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steel sides and floor
locost_bryan - 21/4/05 at 04:41 AM

Would welded steel side panels make the chassis stiffer?

I am planning to weld on a steel floor (and trans tunnel as per Cymtrik's mods), and wondered if doing the same to the sides would add more strength and torsional rigidity? What about for the rear bulkhead and/or footwells?

Don't think it would add too much weight...

longwayoff - 21/4/05 at 05:10 AM

I bet it would add a lot of weight and isn’t it stiff enough already?

smart51 - 21/4/05 at 07:03 AM

it may improve stiffness slightly but as the forces on the sheet metal are along the sheet (rather than a bending motion) then the sheer size of the area of metal means that Aluminium is likely to be more than good enough.

Steel is 3 times heavier than Aluminium for the same thickness and so you are likely to lose out more in terms of weight than you will gain in rigidity.

Also, steel rusts.

ned - 21/4/05 at 09:12 AM

quote:
Originally posted by smart51
Also, steel rusts.

unless you do as some have and use a very thin (0.9mm irrc) stainless steel, this is how the isonblade was done iirc.

Ned.

Ian Pearson - 21/4/05 at 09:24 AM

Depends on whether you are building a Formula 1 beater or not. I'm not planning to race or compete in any way with my car. I used steel for the floor and for the tuneel and footwells. I used ali for the rear bulkhead, and for all the body panels.

smart51 - 21/4/05 at 10:14 AM

can you weld stainless sheet to mild tube?
if you rivet and bond it, will you get any increase in stiffness?

clbarclay - 21/4/05 at 11:25 AM

A general rule of thumb for rivents (the one i was told at least) is they need a gap of 1.5 x the rivent diameter between each rivet. Any less and the metal is too weak, bigger gap equals less rivets (so intheory less strengh).

That means a 4mm rivet every 14mm (distance between rivet centers)

Or 3mm rivet every 7.5mm.


If you did that then just think how many rivets there could be on a locost.

omega 24 v6 - 21/4/05 at 11:42 AM

With the right wire and gas i'm sure you can weld stainless to mild. Could ask at work if you want.

kb58 - 21/4/05 at 02:11 PM

quote:
Originally posted by clbarclay
A general rule of thumb for rivents (the one i was told at least) is they need a gap of 1.5 x the rivent diameter between each rivet.


Are you sure? I heard the same rule but for something completely different, that the rivet hole should be greater then 1.5 diameters away from an edge.

As far as spacing, it's much more, like typically 1-3" between rivets.

And yes you can weld stainless to mild steel no problem. You just need to use stainless wire of a greater number then the stainless that's being welded.

[Edited on 4/21/05 by kb58]

907 - 21/4/05 at 03:30 PM

Stainless to Mild Steel ?

Use 309 wire/filler rod.

I do warn you though, because of it's high
chrome/nickel content, it's not locost.

HTH

Paul G

clbarclay - 21/4/05 at 05:51 PM

quote:
Originally posted by kb58
quote:
Originally posted by clbarclay
A general rule of thumb for rivents (the one i was told at least) is they need a gap of 1.5 x the rivent diameter between each rivet.


Are you sure? I heard the same rule but for something completely different, that the rivet hole should be greater then 1.5 diameters away from an edge.

As far as spacing, it's much more, like typically 1-3" between rivets.

And yes you can weld stainless to mild steel no problem. You just need to use stainless wire of a greater number then the stainless that's being welded.

[Edited on 4/21/05 by kb58]


Thats what I was told regards the maximum number of rivets you can use in a straight line. Thats not to say its correct.

The same ratio might be used in many general egineering rules. Its a bit like the irational number 'e' that keeps croping up in nature.

Liam - 21/4/05 at 06:39 PM

Yeah I think that's for distance to edges. Seems a bit close for rivet spacing.

In aviation (well on our airship at least) the rule is you must have at least 2D (where D is the diameter of the hole) from the edge of a sheet to a hole. This applies to any hole - not just rivet holes. As for spacing it depends on the loading of the part, but i can't recall seeing any closer spacing than about an inch.

Liam

[Edited on 21/4/05 by Liam]