Microcars and lightcars in Europe

Microcars and lightcars in Europe

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fuoriserie

Original Poster:

4,559 posts

233 months

Sunday 3rd February 2013
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Mistrale said:
Only one word:

W O W !

Thanks for sharing that link.
You're welcome...smile


Italo

fuoriserie

Original Poster:

4,559 posts

233 months

Wednesday 13th March 2013
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robcollingridge

480 posts

247 months

Wednesday 13th March 2013
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Looking to design and build a 400Kg sports car as soon as I can:
http://www.robcollingridge.com/400kg/



Rob

ugg10

681 posts

181 months

Wednesday 13th March 2013
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Rob - may be worth looking into sandwich structure monocoques + bike engine (which I know you sre familiar with). Specifically have a look at rohacel as the core (expensive, best strength but can't be formed easily so good for flat panels) with either glass of carbon fibre skins. If you can get the three parts bonded well together then it will produce a very stiff structure with surprisingly low weights. This has been used in the past in the formula student class I think.

Always thought that you could re-engineer the classic seven shape this way (lots of straight lines, think take the tubular shape, fill inbetween the gaps with the core, take awsy the steep structure and cver with GRP/CRP). Two brothers who built racing yachts from Ringwood/Salisbury area looked into this a while back but think it was not progressed, thier other car, which is one of my favourite kit cars, was the Structural Engineering Larini. I think this was later taken on by GTM but was priced pretty high. See scan of an old advert that may be of help.



Edit - Formula Student car was the 2004 Brunel car with chassis (carbon fibre and aluminium honeycomb sandwich) made with help from QinetiQ (my employer) and weighed only 14kg, the Larini became the GTM Ballista which was resold into obscurity on ebay in 2009 I think.

Also I guess you have seen Jeremy Philips J15/16, www.sylva.co.uk, I would suggest you give him a call as he may be interested in the project and could help with chassis design I guess.

Finally, love the picture, original F type prototype IIRC from a few years back also reminds me of the Lightning car http://greencarsite.co.uk/comingsoon/lightning-car... If you scale this down to Fury size and make it rear engine then you get something like the Costin's last cars (specialist automotive I think) - http://www.minimarcos.org.uk/shows/detling06/p06.j... - you wouldn't go far wrong with that as your starting point (or the J15). J15 Lightweight body with a sandwich monocoque, ally uprights and wishbones and an r1 engine would be something to behold !

Edited by ugg10 on Wednesday 13th March 20:58


Edited by ugg10 on Wednesday 13th March 21:09

mad4amanda

2,393 posts

128 months

Wednesday 13th March 2013
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Remember in france one of the reasons they are so popular is that they can be driven without a car licence (ligier, axiom et al) so are particlarly useful if say youve been banned from driving for drink drive! several of my outlaws neighbours have them for this very reason.

qdos

825 posts

174 months

Wednesday 13th March 2013
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mad4amanda said:
Remember in france one of the reasons they are so popular is that they can be driven without a car licence (ligier, axiom et al) so are particlarly useful if say youve been banned from driving for drink drive! several of my outlaws neighbours have them for this very reason.
They are though limited to a maximum of 15kW or 21 horse power to us oldies

rdodger

1,074 posts

167 months

Wednesday 13th March 2013
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robcollingridge said:
Looking to design and build a 400Kg sports car as soon as I can:
http://www.robcollingridge.com/400kg/



Rob
That looks a great project Rob. I look forward to developments.

TheLastPost

1,150 posts

105 months

Wednesday 13th March 2013
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ugg10 said:
Specifically have a look at rohacel as the core (expensive, best strength but can't be formed easily so good for flat panels) with either glass of carbon fibre skins. If you can get the three parts bonded well together then it will produce a very stiff structure with surprisingly low weights.
You pays your money and you takes your choice, where sandwich panel core materials are concerned - there are a large range, with different properties to suit different applications - but AIUI Rohacell isn't well suited to the panel being routed and folded, as can be more easily achieved with most of the expanded honeycomb-type core materials (which means it isn't suitable for one of the easiest ways of dealing with corner junctions). Honeycomb core materials (typically aluminium or Nomex) may be a better option, in this respect.

You can buy ready-made panels, if you wish, which avoid most of the production and quality control complications you get when 'rolling your own' by bonding the cores and skins together yourself.

ugg10 said:
Always thought that you could re-engineer the classic seven shape this way (lots of straight lines, think take the tubular shape, fill in between the gaps with the core, take away the steel structure and cover with GRP/CRP). Two brothers who built racing yachts from Ringwood/Salisbury area looked into this a while back but think it was not progressed...
It's been done more than once by Martin Ogilvie (ex-Lotus F1 Chief Designer, responsible for one of the very first Formula One carbon monocoques, the Lotus 87/88, which was manufactured by the route-and-fold technique from honeycomb core sandwich panels). He was responsible for a couple of 'Seven' style cars in the form of the Wisper and the (slightly) better known Westfield FW400, both of which used essentially the approach you describe in terms of their basic structure.

mad4amanda said:
Remember in france one of the reasons they are so popular is that they can be driven without a car licence (ligier, axiom et al) so are particlarly useful if say you've been banned from driving for drink drive!
There are other restrictions beyond weight to qualify to be driven without a licence though - only vehicles in the 'Light Quadricycle' class (maximum 350kg, max speed 28mph, max. 50cc spark ignition/5.6bhp engine) can be driven with no licence whatsoever (if you're old enough). 'Heavy Quadicycles' (up to 400 kg and a tarmac-rippling 22bhp) qualify to be driven on a motorcycle licence, I think?

In either case, I suspect that Rob will be seeking slightly higher levels of performance. wink



ETA: There was also some interesting discussion around Rob's project when he announced it on this thread, last year.

Edited by TheLastPost on Wednesday 13th March 21:39

ugg10

681 posts

181 months

Wednesday 13th March 2013
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Thelastpost - thanks for the comments and I agree with you. The rohacell is good in flat panels (pretty well the best) and so could be used for a chassis under a GRP body. It can be thermo formed but not very easily and only over large radii. But as you say it is probably better to use Aluminium or Nomex for the core with shaped panels and you can get significant stiffness from just using EPS or poleurathane foams aswell. Also the benefits of using CRP vs GRP are not that much particularly taking into account the difference in cost i.e. GRP skins with EPS is pennies to make and not far off the performance of CFR with Rohacell which is tens, if not hundreds of pounds. The big trick seems to be ensuring you have a 100% bond between the skins and the core, interestingly, if you do this then you can cut holes in it without loosing much strength/stiffnesss, even better if you engineer the holes and encapsulate the core as well. And finally, you can encapsulate ally structures in the core to give suspension mounts etc. integrated into the structure, very neat.

Thge larini was interesting in that it has a central sandwich monocoque with steel/ally frames mounted off the front and rear bulkheads for the rear engine/suspension and front suspension. The idea was to have a rear frame you could quickly swap depending on the application e.g. as it was mk2/3 VW golf based, 1.8 16v gti engine for road + VR6 for trackdays. Another idea to throw into the pot for Rob.