25x25x2mm













Easy !

Modesto

Is there a good reason why I couldn't do something similar with the upper round section tube? - I think I could make it much neater than with my useless bending. If the roll bar supports go to the lower rear corners instead of the upper bar there wouldn't be any chassis strength issues to worry about would there?
Cheers
Dave

I did something similar to get the bend in one of my exhaust tubes.

Except I did about 30 cuts and to keep them narrow enough... by hacksaw!

Cheers,
James

The only problem I can see with doing it this way is getting the panel neat on the square section - without any experience I would imagine it would be much harder to make it look neat on square section than round (assuming you are using ali rather than grp).

There's no problem strength wise doing it, as Indy's don't even have a top tube at all! As said, it may cause a slight issue getting the bottom of the back panel to sit right, but only if you're using ally.

I used that method for "bending" my dash tube. What happens is the shrinkage from the multiple welds can result in a very differnent shape than what you started with!

You left out the most important step... welding it. When you weld it, that 90 degree shape will absolutely change, even if you alternate sides.

It can work, but don't expect it to stay at its initial angle! After welding all the cuts, you'll have to add another cut to put the angle back where it started.

You should have no movement or distortion if you spot-tack all cuts first and as you bead weld skip around (top, back, one end then the other etc.) never letting any one area get too hot. Short beads and move around the entire part.

On a small piece you may also want to clamp it to another straight channel until you get the spot tacks in place. It is important to weld straight on through the tacks as if they don't exist.

Dick Bear

If you make a template/former for the outside of the curve (3/4 MDF or ply) and clamp from top to bottom, you could then spot the joins on the inside of the curve, adjust where necessary, spot the top, adjust again before it is too rigid. You should be able to minimise the distortion and keep your finished curves the same. Be careful when you attach you panels to these curves because if there are large gaps between the back of the panel and box section it will create stress raising areas and my eventually crack the panel or pop your rivets.

regards

Steve

I'll take pictures of the hole process in the last corner.

Modesto

OK, I'm inspired!
This is my next job on the car so here goes...
Cheers
Dave

Here you are :
















































cheers,

Modesto

This has been mentioned before but just to repeat, square tube (as well as round tube) can be bent very nicely cold using a bending beam.

Sorry forgot the pic