russbost
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| posted on 29/10/15 at 08:22 AM |
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Sam
re "I'd definitely be doing the tub in route-and-fold sandwich panels, though: the design and fabrication of a '60's-style
single-seater tub in this material is really simple." although it's obviously totally "out of period" with regard to the
original type of car, can you explain a little more about this type of construction, it's not something I've ever had much to do with,
about the nearest I got was owning a Pulsar lightweight plane which had a form of honeycomb composite construction - any links to websites for
materials/suppliers or info would be handy
"Funny how many people I've come across through the years who've wanted this sort of single-seater road car. There's got to be
an unexploited market for a simple design, out there... maybe needs to be my next project." - well, I don't do shows anymore, however when
I was doing so if I had a fiver for every picture taken of my car & every person who told me what a great idea it was & brilliant to be
different from all the 7's, etc etc blah blah blah then I'd be a very rich man indeed, as it is fortunately it was never intended to be
anything more than a hobby business & we are now on chassis no.17 (+1 if you count the original car). Many people seem to like the versatility to
be either a single seater or twin depending if "air box" is off or on - something you couldn't do with the 32B without going miles
outside the original dimensions. Much talk has never translated into sales & loads of people talked about the Formula Ford that Ford put on the
road, that exact car is now being sold in the States, but it looks like the price tag is going to be probably around £60k, I can't imagine there
being too many takers, but good luck to the sales team if they can make it fly away.
I think for it to sell it would have to be very, very cheap & as you say, very simple, can't see how you could make a business plan out of
that? I know who has the Edge Devil moulds & chassis now - I think it sold a total of 5 chassis, not all of which are on the road ............. It
does have some major design floors in the aerodynamic department at much over 70Mph, but that could fairly easily be sorted.
Russ
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Ugg10
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| posted on 29/10/15 at 08:43 AM |
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Here is another to add to the reference list - slc nemesis from the USA.
http://superlitecars.com/index.php/cars/nemesis#1728-carlisle_06
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
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tul214
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| posted on 29/10/15 at 09:49 AM |
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No-one has mentioned this
NTDWM and not sure that it is still for sale but it may help?
1.6 Raw Super6 sold
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paddywil
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| posted on 29/10/15 at 10:36 AM |
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Haha no worries, I should have put a picture up earlier!
Whichever engine I end up with, it's going to be a straight four, right sounds and it will fit. I'mean starting to think the route and
fold option is going to be the way to go, seems like a pretty simple construction method
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Neville Jones
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| posted on 29/10/15 at 10:36 AM |
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quote:
Originally posted by Sam_68
quote:
Originally posted by Ugg10
Remember the beetle has the engine behind it so if you are looking for mid endine then the gearbox will need flipping and so may need things like oil
vents/feeders/plugs etc. reworking...
With the Beetle box, you just flip the crownwheel from one side to the other. No need to invert the whole box.
quote:
Originally posted by Ugg10
....have you thought about making the monocoque out of a composite sandwich structure using woven fabric skins (getting the weave directions right
between the layers is the key) and a polyeurothane foam core (Rohacel is the gold standard but expensive), this could produce a very light and stiff
tub and does not have to be too expensive. Subfrmaes can then be bolted onto the front and rear to hold the oily bits and has the potential, with
quick release plugs/lines, to allow quick changes of the rear engine cradle. This was used in the Scultpural Engineering Larini (later the GTM
Ballista) and is used in Yacht building.
Personally, I'd go for routed-and-folded pre-manufactured composite sandwich panels, as per the early Lotus F1 carbon tubs and Westfield WiSPER.
Much lighter and more consistent quality than trying to 'roll your own' with wet layup. Pre-manufactured panels, such as Cellite, will
usually have aluminium or nomex honeycomb cores, which are more suited to automotive use.
Routed-and folded aluminium sandwich panels (as described in Tony Pashley's M/C Engined race car book) are an option too - and certainly better
than a single-skin aluminium monocoque.
If you flip the beetle 'box, it puts the engine in front and turns the wheels the right way, AND puts the outputs up high, which puts the engine
down low, just where the racers put it. And no crownwheel setup problems. VW van and Transporter 'boxes can be used as well, and have been
attached to V8's.
Can you post pics of chassis that YOU have built with this method, Sam?
[Edited on 29/10/15 by Neville Jones]
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paddywil
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| posted on 29/10/15 at 10:41 AM |
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Out of interest, what is used to adhere the folded panels to each other in the route and fold method?
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paddywil
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| posted on 29/10/15 at 10:44 AM |
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quote:
Originally posted by Ugg10
Here is another to add to the reference list - slc nemesis from the USA.
http://superlitecars.com/index.php/cars/nemesis#1728-carlisle_06
Another one that I have seen before, looks like a lot of fun though!
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paddywil
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| posted on 29/10/15 at 11:13 AM |
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If anyone wants to know more about building a chassis using the sandwich panels, this makes an interesting read
http://www.tech.plym.ac.uk/sme/acmc/download/chass.pdf
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russbost
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| posted on 29/10/15 at 11:48 AM |
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quote:
Originally posted by paddywil
If anyone wants to know more about building a chassis using the sandwich panels, this makes an interesting read
http://www.tech.plym.ac.uk/sme/acmc/download/chass.pdf
It does make interesting reading, but I'm really struggling to see how this method can be used to make the sort of complex curves on something
like the 32B - am I missing something here?
The Pulsar plane I owned had a considerable amount of complex curves, that was, I believe made from a fibreglass honeycomb of some sort, I would
assume this type of structure is resin soaked & forced into a mould much like a wet layup system? I can't see otherwise how you would get
the curved & tapered shape? It was supplied to builders as 2 halves much like an Airfix plane, but you only had to join the 2 halves, there was no
shaping involved after the initial factory supply.
Neither of the above are going to lend themselves to construction of a one - off monocoque so far as I can see, I would have thought it much better to
KISS & stick to laser cut aluminium or steel sections to make internal "bulkheads" for areas of high strength/stiffness, such as the
suspension, engine & steering column mounting areas, make a very basic wooden "chassis" as a former & then roll, bond & rivet
the alloy panels around this, then remove the wood & fit the "bulkhead" sections in place again bonded & rivetted, note this is
surely going to need "proper" rivets - I don't see pop rivets doing the job here. The original cars were only a monocoque as far as
the front bulkhead where the master cylinders were mounted & the rear bulkhead where the engine was bolted in as a stressed member (certainly on
later cars with the Cossie DFV, not sure if earlier cars like the 25 & 32B used the engine as a stressed member or if it was carried in some form
of subframe with the suspension attached which was the bolted up to the rear of the monocoque?)
There would be a lot of work in making it this way, but would cost very little in materials
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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paddywil
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| posted on 29/10/15 at 12:04 PM |
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As far as I understand this, the structural component of the car would be constructed from the honeycomb, the curved bodywork would then be fabricated
separate, and attached to this structural section...
Both methods have a lot of advantages, so I shall have to have a think. My original plan was to construct the monocoque from just sheet aluminium,
assembled as per the original. If i go down this route, I'm planning on using 'real' rivets on most joints, only using POP rivets on
blind joints.
This would be a fairly easy method of construction, assuming I built a jig to hold the pre-cut panels, then could simply rivet/bond them together.
Im not sure whether the original used the engine as a stressed component, but in this case I don't plan on doing so - I'm thinking of
using a steel tubular structure to hold the engine and support the suspension, which would them bolt to the monocoque
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paddywil
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| posted on 29/10/15 at 01:17 PM |
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I've made a full size mock up of one of the transverse 'ribs' of the monocoque using a rough set of dimensions, seems fairly
satisfactory for driver comfort...
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Sam_68
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| posted on 29/10/15 at 01:41 PM |
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quote:
Originally posted by russbost
It does make interesting reading, but I'm really struggling to see how this method can be used to make the sort of complex curves on something
like the 32B - am I missing something here?
The main thing you're missing, I think, is that you don't need complex (ie. compound) curves.
Some 60's formula car tubs - for example the Lotus 27 - had simple, single-curvature sill panels (ie. on plan view, the sides were straight)
This is a Lotus 27 tub:
quote:
Originally posted by russbost
The original cars were only a monocoque as far as the front bulkhead where the master cylinders were mounted & the rear bulkhead where the engine
was bolted in as a stressed member (certainly on later cars with the Cossie DFV, not sure if earlier cars like the 25 & 32B used the engine as a
stressed member or if it was carried in some form of subframe with the suspension attached which was the bolted up to the rear of the monocoque?)
Only the 49 and onwards used the engine as a stressed member (indeed, apart from the first use of the DFV engine, that was the 49's main
innovation). From the 25 to the 49, the tub extended beyond the rear cockpit bulkhead, as can be seen on the above pic.
You need to be slightly careful about using this approach in composite skinned sandwich panels, as they don't have a good tolerance to very high
temperatures.
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paddywil
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| posted on 29/10/15 at 02:12 PM |
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Thanks for the pic - very useful to see a tub in its naked state!
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russbost
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| posted on 29/10/15 at 03:40 PM |
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Ah! I know what I was forgetting, just how low & bl**dy lethal those old tubs were, Geez, that's barely hip height! I'd forgotten that
they didn't go up around the steering & front suspension bulkheads at all - so, yes, I can see now how that method could be used.
I have to say I'm not happy in a 7 with it's lack of side protection, I would be totally unhappy in a tub like that! & I also
didn't remember the tub extending back to carry the engine & rear suspension, I thought that prior to stressed engines that was all carried
on a subframe - I must be too young! 
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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paddywil
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| posted on 29/10/15 at 04:47 PM |
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quote:
Originally posted by russbost
Ah! I know what I was forgetting, just how low & bl**dy lethal those old tubs were, Geez, that's barely hip height! I'd forgotten that
they didn't go up around the steering & front suspension bulkheads at all - so, yes, I can see now how that method could be used.)
I must admit, I Wouldnt want to hit anything in one of these!
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Sam_68
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| posted on 29/10/15 at 06:38 PM |
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quote:
Originally posted by russbost
I have to say I'm not happy in a 7 with it's lack of side protection, I would be totally unhappy in a tub like that! & I also
didn't remember the tub extending back to carry the engine & rear suspension, I thought that prior to stressed engines that was all carried
on a subframe - I must be too young!
Well, each to their own, and I freely admit that I'm nothing like as risk averse as some of these youngsters who won't go anywhere near a
'Seven' unless it's got a full cage with side intrusion bars...
...but on a 'Seven', you have a 1" steel tube, pretty much touching the side or your torso, that will deform and stay
deformed in the event of any significant side impact.
With a sandwich panel tub, you've potentially got a 9" wide triangular section torsion box, made of a material that doesn't
permanently deform, but does absorb an immense amount of energy as it progressively collapses (the honeycomb holds everything together, so the
carbon/grp skins disintegrate in a very linear, progressive manner in an impact... that's why they make crash boxes out of the stuff for race
and supercars).
If you're of a particularly nervous disposition, you could also fill both the triangular section torsion box, and the gap between the outer face
of the torsion box and the curved, cosmetic outer skin with expanding foam, for only a little additional weight penalty.
Or you could buy a Volvo.
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russbost
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| posted on 29/10/15 at 07:04 PM |
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"you've potentially got a 9" wide triangular section torsion box"
Eh? How do you compute that one in a single seater??? I'm reasonably slim & sitting down I'm around 16" across the hips, allow
2" each side for some clearance to get a seat, handbrake & gearlever in (still pretty tight), then add your 9" each side & your
single seater is now a minimum of 38"- that's the widest 32B I've ever seen!!!
Not disputing the impact absorbing abilities of foam & fibreglass/aluminium honeycomb, but what would concern me a lot more is that the whole of
my upper body has the protection of .............Errrrr............. a 3mm thick piece of fibreglass or similar!
When I'm sitting in the middle of my Furore I have impact protection to front, rear & both sides, the chassis extends to around my shoulder
height & unless I submarine under the back of a truck (in which case I might be headless! - some would say, no loss!) I'm reasonably safe.
Let's face it, if you connect with a truck whatever you're driving you are going to come off badly. But in a tub such as that pictured
(I'm assuming that anything above the height of the tub would be a thin fibreglass structure largely there for cosmetic & aerodynamic
properties) if you were hit by anything larger than a squirrel whether on 2 wheels or 4, you are going to have a pretty major problem unless it hits
you square on the rear & even then you may find you are now part of the engine!
I'm not terribly risk averse, but would not be in a hurry to ride a motorbike nowadays, I would put a tub such as that in a similar bracket to
a bike as regards safety. I know it might not be "in period" - but then neither is honeycomb construction - but I think I'd want a
fair bit more in terms of a top half of the tub!
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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russbost
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| posted on 29/10/15 at 07:05 PM |
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"you've potentially got a 9" wide triangular section torsion box"
Eh? How do you compute that one in a single seater??? I'm reasonably slim & sitting down I'm around 16" across the hips, allow
2" each side for some clearance to get a seat, handbrake & gearlever in (still pretty tight), then add your 9" each side & your
single seater is now a minimum of 38"- that's the widest 32B I've ever seen!!!
Not disputing the impact absorbing abilities of foam & fibreglass/aluminium honeycomb, but what would concern me a lot more is that the whole of
my upper body has the protection of .............Errrrr............. a 3mm thick piece of fibreglass or similar!
When I'm sitting in the middle of my Furore I have impact protection to front, rear & both sides, the chassis extends to around my shoulder
height & unless I submarine under the back of a truck (in which case I might be headless! - some would say, no loss!) I'm reasonably safe.
Let's face it, if you connect with a truck whatever you're driving you are going to come off badly. But in a tub such as that pictured
(I'm assuming that anything above the height of the tub would be a thin fibreglass structure largely there for cosmetic & aerodynamic
properties) if you were hit by anything larger than a squirrel whether on 2 wheels or 4, you are going to have a pretty major problem unless it hits
you square on the rear & even then you may find you are now part of the engine!
I'm not terribly risk averse, but would not be in a hurry to ride a motorbike nowadays, I would put a tub such as that in a similar bracket to
a bike as regards safety. I know it might not be "in period" - but then neither is honeycomb construction - but I think I'd want a
fair bit more in terms of a top half of the tub!
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Sam_68
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| posted on 29/10/15 at 07:31 PM |
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quote:
Originally posted by russbost
"you've potentially got a 9" wide triangular section torsion box"
Eh? How do you compute that one in a single seater??? I'm reasonably slim & sitting down I'm around 16" across the hips, allow
2" each side for some clearance to get a seat, handbrake & gearlever in (still pretty tight), then add your 9" each side & your
single seater is now a minimum of 38"- that's the widest 32B I've ever seen!!!
Well, you omit the 2" each side clearance, for a start. 100mm. wider than you need in a formula car cockpit?! 
You don't need any significant clearance, beyond a couple of neoprene pads to cushion your hips. And Colin Chapman's
'compressibility of bums' theory extends to compressibility of hips, too. Handbrake and gearlever mount into the top faces of the torsion
boxes (as the gearlever did on original '60's formula cars, of course).
But yes, the tub I've designed is not quite as narrow as a 27; nor is it a direct replica of the 27, or anything else... though it's a
damn sight closer than the Gordon Murray Rocket, for example.
And on checking my drawings, you're right - it's 7" rather than 9" for the torsion boxes on my current design - but I did say
potentially
quote:
Originally posted by russbost
...what would concern me a lot more is that the whole of my upper body has the protection of .............Errrrr............. a 3mm thick piece of
fibreglass or similar!
Better than the thin air (with your elbow projecting out the side!) that you get on a traditional 'Seven'?
As I said, each to their own... but I respectfully suggest that if you're that bothered about secondary safety, you're in the wrong
business entirely.
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paddywil
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| posted on 29/10/15 at 09:09 PM |
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Im pleased to see how much thought everyone puts into their safety, and mine! I have no expectations of this being a safe car, but I would say that
from a side impact I see there being relatively little protection, although I dont consider a 7 to be safe either!
I think that there could definately be some effort put into front/rear impact protection, but chances are in something this low I'll be going
under whatever i hit 
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paddywil
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| posted on 30/10/15 at 09:26 AM |
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Despite their use on many self build and kit cars at the moment, I'm struggling to find a set of dimensions for mx5 front and rear uprights.
Dimensions for either mk1 or 2 would be very useful. Could anyone point me in the right direction please?
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Neville Jones
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| posted on 30/10/15 at 10:24 AM |
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quote:
Originally posted by Sam_68
Well, each to their own, and I freely admit that I'm nothing like as risk averse as some of these youngsters who won't go anywhere near a
'Seven' unless it's got a full cage with side intrusion bars...
...but on a 'Seven', you have a 1" steel tube, pretty much touching the side or your torso, that will deform and stay
deformed in the event of any significant side impact.
With a sandwich panel tub, you've potentially got a 9" wide triangular section torsion box, made of a material that doesn't
permanently deform, but does absorb an immense amount of energy as it progressively collapses (the honeycomb holds everything
together, so the carbon/grp skins disintegrate in a very linear, progressive manner in an impact... that's why they make crash boxes out of the
stuff for race and supercars).
Cages are mandatory on 7 type cars in most of the racing classes, and for very good reason. I've seen one go under armco....
Progressive Collapse, necessarily, means Permanent Deformation. Surely??
Sam, straight question, Have you ever built a composite chassis with your own hands? Yes or no?
Have you ever built a chassis using your recommended 'cut, rout, and fold' method. Yes or no??
You write as though you've read about these things in books, but haven't actually done it. Correct?
Russ has a lot of experience with these things, and I would think his advice and observations are well worth taking in.
Cheers,
Nev
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Sam_68
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| posted on 30/10/15 at 05:49 PM |
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Nev,
No, no and no, in the strictest terms.
But that is actually a misleading answer; I'm a designer.
I haven't yet built an entire chassis myself, personally, but I have worked with composites and sandwich panels with my own hands, including
rout-and-fold techniques and have been responsible for the design of full chassis.
I'm also an architect, but I've never laid a brick in my entire life...
I don't have a problem with Russ' perspective on safety, and I freely acknowledge that a small single-seater of whatever construction will
be vulnerable on the road.
Similarly. I'm aware of the racing regulations for various classes. As it happens, I've just signed a petition to the RAC objecting
against the changes to requirements for specialist sports cars ROPs.
If you don't want to drive a small single-seater, or an uncaged Seven, that's just fine, and entirely up to you - I'm not going to
force you to!
But, genuinely, in 30 years of driving Sevens and other lightweight kit and sports cars, I've never owned one with a cage, and
personally it doesn't bother me in the slightest. That's my choice too, presumably? 
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paddywil
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| posted on 31/10/15 at 03:47 PM |
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So I know this has been done to death elsewhere, but I want to know what's people's personal thoughts on spherical bearinnags vs nylon
bushings, in the context of suspension mounts?
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ceebmoj
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| posted on 31/10/15 at 06:09 PM |
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quote:
Originally posted by Sam_68
Lots of interesting stuff
I look forward to seeing your build, would you mind sharing some of the drawings? I ask because very time I start drawing something similar I get the
side bits done and struggle to work out what to do at the fount.
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