jestre
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| posted on 2/2/05 at 03:15 PM |
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Steel on bottom of chassis
Can 18 guage be used or is it to thin?
The book says they used the roof of the escort, I can't believe that was the 16 guage (1/8" the book calls for.
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MikeRJ
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| posted on 2/2/05 at 03:34 PM |
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quote:
Originally posted by jestre
Can 18 guage be used or is it to thin?
The book says they used the roof of the escort, I can't believe that was the 16 guage (1/8" the book calls for.
16 gauge is 1/16". I guess 18 guage would be ok as long as it was supported well, but 16 would give more protection from piercing.
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ko_racer
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| posted on 2/2/05 at 03:43 PM |
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I only used 18swg for the floor (as per the book for a race chassis)
It is plenty strong enough, and a good deal lighter than a 16swg floor.
If you are building it to the book spec the largest unsupported area will only be around 40cm x 80cm
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James
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| posted on 2/2/05 at 04:18 PM |
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Doesn't need to be anywhere near as thick as 16gauge. Which'll weight a ton.
Mine's about 1mm (possibly thinner- can't remember now) and I ran a pair of swage lines down each half of the floor which help stop it
popping when you get in and make it loads stiffer.
I'll shortly drill a couple of holes in the swage grooves so that water in the cockpit can run out once it's collected in the swages.
Hope that makes sense.
Cheers,
James
[Edited on 2/2/05 by James]
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kb58
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| posted on 2/2/05 at 04:30 PM |
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My floor is 0.035-0.040 stainless, which I'd think would be very desirable in wet areas. Besides, even if you paint an ordinary steel floor,
it'll quickly be blasted off by rocks and sand.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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jestre
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| posted on 2/2/05 at 05:25 PM |
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OK.. sounds good. I found a typo in the book.
its describes 16 guage as 1/8th inch.
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Mark Allanson
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| posted on 2/2/05 at 06:39 PM |
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Out of interest, a Mk2 escort roof is 20g
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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kb58
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| posted on 2/2/05 at 07:49 PM |
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quote:
Originally posted by Dave Ashurst
quote:
....even if you paint an ordinary steel floor, it'll quickly be blasted off by rocks and sand.
 What are your roads like, kb58?!!
Just regular roads, but over time the sand, pebbles, and gravel will eventually remove whatever paint is on the bottom of the car. I only suggested
the stainless so it's one less thing to worry about, and it doesn't have to be painted.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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DavidM
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| posted on 2/2/05 at 09:40 PM |
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I used 18swg (1.2mm). Still bloody heavy. I'll be using Aluminium on my next one.
Assuming I ever finish this one.
David
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JoelP
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| posted on 2/2/05 at 09:46 PM |
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never mind the floor, i'll be doing my next one fred flintstone style...  or clingfilm.
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jestre
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| posted on 3/2/05 at 12:02 AM |
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Has anyone used aluminum? if so how thick and how much $?
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kaymar
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| posted on 3/2/05 at 10:26 PM |
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I believe dax use aluminium for the floor also on the one i have looked at the transmision tunnel appears to be far less engineered/ dare i say
weaker. in fact reallt was not much there at all.
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flak monkey
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| posted on 3/2/05 at 10:28 PM |
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A lot of manufacturers are using ali floors. Usually about 2mm thick (still a considerable weight saving over 1.6mm steel) attached with a combination
of PU adhesive and structural rivets. Little/no loss of rigidity.
Cheers,
David
Sera
http://www.motosera.com
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MikeR
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| posted on 4/2/05 at 06:41 PM |
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i did a lot of calculation and after hearing a lot of builders had used 2.5mm ali decided on 1.2mm steel. I could weld it securely to the car, weight
around the same, better resistance to puncture than ali......
(also easier to attach)
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britishtrident
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| posted on 4/2/05 at 07:53 PM |
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quote:
Originally posted by kaymar
I believe dax use aluminium for the floor also on the one i have looked at the transmision tunnel appears to be far less engineered/ dare i say
weaker. in fact reallt was not much there at all.
Ever seen the tunnel in a real Lotus Seven or early Catering van ? ;-) ;-) ;-)
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cymtriks
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| posted on 6/2/05 at 02:18 PM |
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Aluminium floors can be made to work well and the floor has very little influence on overall chassis stiffness. However there have been cases of
aluminium floors falling out so be warned. This is largely due to inappropriate rivets (big head ones are available and are better), inadequate number
of rivets, or a poor chassis stiffness which allows flex to gradually work the rivets loose. Caterham have a very stiff chassis which helps keep their
floor on.
For a home build I'd suggest 18g steel. This is a lot lighter than 16g and is still OKish when you step on it to get in and out. Adding swage
lines, as suggested earlier in this thread is a good fix if you find that OKish isn't good enough. 20g could be used but I'd have thought
it would be too tricky to weld on properly as thin sheet can be tempermental when welded. This will flex a bit when you step on it but swag lines, as
above, or an extra tube, as in my high stiffness mods, would fix this.
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imull
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| posted on 6/2/05 at 05:17 PM |
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if you plan on using aluminium, spend a little extra and get duralumin sheet. A lot tougher thna alumium and only slightly heavier.
Its also used for sumpguards on 90% of rally cars which should demonstate its durability levels....
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NS Dev
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| posted on 7/2/05 at 11:15 PM |
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I have the std Stuart Taylor "race" alloy floor, which is pretty thin ally (18 swg I guess) and is the same as two westfields that I have
been in. It's a bit flexible when you stand on it in the middle of the floor but there are 350 or so rivets and PU adhesive holding onto it, and
I will put in some reinforcement under the seat area.
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MikeR
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| posted on 8/2/05 at 01:11 PM |
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just to be pedantic.........
has anyone weighed how much a ali floor + rivets + adhesive + seat strengthening is compared to a steel floor + weld?
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flak monkey
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| posted on 8/2/05 at 01:20 PM |
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1.2mm steel floor alone weighs 12.5Kg. So say around 13Kg all welded in.
2mm ali floor weighs 6.5Kg. Remember for every rivet you remove some of the loor too.... Probably 7Kg riveted. Probably about a tube of PU
adhesive...about 0.5Kg?. Seat strengthening depends on whether you put 2 steel strips in, or plates. Say strips, probably about another 2.5Kg. So in
total 10Kg maybe.
Saving a whopping 3Kg  . Of course the weights for the adhesive and steel are guesses...
David
Sera
http://www.motosera.com
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MikeR
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| posted on 8/2/05 at 03:26 PM |
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aaah, but that value will change when the ali starts to react with the steel!
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flak monkey
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| posted on 8/2/05 at 03:35 PM |
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Galvanic corrosion...The ali will only react with the steel if it is in contact with it, and the contact gets damp. By using PU adhesive the ali is
not actually in contact with the chassis..in theory. Also most people would paint their chassis before riveting the floor on...
David
Sera
http://www.motosera.com
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NigeEss
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| posted on 9/2/05 at 07:38 PM |
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Is it wise to paint the floor before bonding with PU ?
After all, the bond will only be as strong as the substrate it's fixed to..
Time is an illusion. Lunchtime doubly so.................Douglas Adams.
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