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Bending flat steel bar
karlak - 10/4/10 at 05:56 PM

Further to my post on the broken Wing stay. I reckon the best way forward is to replace the broken (and other) top flat steel bars with a beefier type. May also help reduce the flappy wings i get at speed.

The current flat bar is 3mm x 20mm wide - I can probably go up to 30mm wide if needed and the depth is only limited, I guess by my abilty to bend the steel.

So, which type of steel would you recommend. I dont have any way of superheating the steel for bending, and only have a bench vice to use.

B&Q do Hot rolled steel flat bar is various dimensions. I have also read about Cold Finished steel.


Again any help, advice or experiences much appreciated


jacko - 10/4/10 at 06:03 PM

I used mild steel 25x5mm it has never snapped and it will bend in a vice


RichardK - 10/4/10 at 06:51 PM

I bent mine using 2 large sockets from my socket set held in the vice with the flat bar imbetween. Bent really nice with no heat, but bend only once.

Cheers

Rich


karlak - 10/4/10 at 06:57 PM

Thanks for the help.

Any idea where I may be able to get some mild steel ? One of the DIY stores tomorrow ??


David Jenkins - 10/4/10 at 06:59 PM

There is only one answer - stop it flapping in the first place.

Not everyone likes the alternative though...



zilspeed - 10/4/10 at 07:00 PM

Yes, you can get it from the DIY stores, at a premium.

Might I also suggest that insted of butt welding it to the end of the tube where it always breaks, you actually run it past the end of the tube and bolt it through.
It's a far more robust connection which will flex without issues.
The flexing of the welded joint is the true killer.


karlak - 10/4/10 at 07:18 PM

quote:
Originally posted by zilspeed
Yes, you can get it from the DIY stores, at a premium.

Might I also suggest that insted of butt welding it to the end of the tube where it always breaks, you actually run it past the end of the tube and bolt it through.
It's a far more robust connection which will flex without issues.
The flexing of the welded joint is the true killer.


Yep, I am going to copy what has already been done and that is Bolted. It has broken at the first bend which I reckon is partly due to the Steel only being 3mm.


Mal - 10/4/10 at 08:20 PM

Another vote for 5 x 25 strip. Also, it is thick enough to tap M6 for attaching the wings.
You need black mild steel rather than bright drawn, which is more prone to cracking when bent. It should not cost too much from a steel stockholder for a 3m length.
I cut a slot about 40mm long in the round section support tube for the strip to push into to give a longer weld than a butt joint.


Angel Acevedo - 12/4/10 at 06:11 AM

Try to make the angle between the stays as close to 90º as possible as at this angle one of the strips is resisting bending on the large side while the other is trying to flex, imagine a virtual Angle iron.