doesnt seem too hard, with a bit of practice i recon i could have it cracked.

I managed to get the book for £11.51 from WH Smith, its also £12.50 on amazon with free delivery.

[fabbyglass]

If you are new to stick welding try and do as many welds on the flat rather than vertical as that's where it gets tricky

[Bonzo]

If you are new to stick welding try and do as many welds on the flat rather than vertical as that's where it gets tricky

A nice spell of overhead welding with the stick is great fun :eek: :D

That is why I sport a Friar Tuck hair cut :D :o

[fabbyglass]

Pipe welding on site where you can't turn the pipe or get at it very well oh and it's ideal if the fuel oil running thru it stays in it afterwards...blowing a gale and chucking it down with rain just to make it interesting:mad:

[Bonzo]

I once had to cut out the cargo pumping lines from a ship that was used to transport molasses. :rolleyes:

We used gas axes. Boy did those pipes spit & fart :eek:

I got my wormate a beauty.

He was bending over the cut end of a pipe, removing some brackets. When I cut through the pipeworwk further downline, the resulting flash got him right up the Jacksy :D :D

[Tatey]

I've done a little bit before using some 6mm flat bar which was easy peasy. I've just learned why you shouldnt weld near flamable object though, 1 ruined car sponge later lol.

Although i have another issue now. My dad says there wont be enough space to have both the car and the crap he's put in there as i just have a single garage. Would someone be able to give me the dimensions of the completed car so i can try and prove him wrong?

[HandyAndy]

Yeah im going to see if HandyAndy's supplier will deliver to me, if not i could get it delivered to him and drive down and collect it if he's alright with that.

I've had a go arc welding the tube, it doesnt seem too hard, with a bit of practice i recon i could have it cracked.

I managed to get the book for £11.51 from WH Smith, its also £12.50 on amazon with free delivery.
Hi, just spoke to my steel supplier who said he can,t deliver to your area but you would be welcome to send a courier firm to collect on your behalf, or have it delivered to me & you collect from my place. confirmed prices as of 2 minutes ago are
25mm x 25mm ERW 16gauge = £ 9.72 per 6mtrs
19mm x 19mm ERW 16gauge = £ 7.94 per 6mtrs
delivery charge to me = £ 17.25

all above prices include VAT.
they will cut it in half at no extra cost.

let me know if you want to order.
cheers
andy

[Tatey]

Cheers for that andy. I think i'll want to order in a few months once i've got everything planned and some money together.

Does anyone know where i can get a cheap 240-110V transformer, my chop has just arrived and im needing to sorce a transformer for it?

[Bonzo]

Hi, just spoke to my steel supplier who said he can,t deliver to your area but you would be welcome to send a courier firm to collect on your behalf, or have it delivered to me & you collect from my place. confirmed prices as of 2 minutes ago are
25mm x 25mm ERW 16gauge = £ 9.72 per 6mtrs
19mm x 19mm ERW 16gauge = £ 7.94 per 6mtrs
delivery charge to me = £ 17.25

all above prices include VAT.
they will cut it in half at no extra cost.

let me know if you want to order.
cheers
andy

That is a very good price for the steel Andy :cool: Well cheaper than my local stockist.


Tatey

110V Transformers are often to be had cheaply on ebay. ;)

If you want to buy a new one have a look at Machine Mart the prices are not too bad :)

Linky (http://www.machinemart.co.uk/shop/range/details/portable-power-tool-site-transformers/path/transformers-inverters-phase-converters-sol)

[flyerncle]

Tatey,if you are in Newcastle upon Tyne, pm and I will give you a good supplier and they deliver.

[Tatey]

Im 15 miles outside of newcastle towards hexham. How cheap are they? Are you currently building a roadster?

[flyerncle]

Yes to Roadster and I think less than quoted on here previously.Can find out if you need.Near Blaydon in Gateshead.

PM'd you

[Tatey]

Did you say you're in Blaydon or the firm is in Blaydon? As i picked the 6m of steel up from Franklin Steel in Blaydon earlier on.

[flyerncle]

I am near Blaydon,Franklin were too expensive.

[Tatey]

Ah ok. Which firm was it that you bought you're steel from? How far are you with your build?

[MightyMouth]

Can I suggest that if you dont think you will use the mig welder after you have finished the build that you can easily sell it for most of your money back.

[fabbyglass]

Shame I'm so far away as could offer a "hire me mig" service it's a single phase Cebora 186 stag and sits idle, in fact it hasn't even been connected back up since I moved workshops back in November 08...:o Not for sale though as had it 9 years and works spotty dog.

[Land Locked]

The 1.6mm ERW was chosen because it's strong enough to do the job and it's light. Using RHS would make a strong and heavy chassis but it doesn't deform in the same way as ERW in an accident, the progressive collapse by buckling is preferable to joints breaking and possibly pushing tubes into the passenger compartment.

Cheers

Chris :)

Of the many local steel suppliers I sent e-mails to, the only one who got back to me is the one who supplies to the folks who makes chassis locally. (If I'd known it was them I would have worded my mail very differently.) Anyways, they're saying I'm wasting money buying the ERW, He says that RHS in 1.6mm is quite acceptable.:confused:

That said, our RHS does seem to be very square and quite uniform in terms of thickness.

Maybe just a spot of clarification, as I understand RHS it is a hot rolled induction welded tube Whilst ERW is cold rolled. I am quite prepared to accept that I have it all wrong.:(

So right now I am as confused as can be, please help and use small simple words.;)

[Tatey]

Personally i would much prefer to trust Chris and the Haynes name and over prepair, compared to someone from a steel company.

Chris seems to have done a lot of work getting the car to where it is now.

And would you really want to risk buying inferior steel for a car that you and another people would be in?

Would you be able to live with yourself knowing that you might have injured/killed someone close to you because you wanted to save a few £'s?

[Land Locked]

Personally i would much prefer to trust Chris and the Haynes name and over prepair, compared to someone from a steel company.

Chris seems to have done a lot of work getting the car to where it is now.

And would you really want to risk buying inferior steel for a car that you and another people would be in?

Would you be able to live with yourself knowing that you might have injured/killed someone close to you because you wanted to save a few £'s?


No argument with any of these points, just having trouble sourcing the good stuff locally.

[Land Locked]

The reason i quoted Chris' post was cause he didn't specify the wall of the RHS that would make it heavier. As I understand RHS and ERW have the same density.

So the question I didn't ask (I plead lack of sleep), Is it the RHS thats heavier or more dense or is it because of the wall thickness that the RHS would be heavier and more likely to break than deform?

However at the end of the day the above is all academic as I am still hunting down a supplier for ERW, there has to be a couple of them here in SA.

Edit to add: Does this appear to be the right stuff? http://www.robor.co.za/cold_rolled_tube.htm

[ray3.2]

Robor looks as good a place as any to get your steel from. Check out the DIN specs and BS specs on google.

[Tatey]

Just rang up a local a local steel stockist recommended by flyerncle. Got quoted the following:

£10.85 per 6.1m - 25x25 16swg ERW
£6.45 per 6.1m - 19x19 16 swg ERW
£8.05 per 6.1m - 19mm diameter bar

So comes to a straight £100. Well pleased with that price.

[Bonzo]

A decent price is that ;)

That is more than £50 cheaper than the last quote I had from my local stockist. :eek: :confused:

Don't be stingy when buying the sqare tube

7 lengths of 25x25 & 3 lengths of 19x19 ought to be about right. The jigs use away to some of the 25x25 & you wouldn't be human if you did not have the odd cock up when cutting the steel.

Best pay for delivery once ;)

[flyerncle]

Would I lead you astray....?

[fluxcored]

The reason i quoted Chris' post was cause he didn't specify the wall of the RHS that would make it heavier. As I understand RHS and ERW have the same density.

So the question I didn't ask (I plead lack of sleep), Is it the RHS thats heavier or more dense or is it because of the wall thickness that the RHS would be heavier and more likely to break than deform?

However at the end of the day the above is all academic as I am still hunting down a supplier for ERW, there has to be a couple of them here in SA.

Edit to add: Does this appear to be the right stuff? http://www.robor.co.za/cold_rolled_tube.htm

Sorry to resurrect this thread - maybe I should have PM'ed Land Locked.

Land Locked .. did you manage to source some ERW. I had the same problem a few years back and just used RHS but Chris does present a powerful argument, I must say.

Cheers.

[Land Locked]

Flux, sadly not yet. Not a huge problem as I'm still trying to get the time to clear the workshop.(should have comfortable parking 4 three cars and all the benches, lucky to get one in at the moment):(

The local guys keep asking what it's for and then insist that the hot rolled is more than adequate.(buggers) I may well end up getting a chassis pack off e-bay.

[fluxcored]

I'll make a few enquiries and let you know what I dig up but I've got a sinking feeling I'll also be forced to get an Ebay chassis pack.

I hear you. I absolutely hate the so called engineering shops and steel suppliers down here. Either they have'nt got a clue to what I'm talking about or am totally disinterested in providing assistance. I always end up shipping stuff in from Port Elizabeth and/or Cape Town.

[fluxcored]

There's a guy in PE that's close to completing a mid enigined car and he's a member of the Locost forum. I think he's some kind of engineer that works for a firm that produce containers for overseas clients or something similar - he seems to be very knowledgeable and highly skilled and it shows in the build pics I have seen. I believe he's very highly regarded.

I'll try to establish contact with him on Locost.co.uk. Been a long time since I posted there.

Keep your fingers crossed!!!!!

[fluxcored]

Well... not very encouraging results thus far. Seems an Ebay chassis pack is the route to go!

[thwang]

should i start my chassis again i,ve used 25x25x2mm rhs the reason been it was very very cheap.
thwang

[fluxcored]

should i start my chassis again i,ve used 25x25x2mm rhs the reason been it was very very cheap.
thwang

I hate the idea of importing a chassis pack - it's like bringing coals to Newcastle. There's quite a few mills here in SA that seems to produce ERW but looks like the distributors do'nt want to sell it to small fry like us.

Most of the local guys, I have spoken to over the past few days have used rhs.

Which, I do'nt mind using. Problem is, I know that if I get this car built, my wife and son is prolly going to hog the car and I'll never forgive myself if something terrible happens to them due to to me not following specs.

Dunno know, maybe I'm worrying too much about nothing.:confused:

[Land Locked]

Just to throw the cat amongst the pigeons again, Ron Champion specified RHS for the original Locost.

[mr henderson]

It's my understanding that RHS means rectangular hollow section (just as CHS means circular hollow section)

Therefore ERW in square form is just a type of RHS. Maybe ERW is made in a way that isn't suitable for the thicker sections?

So, when I look in the tube details appendix in Chris's book and see that RHS is specified for all the square tubes, I assume that means ERW RHS because that is what is available in the 16 gauge that is appropriate for this type of chassis.

I am using ERW, BTW. If I lived somewhere where ERW in 16gauge was not available, then I would use whatever was available (as long as it wasn't outrageously heavy) and not worry about it.

[Land Locked]

It's my understanding that RHS means rectangular hollow section (just as CHS means circular hollow section)

Therefore ERW in square form is just a type of RHS. Maybe ERW is made in a way that isn't suitable for the thicker sections?

So, when I look in the tube details appendix in Chris's book and see that RHS is specified for all the square tubes, I assume that means ERW RHS because that is what is available in the 16 gauge that is appropriate for this type of chassis.

I am using ERW, BTW. If I lived somewhere where ERW in 16gauge was not available, then I would use whatever was available (as long as it wasn't outrageously heavy) and not worry about it.

Basically what seems to be important is that the wall be 1.6mm or thereabouts?

[mr henderson]

Basically what seems to be important is that the wall be 1.6mm or thereabouts?


I'm not an expert on the various types of steel available, but I would have thought that what was important was to use a material that was no thicker (and therefore heavier) than it needed to be. If 1.6 if thick enough, then that is the stuff to use, unless it isn't available, in which case use whatever is. If that was (for instance) 3mm then the chassis would obviously be a good deal heavier, but that's better than not building the car at all, much better.

[fluxcored]

I'm not an expert on the various types of steel available, but I would have thought that what was important was to use a material that was no thicker (and therefore heavier) than it needed to be. If 1.6 if thick enough, then that is the stuff to use, unless it isn't available, in which case use whatever is. If that was (for instance) 3mm then the chassis would obviously be a good deal heavier, but that's better than not building the car at all, much better.

Well,I'm still a few months off before starting so I have some time still to ponder the issue.

I'm not getting younger, my health is'nt getting better and my finances are'nt looking too brigth - so if I want to build this thing then I better start in the next couple of months or not at all.

[thwang]

thinking back we used dirty black rhs for some stock car chassis we built years ago and had a chat with my old foreman last night we only used rhs for building breakdown recovery wagons.plus im not thinking of planting it in a wall any time soon.
thwang

[james83mills]

www.wolktv.com or co.uk i got my mig welder for £79.99