Hello. I live in Belarus in the city of Minsk. I always very much was interested in automobiles Super Seven, and at last have decided such to construct. Unfortunately I live very far from England and to get ready Kit from England - very difficultly, and transport charges come nearer to cost Kit-car. Now I deliberate above construction of own chassis. Has found on the Internet many drawings. All of them for the chassis from steel. Whether somebody built the chassis of aluminium? There can be someone has drawings of such chassis?

I shall be glad to any advice(council) and the help?

For it is earlier grateful,

Alexander

PS I Ask the application for my English.....

Doh!

Do a search, its been covered 100s of times before on here.

A spaceframe isnt suitable for contructing from ali for many reasons. Low strength and fatigue being the 2 main ones. I cant be bothered to go into lots of detail again!

Make it out of steel, it only weighs about 80kg anyway.

Cheers,
David

PS Welcome to the nut house!

The question of aluminuium being used for chassis construction has been well discussed on this forum.

The general consensus is that it is not a good idea as it will not be very long lasting as fatigue in the joints and suspension mounts could be an issue as the miles rack up.

Steel is generally thought to be the preferred material although Robin Hood have started making the lightweight kit which is an Aluminium chassis

Have a look here http://www.robinhoodengineering.co.uk/Bolteon.htm

Hope that helps

Mark

Hello, and welcome!

You are correct: the chassis for seven type vehicles is normally made from steel, as Aluminium suffers fatigue, and can break after time.

As FlakMonkey says: make it out of steel, as the lower strength of Aluminium will mean making it out of thicker material, which will increase the weight, so the amount of weight you save will be small.

Hope this helps,

Ed.
P.S. For reference, steels are 7800 KG/M^3, pure Aluminium is 2700 KG/M^3.

Looks like we are now covering all 4 corners of the globe now

To answer your question if you do a search on here you will find that this idea and the pro and cons have been covered before.

The general concensus of opinion is that it's really not practical to use alu for a sevens spaceframe.

Very much, very much, it is very grateful.
Thanks for the answer.
Recommend, please, drawings of the chassis. Those drawings which it is possible to take and build safely the Locost.

Thanks.

Who knows, what it is the automobile who it built? Or it built on Donkervoort?Image deleted by owner

That pic is of a Donkervoort. Good if you have the money I guess.

The McSorley plans (link on the links page of this site) are the best ones to use to build the chassis apparently.

David

Thanks, David.
I shall necessarily study these drawings.
I have visited your site. I liked your work.

It is glad for you, Success.

Alexander.

Is Estfield not more in your region?
Or I heard something of a kitcar manufacturer in Finland.

Have a look in the running gear section for plans from Rorty for both IRS and DeDion to fit the standard chassis and Sierra running gear

What car will U use for donor Ruders, I was thinking about LADA but don't know is it possible

Lada has been done by at least one builder who has built several chassis --- no major problems apparently

see http://www.racetech.ee/

The engine - Zetek, other sites - Ford Siera/Lada

Lada - not the best automobile as a whole.

Now at me a problem with wishbones. I yet have not found their drawings. Also I do not know as they incorporate to a nave of a wheel. In the Internet I have found drawings of the chassis with a dependent back suspension bracket. I search - independent, while for it for me a problem.

Hi Ruders,

You need to buy the locost book:

http://www.amazon.co.uk/exec/obidos/ASIN/1859606369/qid%3D1139926895/202-3477024-6266263

That'll give you the plans that we all use for wishbones, chassis, etc. etc. Just use the McSorley plans to correct the chassis plan mistakes!

Cheers,
James

Is Estfield not more in your region?
Or I heard something of a kitcar manufacturer in Finland.

Interesting that. I wondered what happened to all the rusty old Ladas. Like why the Russians started shipping them back to Mother Russia. A Lotus Riva is possible then.
Also think of the potential weight saving. Junk the starter motor and battery and replace with the starting handle.

Is Estfield not more in your region?
Or I heard something of a kitcar manufacturer in Finland.

Interesting that. I wondered what happened to all the rusty old Ladas. Like why the Russians started shipping them back to Mother Russia. A Lotus Riva is possible then.
Also think of the potential weight saving. Junk the starter motor and battery and replace with the starting handle.

Do not underestimate Laa 1500ccm has 80HP and if you lighten the flywheel and put two carburators it will run very nice. That is Fiat engin maybe old but stil fiat.

I long pottered with motors Porsche 944/924. I saw their design, I assorted them and collected the hands. And now in my garage it is possible to find a heap of details from these motors. And consequently I know, (I think, that I I know) what should be the motor. It is exact should not LADA! Racing motors LADA - are very good! But their price is very high. And it is completely not similar to factory motor LADA. Besides I test sympathy to mark FORD. My the first car was FORD Escort 1.6 xr3i 1983. It was the delightful automobile. At us in the country strongly underestimate mark FORD. It count budgetary and confused, completely not sports. I want to prove the opposite.

The Fiat 124 was delightful car to drive --- it would disapear into a pile of rust in the UK climate within 2 years and had dogey itailan electrics but it was lively, handled a treat and very nice to driver.

The Lada was in theory a toughened up 124 but had none of the joy of driving the the 124 had, the bulid quality was truly awful and the materials used were substandard.


Only thing worse was the Polski-Fiat 125 that was a contender for the worst car in the world award along side the Zodiac Mk4, Chrylser 180, Austin Allegro.

The Fiat 124 was delightful car to drive --- it would disapear into a pile of rust in the UK climate within 2 years and had dogey itailan electrics but it was lively, handled a treat and very nice to driver.

''The Lada was in theory a toughened up 124 but had none of the joy of driving the the 124 had, the bulid quality was truly awful and the materials used were substandard.''
Yup the Lada was truly awful and the FIAT not half bad. Steering worst thing on Ladas. Not rack and pinion. Lada should have left original design alone.

The Fiat 124 was delightful car to drive --- it would disapear into a pile of rust in the UK climate within 2 years and had dogey itailan electrics but it was lively, handled a treat and very nice to driver.

''The Lada was in theory a toughened up 124 but had none of the joy of driving the the 124 had, the bulid quality was truly awful and the materials used were substandard.''
Yup the Lada was truly awful and the FIAT not half bad. Steering worst thing on Ladas. Not rack and pinion. Lada should have left original design alone.

Hi

I'm the proud owner of a Locost7 Fireblade with an aluminium chassis.

The chassis has been rock solid for the last 5 years without any signs of cracking.

When I built it I had everyone and their mother saying it would not work....it will crack (it has not), it will bend(no), it will be hard to make(it was easy)...you get the picture.

The chassis is taken directly from the original book design with some strengthening around the suspension mounts. The Fireblade unit is mounted rigidly with an FR2000 reversing box in the tunnel.

I have had one or two small problems with attaching items like body mounts and fixings to the chassis. I welded on small tabs then bolted things on to them, a couple of these tabs have fallen off due to fatigue cracks.

The chassis has been periodically crack tested without incident.

Julian
Rescued attachment P4290016.JPG

just out of interest, what is the weight of your car julian?

quote:

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Originally posted by JulianT
The chassis has been periodically crack tested without incident.

---

I'd guess Dye Penetrant Crack Testing.

Testing the whole car would be expensive, but doing localised tests in high stress areas (suspension mounts etc) would be managable.

quote:

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Originally posted by andyps
Have a look in the running gear section for plans from Rorty for both IRS and DeDion to fit the standard chassis and Sierra running gear

---

I'm glad it has been reliable. Apparently the engineers calculated the proper material thickness to prevent cracking - so far. But one chassis lasting five years doesn't mean an aluminum chassis is an easy, no-brainer, to be built same as a steel one.

Based upon what I've read, I will never make an aluminum chassis. I wonder what the torsional stiffness is of that one. Regardless, it's not an issue about *if* it will crack, but when, because it will. Hopefully it will be after you've sold it, so make sure any future buyer is aware.

There is a very good reason aluminum aircraft fuselages are removed from service at some point - the engineers knowing when it has become unsafe. Porsche experimented with aluminum race car chassis, and gave up on them. These two groups know what they're doing, and we don't...

quote:

---

Originally posted by JulianT
Hi

I'm the proud owner of a Locost7 Fireblade with an aluminium chassis.

The chassis has been rock solid for the last 5 years without any signs of cracking.

When I built it I had everyone and their mother saying it would not work....it will crack (it has not), it will bend(no), it will be hard to make(it was easy)...you get the picture.

The chassis has been periodically crack tested without incident.

Julian

---

Dear KB58

I'm an aircraft engineer by trade, working on commercial and military transports. Every aircraft, irrespective of construction has a series of inspection or service points in it’s life. These points are based on flight hours, landings or specific incidents (perhaps a heavy landing). As each point is reached different inspections are required. An aircraft can go on indefinitely as long as the rules are followed, it’s generally certain components or locations that are very carefully checked and if required replaced. As an example hundreds perhaps thousands of WW2 aircraft are still happily flying. Currently I’m working on an aircraft called a Nimrod, it’s basically a 1950’s Comet airliner that had been modified as an anti submarine aircraft, it has been in UK military service ever since. We are rebuilding it for about the fourth time.

I’m certainly not going to recommend that aluminium is the way to go, I’m not even going to recommend it to anyone, it is however quite possible if you know what you are doing. You are very right to say people should not try it. My point is that I’m constantly amazed by the half truths presented as fact on this subject, every material has it’s ups and downs. My car and a dozen others I know about show it can be done – as long as you know the rules.

If you want to see something really scary, just go to a kit car show and walk round the public car park and look at the welding on some of the home made steel chassis.

I’ve had the welding X-ray’d a couple of times after construction and used an ultraviolet process since. A local aviation college is very happy to do it for free, they use it as a training exercise for students.

All the best Julian

Car looks very nice indeed, and welcome to the forum...

Out of interest what grade of ally have you used and what wall thickness is it? Do you know what it weighs and how stiff it is? Sure you can overcome the disadvantages of using this relatively 'difficult' material with the right knowledge, careful fabrication and constant rigorous checking, but have you actually gained any advantage with an ally copy of the book locost not-particularly-good-steel-spaceframe to make it worthwhile?

Liam

[Edited on 17/8/06 by Liam]

quote:

---

Originally posted by JulianT
it is however quite possible if you know what you are doing. You are very right to say people should not try it. My point is that I’m constantly amazed by the half truths presented as fact on this subject, every material has it’s ups and downs. My car and a dozen others I know about show it can be done – as long as you know the rules.

Julian

---

KB i can get most of that for you in the morning. Other than how long it will last.

To compare the mass of steel to ally, multiply steel thickness by 8.07 to get a factor, and the ally by 2.73.

so 1.6 x 8.07 = 12.9

12.9 / 2.73 = 4.72.

so for the same mass you can use 4.7 mm ally or 1.6 steel

The mass of a block of steel would be L (in metre) x W (in metre) x thickness (in millimetre) x 8.07 = KG

Cheers

Fred W B

[Edited on 18/8/06 by Fred W B]

JulianT how much does your car weigh? its got to be LIGHT! Nice looking car too!

Steel is stronger than aluminum.
Aluminum is stiffer than steel.
Steel is more elastic than aluminum.
Aluminum boesn't bend it snaps and generally at the weld.

I did some rough weight caculations for steel and aluminum chassis.

STEEL - 1"sq x .06wall x 12"lg = .76lb/ft x 120' = 91lb (41kg) frame

STEEL - 1.25"sq x .06wall x 12"lg = .97 lb/ft x 120' = 116lb (53kg) frame

ALUMINUM - 1"sq x .06wall x 12"lg = .26lb/ft = 31lb (14kg) frame

ALUMINUM - 1"sq x .13wall x 12"lg = .53lb/ft x 120' = 64lb (29kg frame

ALUMINUM - 1.25"sq x .06wall x 12"lg = .33lb/ft x 120' = 40lb (18kg) frame

ALUMINUM - 1.5"sq x .10wall x 12"lg = .66lb/ft x 120' = 79lb (36kg) frame

[Edited on 8/18/06 by KENLUDE97]

ahh the good ol' ally frame discussion again!

Funny when this keeps coming around, and everybody divides into the "it'll snap in half" and the "its really cool and light" camps!!

At some point somebody will realise that building a "locost" chassis from welded ally box is like building a cathedral from expanded poystyrene or inventing a titanium steam powered beam engine................................

Use the technology to its advantage, don't apply it to a design not meant for that material.

This is one occasion where I will mention Robin Hood cars without criticising too much, as their "cheesegrater" was actually an attempt to use ally properly in a "7 type vehicle"

I suggest a good look at the construction techniques used in the Lotus Elise and the monocoque Lolas would be a good starting point.

For a starter for ten......there aint any welds!

quote:

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Originally posted by JulianT
Dear KB58
Currently I’m working on an aircraft called a Nimrod, it’s basically a 1950’s Comet airliner

---

we once had a f27 alloy chassis at our workshop, made from 40mm od x 2.5 wall durol with 4mm gusset plates etc, the problem was that the size of the tubing meant two things
1. the cockpit space was tiny im only 8 1/2 stone and 5 foot 9 and i could barley fit in
2. it was 20 kilos heavyier than a fully triangulated steel chassis with full t45 cage ( did look impressive though ) apparantley they only made three due to costs and the fact is was heavier than the the steel spaceframe.

How old are you ? 12. . How much does aluminium tube cost compared to steel of a comparable strength and can you weld it with a £200 mig running cheap co2 cylinders? That is the only consideration for a Locost in my estimation. If it's going to cost more to buy and more to build it's defeating the object of the excercise. edit:-
Just a question for you Julian, how many miles has it done in the 5 years on the road? It's not done many in the picture from the rust on the disks.

[Edited on 19/8/06 by Peteff]

quote:

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How old are you ? 12. .

---

Same here, except same since I was 15 and it's been 6'3" and 14 1/2 stone! Plenty of space in my car!

quote:

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Originally posted by kb58

quote:

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Originally posted by JulianT
Dear KB58
Currently I’m working on an aircraft called a Nimrod, it’s basically a 1950’s Comet airliner

---

Wasn't the Comet the aircraft where several crashed and the cause traced to not understanding metal fatigue? As I recall it was the pressure cycling as the aircraft climbed to altitude and down again. They finally found it by filling a fuselage with water(!) and cycled the pressure. The lead engineer was called late one night, "I think you better come look at this." The fuselase had indeed split. It marked the death of British airliners because by then the US builders had watched and learned what had happened, then come out with thier own fleet.

Anyway, the irony here is that we're discussing metal fatique and you brought up the one aircraft that made metal fatique famous.

[Edited on 8/18/06 by kb58]

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Thanks, yeah I almost didn't post that, afraid it would start some defensive "lively" discussion.

Since we are discussing aluminum metal fatigue though, it's sadly a perfect example of the consequences of using aluminum without knowing the qualities of the material. And most of us don't either, myself included...

[Edited on 8/21/06 by kb58]

The chassis is made of an Ali alloy - 7075, it has zinc and copper added. The welding was not done by me. The tubes were pri heated in a oven before welding.
The tubes were left over from an MOD project so cost nothing (in true Locost fashon). The car weighs 350kgs and has done 3800 miles. Standard 120hp 893cc Fireblade.
Rescued attachment I~0000772.JPG

Hi Julian

This brings back memories, I think it was yourself who invited me over for a nose around your car about 5 years ago before I started building mine!!

I must say Ive always been slightly concerned with the straight transfer of design from steel to alu, but glad to see it has survived and is still going strong. IIRC this was the alu chassis built by Ron Champion wasnt it, with thicker wall tube than a steel equivalent chassis? Sorry if I've sistaken you for someone else, but Im sure it was around the Newbury area and it was definitely a silver alu chassis'd Locost, so there can't be too many of you!

All the best

Chris

[Edited on 27/8/06 by ChrisGamlin]