Rescued attachment YBrace.JPG
I have been coming along well with my chassis. I have not yet got any round tube for the triangulation pieces of TR6 TR4 and TR2.
I do however have some square box section left over from the tunnel section. (Doh... ordered 2 x 6m lengths)
My quesion is this. Could I safely use this 3/4 x 3/4 box section instead of round? Does the round have some magical proporties? Just seems a shame
to go buying more steel and storing a load that I haven't used.
Vince,
I'm going to use square tube, and have seen other chassis with square tube here too.
I might use 1" as opposed to 3/4", anyone know if these tubes are mainly in compression or tension?
Cheers,
Ned.
if you look at cimtrix's post re stiifnes he recommends that they should be upped to 1" either sq or round
see here
http://forum.locostbuilders.co.uk/xmb/viewthread.php?tid=5810
[Edited on 3/9/03 by timf]
quote:
Originally posted by VinceGledhill
I have been coming along well with my chassis. I have not yet got any round tube for the triangulation pieces of TR6 TR4 and TR2.
I do however have some square box section left over from the tunnel section. (Doh... ordered 2 x 6m lengths)
My quesion is this. Could I safely use this 3/4 x 3/4 box section instead of round? Does the round have some magical proporties? Just seems a shame to go buying more steel and storing a load that I haven't used.
Thanks for that guys. I've got some 1 inch tube left. (only a Z tube to do) so probably will have enough to finish it off.
Nothing magical about round then?
Nothing special, other than it might be easier to weld because of the tight angles...
I used 1 inch sqare, and on my car, made an 'X' brace instead of just one diagonal.
However, be careful if you try this cos on my car one of them projects outside the flat panel that would form the side. Im talking of the engine bay
section. Not a problem on my car, I just slightly angled the panels. This wont be seen as a morgan look alike has body panels over the innner ones
(wings and running boards) anyway.
Just be sure that the tube doesnt extend outside of the 'flat' area, unless you want a curved look.
atb
steve
[Edited on 3/9/03 by stephen_gusterson]
surely round is less likely to crush? ie go flat and fold?
i'd *guess* the round tube may be better in tension, but in compression a larger diameter/section of tube should be stronger.
I'm sure someone will correct me...
all IMHO
Ned.
I'll do the TR1 and 2 in 1" square. And the others in 3/4 inch square. May add a diagonal to the passenger foot well too.
All the TR tubes are a bit small for their job. This is especially true for TR1 and TR2 which are realy only suitable for smaller engines and lighter
cars.
A proper finite element analysis of the lowcost chassis shows that the most highly loaded tubes are those that connect the front and back of the
engine bay. Of these tubes TR1 & 2 are the longest, the thinest and carry a high load.
I'd suggest 16g 1 inch square or 14g 1 inch round.
Take a look at my chassis design in the photos section. The double Y brace across the engine bay is very effective and much better than any other way
of getting the tubes around a wide engine. The chassis design shown is over twice the book chassis stiffness, about the same as a Caterham chassis and
not far behind an ultima chassis in stiffness terms. You'll need to scroll back through my earlier posts to get all the details of the
modifications.
Hope I'm not too late to help!
Thanks for the advice cymtriks. I've done one side of the engine bay which is in 16g 1 inch square. The other side is yet to cut.
The Y section engine bay modification looks great. I'll certainly add that because I've not done the "R" tube yet anyway.
Ref the Y tube, I'll form a 90 degree bend with two 45's intersecting at the centre of the Y. Therefore the two top parts of the Y as you
look at it will be the same length. The lower part of the Y cut and made to fit.
If this is not suitable then please let me know. Otherwise I will just get on with the job this afternoon.
Variation on a theme
Rescued attachment YBrace.JPG