Morning all. JUst been looking up metal prices from an on-line place near me. Is 50mm x 5mm cds excessive for the de-dion tube? I only ask, since
it's half 
the price of 2" x 10 gauge. And if i get some. how hard wil this be to bend? Bearing in mind I only need a single small bend in
the middle, will bute froce and some heat do it?
Also, is 1" x 16 gauge enough for the front bones? Mine will be roughyl 2-3 " wider than book to meet my rear track.
[Edited on 9/3/06 by DIY Si]
I'd imagine you would have to be very strong to bend that evan with heat.
Could it be done with jacks of some sort then? Or am I just asking for trouble?
this might be of help :
from Yahoo article dated Mon May 21, 2001 7:22 pm
After pestering the poor fellow unmercifully, I just heard from Bill
Mulholland about the Caterham Dedion tube size. In the man's own words:
"The de-dion tubes O.D is 6.39 cm. The centre section does look reinforced
by the centre pickup for the caterham a-frame suspension - It's a triangular
box section welded on. I don't think it will be necessary for a locost
though - The loads of the two radius arms are in the ends off the tube."
So, smaller tube or don't bother with the reinforcements? I was hoping to use 50mm as it will fit much easier.
make a V-cut in the middle, ben it by hand (or just join the halves if you cut all the way through) and weld it back. The middle of the tube doesn't go through all the stress the ends suffer, so no problem here.
Ok, just so I get this straight in my head before I balls it all up. I don't need to worry about bending it since I can cut 'n' shut it. So the original idea of 50mm x 5mm will be ok as long as I can get full penetration on the welds? ie by using a deep V cut etc. Would this need bracing of some sort in the middle, since I'm planning on using a Watt's linkage as opposed to the Panhard rod?
If you are using a watts linkage then you can use the centre mounting as the reinforcement if you are clever.
That's what I was planning . Using a box type thing that overlaps both halves of the tube, but also mounts the linkage. Ok to use 3mm box/plate to make the box?
A Watts linkage will probably put less stress on the center of the tube than a panhard rod IMO.
50mm * 5mm is possibly a bit excessive though, very strong but it's going to be plenty heavy which kind of defeats the object a bit.
Have you started your de-dion tube yet?
If you need a part made I have access to laser cutting, metal punching tig,mig and tube bending, so can supply parts at a very reasonable price. If
your supply a drawing of what you want I will be happy to quote, or could supply prices for the rorty de-dion in kit form if you want.
If you want to see how I built mine you can look here:
http://www.newtier.com/graber/mid-engine/Images/Rear_Drive_Cradle/07-07-03/index.html
Not your standard Book setup.... 
Sgraber, that all looks quite nice, if poss a little on the large size?! But as you said with the pictures it won't be going anywhere!
jroberts, nope haven't started building it yet. Currently looking for parts/prices etc. How much would you want for a wider than normal rorty
kit? Needs to be the same track as the older granadas.
Will work out costs for you. U2U for more info.
50 x 5mm does sound a bit excessive.
You could try 2-1/2inch 14g or, if your car is lighter than usual, 2-1/2inch 16g or 2-1/4inch 14g.
If you must have a 50mm diameter then 3mm wall should be fine.
My DeDeon is 50mm x 3mm ERW and hasn't bent in 650miles. I live down bumpy country lanes too!
quote:
Originally posted by andyharding
My DeDeon is 50mm x 3mm ERW and hasn't bent in 650miles. I live down bumpy country lanes too!
So I couls safely use erw and save some money? Looking to do things on the very lo(w)cost where poss.