Aluminium monocoupes and kit cars

[mickrick]

Oooh! Thank You.
And what an interesting Man Friend Wood is!
http://home.clara.net/peterfrost/tryaneii.html
He even used a boatbuilding technique we call "Lofting".

Edited by mickrick on Sunday 7th November 09:21

[singlecoil]

I too was impressed by Friend Wood's car.



What I have in mind is rather different. I am thinking along the lines of a conventional 7 in size, shape and basic design. I foresee the monocoque forming the central section, with the front and rear suspension, rollover bar and seat belt upper mountings being carried on steel subframes that would be fixed to the front and rear bulkheads of the monocoque. I don't yet know the best way to carry out that attachment, and will be researching that.

My material of choice is birch plywood. Birch is a hardwood, and the plywood made from it is high-spec stuff, an 18mm sheet will typically be made of 15 laminations, which are WBP bonded (Water and Boil Proof). I foresee using this material (at various thicknesses) in combination with polyurethane foam- for instance, cockpit sides formed from an inner and outer skin of 6mm ply, to leave a 12mm gap, that gap to be filled with foamed-in-place 2-part PU foam.

Birch ply resists damp well, although its surface becomes very discoloured if left bare. I would be using an epoxy coating to prevent this, though.

This is not an one-off project, I would be hoping to sell the monocoques as part of a kit. I’m not really thinking about DIY construction of the monocoque itself.

Birch plywood can be machined to close tolerances. I could get the pieces cut by CNC router, more likely I would make templates for each section (or get those CNC cut) then cut out the pieces as I needed them and trim to exact size using a heavy duty router with a bearing guided cutter (a technique I have used a lot in the past).

One of the big attractions of this is that by making the monocoque is that I would be making much of the bodywork as well as the chassis, they are no longer two separate processes. I would also make the scuttle and the rear tub, possible the wing as well, out of plywood and they are all single plane curves. About the only non plywood parts that would be GRP nose cone, and an aluminium bonnet

[mickrick]

You may be interested in this
http://nida-core.com/english/
and this
http://www.plascore.com/
for alternatives to cores.

[Ferg]

Much as I'd love to see a wooden monocoque succeed, I can't help but think that surely GRP IS the best bet. Isn't it? I suppose it's downfall MIGHT be the expense of a mould...

[singlecoil]

mickrick said:

You may be interested in this
http://nida-core.com/english/
and this
http://www.plascore.com/
for alternatives to cores.

Thanks for those, but the problem with them is that they need to be bonded to the structure, whereas with the PU foam, foamed in situ, I get core and bonding at the same time!

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

[Ferg]

singlecoil said:

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

Well I'm just going on my own experience. My GRP monocoque is self coloured, contains complex curves, is relatively light (?), is relatively cheap in materials (Gelcoated GRP only), requires no subframes... it's ease of repair is maybe questionable, but then a wooden one would be too, wouldn't it?

Perhaps as a one-off it's uneconomical...

[mickrick]

You can buy the cores already laminated, in a variety of materials.
So you could cut panels and slot them together. Only need to bond the joints then.
See here
http://nida-core.com/english/nidaprod_lamin_veneer...

The jeweled Aluminium is my favorite.
Here
http://nida-core.com/english/nidaprod_lamin_metals...

Edited by mickrick on Sunday 7th November 10:52

[singlecoil]

Ferg said:

singlecoil said:

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

Well I'm just going on my own experience. My GRP monocoque is self coloured, contains complex curves, is relatively light (?), is relatively cheap in materials (Gelcoated GRP only), requires no subframes... it's ease of repair is maybe questionable, but then a wooden one would be too, wouldn't it?

Perhaps as a one-off it's uneconomical...

There's no doubt that if one wanted to create a Libra-shaped car then a GRP composite moncoque would be by far the best way to go about it. I'm not in that position, though. It's evident from studying the market that the 7 type car is by far the most popular. I prefer mid-engined coupes myself, but that market is difficult to enter, and to make a success of, and as I want to find a project that I can get on with, and as my financial resources are limited, I've decided to go the 7 route.

mickrick said:

You can buy the cores already laminated, in a variety of materials.
So you could cut panels and slot them together. Only need to bond the joints then.
See here
http://nida-core.com/english/nidaprod_lamin_veneer...

The jeweled Aluminium is my favorite.
Here
http://nida-core.com/english/nidaprod_lamin_metals...

Thanks for those links, interesting stuff. Two things that worry me about that type of material is that the resistance to penetration is poor, and it would not be anything like so easy to bolt things to it.

How does the cost compare, have you looked into that?

[Ferg]

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

Well I'm just going on my own experience. My GRP monocoque is self coloured, contains complex curves, is relatively light (?), is relatively cheap in materials (Gelcoated GRP only), requires no subframes... it's ease of repair is maybe questionable, but then a wooden one would be too, wouldn't it?

Perhaps as a one-off it's uneconomical...

There's no doubt that if one wanted to create a Libra-shaped car then a GRP composite moncoque would be by far the best way to go about it.

Gotcha!!

[singlecoil]

Ferg said:

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

Well I'm just going on my own experience. My GRP monocoque is self coloured, contains complex curves, is relatively light (?), is relatively cheap in materials (Gelcoated GRP only), requires no subframes... it's ease of repair is maybe questionable, but then a wooden one would be too, wouldn't it?

Perhaps as a one-off it's uneconomical...

There's no doubt that if one wanted to create a Libra-shaped car then a GRP composite moncoque would be by far the best way to go about it.

Gotcha!!

Eh? Sorry, I don't consider myself got. I don't want to create a Libra-shaped car.

Neither do Potenza, apparently

[Sam_68]

singlecoil said:

I don't want to create a Libra-shaped car.

Curves add stiffness. You'll notice that all Costin's designs used quite large torsion boxes. There's a reason for that.

I've played around with the idea of plywood (which I admit would be very attractive, if you could make it work) and even seriously considered it for my own single seater project, but ultimately ruled it out because even if you form nice, stiff torsion boxes with curved outer faces, like Costin and Friend Wood, it simply wasn't adding up to have anywhere near the stiffness:weight I thought necessary.

[Ferg]

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

Well I'm just going on my own experience. My GRP monocoque is self coloured, contains complex curves, is relatively light (?), is relatively cheap in materials (Gelcoated GRP only), requires no subframes... it's ease of repair is maybe questionable, but then a wooden one would be too, wouldn't it?

Perhaps as a one-off it's uneconomical...

There's no doubt that if one wanted to create a Libra-shaped car then a GRP composite moncoque would be by far the best way to go about it.

Gotcha!!

Eh? Sorry, I don't consider myself got. I don't want to create a Libra-shaped car.

Neither do Potenza, apparently

LOL!!
I mean "I've got the point you are making."

You can be so paranoid!!

[mickrick]

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

Well I'm just going on my own experience. My GRP monocoque is self coloured, contains complex curves, is relatively light (?), is relatively cheap in materials (Gelcoated GRP only), requires no subframes... it's ease of repair is maybe questionable, but then a wooden one would be too, wouldn't it?

Perhaps as a one-off it's uneconomical...

There's no doubt that if one wanted to create a Libra-shaped car then a GRP composite moncoque would be by far the best way to go about it. I'm not in that position, though. It's evident from studying the market that the 7 type car is by far the most popular. I prefer mid-engined coupes myself, but that market is difficult to enter, and to make a success of, and as I want to find a project that I can get on with, and as my financial resources are limited, I've decided to go the 7 route.

mickrick said:

You can buy the cores already laminated, in a variety of materials.
So you could cut panels and slot them together. Only need to bond the joints then.
See here
http://nida-core.com/english/nidaprod_lamin_veneer...

The jeweled Aluminium is my favorite.
Here
http://nida-core.com/english/nidaprod_lamin_metals...

Thanks for those links, interesting stuff. Two things that worry me about that type of material is that the resistance to penetration is poor, and it would not be anything like so easy to bolt things to it.

How does the cost compare, have you looked into that?

No I haven't looked at cost, as I'm not looking at building a one off myself. I already have too many projects on the go.
As for penetration, are you refering to say, a side impact?
A caterham has an aluminium honeycombe side panel in the cockpit.
Get sidswiped in one, and it won't do you any good anyway.
You'd be surprised how tough the stuff is, after all, they build boats out of the stuff.
To bolt stuff to it, you could inject an epoxy plug.
I did a weekend at Wessex Resins, the makers of West System epoxies, and we drilled a core out of a large block of hardwood.
Coated the thread of an eye bolt with releas wax, and set it in the core filled with high density filler/resin mix.
When it was set, we put it in a tensile test machine. It ripped the block of wood apart before the eye bolt pulled out! After we could unscrew the bolt, leaving the thread intact.

[singlecoil]

Ferg said:

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

Well I'm just going on my own experience. My GRP monocoque is self coloured, contains complex curves, is relatively light (?), is relatively cheap in materials (Gelcoated GRP only), requires no subframes... it's ease of repair is maybe questionable, but then a wooden one would be too, wouldn't it?

Perhaps as a one-off it's uneconomical...

There's no doubt that if one wanted to create a Libra-shaped car then a GRP composite moncoque would be by far the best way to go about it.

Gotcha!!

Eh? Sorry, I don't consider myself got. I don't want to create a Libra-shaped car.

Neither do Potenza, apparently

LOL!!
I mean "I've got the point you are making."

You can be so paranoid!!

I'm afraid I am finding the points you are making just a little bit too obscure.

[Ferg]

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

singlecoil said:

Ferg said:

I can't help but think that surely GRP IS the best bet. Isn't it?

The thing is, why do you think that? Feel free to point out problems, or even talk me out of it completely, but I will need some reasons.

Well I'm just going on my own experience. My GRP monocoque is self coloured, contains complex curves, is relatively light (?), is relatively cheap in materials (Gelcoated GRP only), requires no subframes... it's ease of repair is maybe questionable, but then a wooden one would be too, wouldn't it?

Perhaps as a one-off it's uneconomical...

There's no doubt that if one wanted to create a Libra-shaped car then a GRP composite moncoque would be by far the best way to go about it.

Gotcha!!

Eh? Sorry, I don't consider myself got. I don't want to create a Libra-shaped car.

Neither do Potenza, apparently

LOL!!
I mean "I've got the point you are making."

You can be so paranoid!!

I'm afraid I am finding the points you are making just a little bit too obscure.

Right. Now I AM confused!

[singlecoil]

Sam_68 said:

singlecoil said:

I don't want to create a Libra-shaped car.

Curves add stiffness. You'll notice that all Costin's designs used quite large torsion boxes. There's a reason for that.

I knew that too. Sorry if I'm coming across a bit thick, and needing to be told fairly basic stuff like that.

Sam_68 said:

I've played around with the idea of plywood (which I admit would be very attractive, if you could make it work) and even seriously considered it for my own single seater project, but ultimately ruled it out because even if you form nice, stiff torsion boxes with curved outer faces, like Costin and Friend Wood, it simply wasn't adding up to have anywhere near the stiffness:weight I thought necessary.

Do you have any sources I can get some figures from, the little experiments I've been able to do in the workshop have been quite promising.

[singlecoil]

Ferg said:

Right. Now I AM confused!

Sorry about that, as I understand it, you are saying that GRP would be better for my project than plywood, and you cite the Libra as an example, but when I agree that GRP is best for Libra type cars, you say Gotcha, but I'm not trying to make a Libra type car, so do you now see why I'm not quite seeing what you are getting at?

[Ferg]

singlecoil said:

Ferg said:

Right. Now I AM confused!

Sorry about that, as I understand it, you are saying that GRP would be better for my project than plywood, and you cite the Libra as an example, but when I agree that GRP is best for Libra type cars, you say Gotcha, but I'm not trying to make a Libra type car, so do you now see why I'm not quite seeing what you are getting at?

Right.

Yes, I said that.
Yes, you said you weren't making a Libra shaped car.
Yes, I said 'Gotcha', but what I MEANT by that was " Oh, I understand now, thanks for explaining" OR "Ah, I've got what you mean" OR "Got ya" OR "Gotcha"

That's all. You misunderstood me. No problem. That's the downside of the 'Net, eh??! Now my tiny brain has understood, I see what you mean about a Seven shaped car with a wooden mono.

As an aside, I built a Burlington Arrow back in the '80s. That had a Herald chassis with bulkhead frames of 1" box steel all joined together with 1" blockboard down the sides.

[singlecoil]

Ferg said:

'Gotcha',

Misunderstanding cleared up, I'm glad to say. This is what I was thinking of

http://en.wikipedia.org/wiki/Noel%27s_House_Party

"Gotcha

Originally called the "Gotcha Oscars" until the threat of legal action from the Academy of Motion Picture Arts and Sciences (which also prompted a redesign of the award)[citation needed], hidden camera practical jokes were played on celebrities. Notable victims were Barbara Windsor, Carol Vorderman, Jill Dando, Dave Lee Travis, Richard Whiteley, Eddie Large, Samantha Janus, Yvette Fielding and the Queens Park Rangers football club, although in the final series Dale Winton turned the tables on Edmonds with a surprise challenge which ended with a gunging. Another notable victim was Annabel Giles as she was the 1st victim who managed to spot the hidden camera whilst sitting in the back of a car and therefore the prank backfired. But Noel had the last laugh as in revenge, he had her gunged."

[Dr Derek Doctors]

Also not se if its been mentioned yet but just about the greatest Sports Prototype/GT Car of all time the Porsche 962 used an Ally monocoque