Build your own chassis?
Discussion
Did anyone who has built a locost build their own chassis? The book suggests that with a bit of practice anyone could do the job. I really fancy building it from the ground up so would value any opinions on the matter. I have never welded before (well, some oxy at school but that was some time ago) but have always wanted to learn how... how hard can it be ;-)
What the minimum level of power I need to get when purchasing a mig welder in order to do the chassis work?
Thanks,
--
Mark
quote:I'm not sure I understand. Are you saying the home built chassis isn't strong enough or it is more cost effective to buy them ready made? I can't see why a home built chassis shouldn't be just as strong, I grant you it would take practice but I can't imagine mig welding square section steel 'tube' is beyond the skills of many people. As for it being more cost effective I would imagine that if you have the knowledge to build the chassis in the first place you would have the knowledge to cut out the damage and repair it rather than remove everything from your bent chassis and bolt it to your new 400 quid chassis? Thanks for the reply, I was beginning to think no-one frequented these parts ;-) -- Mark
There's a few although given the regular 'bending' of them on the track I personally don't advise it. With Lolowcost and such selling chassis' for around the 400 quid mark it just ain't worth it IMHO.
Well, depending on how you source the materials, I've heard it costs about 250 quid for the tubes alone!
It comes down to confidence, ability and budget. Personally, I felt far more confident in the quality and safety (race chassis) from a professional welding outfit (Martin Keenhan - the best out there IMHO). I only have to look at the welds on my chassis compared to my pigeon poo efforts to see that I made the right decision!
Still, each to their own 
Car No. 13
Car No. 13We built from the book, you _can_ weld up your own chassis, we did in order to use a De Dion rear, but if I were doing it again I'd buy a chassis. The main reason for this is that it's an absolute 'mare trying to get anyone to powder coat one chassis (even in Sheffield) and any other form of coating isn't going to last (I expect lots of arguments on this point. I'm right. You're not 
) Of course if you're going to race every weekend you're going to bend a chassis now and again-in this case don't get your chassis coated, paint it in high zinc paint instead so you can re-weld bits.
If you do buy a chassis ask to see one in the process of being built. Are the tubes cleanly cut ? Are the welds fairly clean when they are made or do they spend ages hacking at them with the grinder ? Does the gal/guy doing the welding have any formal qualifications ? Is the tubing stored indoors in a fairly clean environment (otherwise it will rust) ? If at all possible if you are supposedly getting "book correct" replica of Ron Champion's Locost take the book and check the measurements on a completed chassis. Anyone worth paying will make a straight, dimensionally accurate chassis and will be proud to prove it.
Our chassis had the ultimate test of its welds - my co-builder got side swiped by a Volvo. It survived well, but if I ever build another of these it's DEFINITELY having something solid between the prop shaft and the driver's feet. We fitted an extra diagonal in 1" OD tube (16Gauge I think) down the side of the transmission tunnel but it got squished alarmingly by the shaft, which had been ripped off.
Has anyone out there got any good ideas on this one ? We'd thought about Kevlar, but were put off by 4 figure quotes. What value your legs though ?
Edited by jaydee on Monday 19th November 10:27
) Of course if you're going to race every weekend you're going to bend a chassis now and again-in this case don't get your chassis coated, paint it in high zinc paint instead so you can re-weld bits. If you do buy a chassis ask to see one in the process of being built. Are the tubes cleanly cut ? Are the welds fairly clean when they are made or do they spend ages hacking at them with the grinder ? Does the gal/guy doing the welding have any formal qualifications ? Is the tubing stored indoors in a fairly clean environment (otherwise it will rust) ? If at all possible if you are supposedly getting "book correct" replica of Ron Champion's Locost take the book and check the measurements on a completed chassis. Anyone worth paying will make a straight, dimensionally accurate chassis and will be proud to prove it.
Our chassis had the ultimate test of its welds - my co-builder got side swiped by a Volvo. It survived well, but if I ever build another of these it's DEFINITELY having something solid between the prop shaft and the driver's feet. We fitted an extra diagonal in 1" OD tube (16Gauge I think) down the side of the transmission tunnel but it got squished alarmingly by the shaft, which had been ripped off.
Has anyone out there got any good ideas on this one ? We'd thought about Kevlar, but were put off by 4 figure quotes. What value your legs though ?
Edited by jaydee on Monday 19th November 10:27
I'm building a Formula 27 from plans and making the chassis was the quick and easy part , do it on a level surface , cut acurately , tack ,measure tack again check again , keep tacking on more bits ,in the same way , then when you have a section done like that ,do more welding a quarter of a joint at a time then move to the next to avoid over heating and warping . the key to good mig welding is good preparation ,clean shiney metal makes all the difference , stick welding is more tolerant of rust and paint but the finnish is more dificult to achieve because of slag etc . the ideal mig should be at least 100 amp but 130 or 150 will prove more usefull long term .
go for it
Ps my steel cost me less than a 100 quid and I have some left over , ya pays ya money and takes ya chioce !
go for it
Ps my steel cost me less than a 100 quid and I have some left over , ya pays ya money and takes ya chioce !
well it’s fantastic to see that there are here people with similar interests (dreams?) as me – to build a chassis and make an own kit car.
so let me ask you something else:
-are you using a tubular or a mixed (tubular+surfaces) chassis? (we are projecting a tubular one)
-what steel are you using? (we choose a Cr-Mo alloyed steel)
and thanx for some tips that i already saw here...
>> 4ever roaring
so let me ask you something else:
-are you using a tubular or a mixed (tubular+surfaces) chassis? (we are projecting a tubular one)
-what steel are you using? (we choose a Cr-Mo alloyed steel)
and thanx for some tips that i already saw here...
>> 4ever roaring
We used square section tubing as per "How to build your own car and race it for £250" by Ron Champion. We decided to build a race-spec chassis, with a welded in floor of 16 gauge steel. Heavy, but crash performance was impressive (thankfully, Dieseldrinker wouldn't be the same with no upper body !)
If you're using cro-mo are you brazing or welding ? Brazed joints alledgedly more secure than Mig, but hard to make perfect IMHO.
Try www.geocities.com/MotorCity/7630/
for a radically different approach !
Ron Champion (www.ronchampion.co.uk I think) has a Tig'd aluminium chassis on his site, but for some reason lost half the weight saving through total rivet overkill !
I'll get back to you on what steel we used. CDS but I can't remember anything else about it...
If you're using cro-mo are you brazing or welding ? Brazed joints alledgedly more secure than Mig, but hard to make perfect IMHO.
Try www.geocities.com/MotorCity/7630/
for a radically different approach !
Ron Champion (www.ronchampion.co.uk I think) has a Tig'd aluminium chassis on his site, but for some reason lost half the weight saving through total rivet overkill !
I'll get back to you on what steel we used. CDS but I can't remember anything else about it...
hey, thanx allot for the answer!!
(i have to get that book) yes our objective is to have something really light, and we never thought about that squared section, even in a roll bar for our racer car to the classics championship will be circular, it avoids tensions concentrations.
abou that thing of the crash, man, i don’t care!!!
welding, i’ve been learning to do that in my father’s factory.
again, thanx for the tips and the reply!!
>> 4ever roaring
quote:
We used square section tubing as per "How to build your own car and race it for £250" by Ron Champion. We decided to build a race-spec chassis, with a welded in floor of 16 gauge steel. Heavy, but crash performance was impressive
(i have to get that book) yes our objective is to have something really light, and we never thought about that squared section, even in a roll bar for our racer car to the classics championship will be circular, it avoids tensions concentrations.
abou that thing of the crash, man, i don’t care!!!
quote:
If you're using cro-mo are you brazing or welding ? Brazed joints allegedly more secure than Mig, but hard to make perfect IMHO.
welding, i’ve been learning to do that in my father’s factory.
again, thanx for the tips and the reply!!
>> 4ever roaring
Too right. And furthermore it's bloody good fun.
"our objective is to have something really light, and we never thought about that squared section, even in a roll bar for our racer car to the classics championship will be circular, it avoids tensions concentrations"
Absolutely, but it's v. difficult to make perfectly mating cuts in circular tube without specialist equipment which you may have access to but we didn't...
"our objective is to have something really light, and we never thought about that squared section, even in a roll bar for our racer car to the classics championship will be circular, it avoids tensions concentrations"
Absolutely, but it's v. difficult to make perfectly mating cuts in circular tube without specialist equipment which you may have access to but we didn't...
quote:
...it's v. difficult to make perfectly mating cuts in circular tube without specialist equipment which you may have access to but we didn't...
hi there again,
well actually the chassis wouldn't be properly constructed by only we (a group of 5 21/22 years old guys) but with some (many) help from some my college departments, like the new materials development department, or thermo treatments department.
we have the good luck of to have some people that can help we with will.
we would just project and they would execute the project, but it seems now that we are gonna opting by a construction similar to the F1 cars – that actually isn’t such expensive.
our main 2nd problem is the engine choice, since we would opt for a Alfa 33 1.5 engine/gear box unity, with 137bhp, but that's much heavier than we were thinking about...
hope this gonna get all right.
>> 4ever roaring
quote:
our main 2nd problem is the engine choice, since we would opt for a Alfa 33 1.5 engine/gear box unity, with 137bhp, but that's much heavier than we were thinking about...
You are kidding !!! Surely if your going for an ultralight construction (and you hint at a composite monocoque) then either the toyota turbocharged twink (can't remember the designation-but a quick search for 7 replicas will find discussions of them) or a motor bike engine would make sense. Heck even a k-series would be lighter than this (and give a potential 220bhp.)
Race, that’s the point!!
Jaydee, we know that there are a few different options, but turbo
no thanx. that’s not beautiful!!
the major advantage from Alfa unit is because it’s a boxer 4 cylinders, twin cam and all those things that Alfa knows to do, and it’s copulated to the gear box and differential. it’s also easy to tune the engine, and the unit is really cheap (about 120£) in 2nd hand, as obvious.
so that we would get a mid-engined car, with a good centre of gravity, nice to the curves. which to us, that’s much more important than a powerful engine.
it weight is about 200 kg, and the car shouldn’t overpass the 600 kg. but that would be a two sited car, something like an Exige (but with no wings and much more beautiful and simple), not properly a barchetta.
>> 4ever roaring
Jaydee, we know that there are a few different options, but turbo
no thanx. that’s not beautiful!! the major advantage from Alfa unit is because it’s a boxer 4 cylinders, twin cam and all those things that Alfa knows to do, and it’s copulated to the gear box and differential. it’s also easy to tune the engine, and the unit is really cheap (about 120£) in 2nd hand, as obvious.
so that we would get a mid-engined car, with a good centre of gravity, nice to the curves. which to us, that’s much more important than a powerful engine.
it weight is about 200 kg, and the car shouldn’t overpass the 600 kg. but that would be a two sited car, something like an Exige (but with no wings and much more beautiful
and simple), not properly a barchetta. >> 4ever roaring
Hey V12,
I'm building a mid-engined tube frame car.
www.desicodesign.com/meerkat/
It may be of some interest.
Alan
I'm building a mid-engined tube frame car.
www.desicodesign.com/meerkat/
It may be of some interest.
Alan
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