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I'm a bit worried
PaulBuz - 16/8/06 at 12:16 PM

My harness posts are made from 2mm walled RHS. A full nut is welded into the top.
Is this going to pass?
Its fully welded all around

PaulBuz - 16/8/06 at 12:17 PM

.

John Bonnett - 16/8/06 at 12:46 PM

I don't think the captive nut will be a problem but I would have a concern about the leverage, that in the event of a crash, would be applied to your fillet welds beacause of the length of the verticals. Normally harness mountings are on the transverse rail where there would just be a straight pull.

John

tom_loughlin - 16/8/06 at 01:13 PM

I cant really see a problem - my harness mounts are some inside treaded tube, welded to the chassis, but to bring the harnesses up to the correct height, I bought some long harness eyes (2" I think) and slided 1" tube over the eyelet, to raise the height to allow the harnesses to be in the correct position.

Your way of doing things looks a more sturdy way and more permanent than mine did, so I would imagine you'd be ok.

Tom

kb58 - 16/8/06 at 01:55 PM

quote:
Originally posted by John Bonnett
I don't think the captive nut will be a problem but I would have a concern about the leverage, that in the event of a crash, would be applied to your fillet welds beacause of the length of the verticals. Normally harness mountings are on the transverse rail where there would just be a straight pull.

John


What he said. To find if what you have is okay, hook a rope to an eye-bolt, then apply about 400lbs to mimic your weight in an accident.

I'm guessing the tube will rotate forward due to the torsion. In an accident this is Not what you want because it allows your body to get that much closer to the steering wheel.

02GF74 - 16/8/06 at 02:08 PM

I'd be inclined to put a fillet or traingluar box on top of the horizontal bar to the verical posts.

there will be some leverage and you are relying on those welds.

( the fact that your post is titled "I'm a bit worroed" shows you realise the problem)

[Edited on 16/8/06 by 02GF74]

JohnN - 16/8/06 at 03:08 PM

I agree with the too much leverage point of view.
The pillars will apply sufficient leverage to twist the horizontal bar and therefore not give the required restraint.

If the pillars were longer and extended down to the other lower member, and were similarly welded to that, then I would judge them more sturdy

[Edited on 16/8/06 by JohnN]

David Jenkins - 16/8/06 at 03:13 PM

As a minimum I'd be tempted to take the square tube down to the diagonals below, so that an impact won't just twist the top horizontal bar around.

I would also be tempted to (a) use thick-wall material, and (b) make a threaded insert for the top, rather than a welded-on nut.

Finally, whatever you make will be subject to the radius rules - watch that you don't leave sharp edges and corners anywhere.

Your basic idea is fine - the implementation "needs work".

David

Marcus - 16/8/06 at 03:52 PM

The basic idea has passed SVA many times, but I prefer welding bushes through a cross brace on the rollbar and triangulating the bar to the rear corners.

PaulBuz - 16/8/06 at 06:39 PM

Thanks for all the rplies- I think I will extend them down to the next rail