Roll bar prototype finish

 Apart from an old geezer getting a posh hat, this weekend has been very busy. I'll split it into several posts because otherwise I might miss something.

First task was the roll bar. With the hoop bolted in place, I ran a second tube down the side of the car to get an idea of how to brace it. I wanted to minimise bends on this part to make sure the loads went into the chassis and not into the bends. 

I've attached the brace as high as I could before the bend starts on the hoop. It then comes down to halfway down the top bar, then parallel to the same bar all the way down to the floor pan. 

This picture shows the final result once it had been glued and taped up;

A couple of things to note. The bar bends upwards and inwards, but I actually managed to do both in one bend. That does mean I can just have it bent in one (and I know the angle now), but I can't get them to cut either end. I'll have to order them longer and cut them to suit. 

The other thing is the forces involved. With the plastic bar I can see how it would deform, and as expected it's the side bar bend. However what I can do is add another bracket so it's not just fixed to the bottom. 

So now I can get this ordered. It'll be four pieces. The roll bar hoop, two sides and the centre bar. I still need to prototype that length but it's not going to be difficult. I then need to figure out how to get the body over the top of it, I might do that before I have the real thing. 

Looks like I'll need about 5 metres of tube, and 4 bends. 44.45mm tube for 5 metres is £66, I don't know how much the bending is though. Hopefully because they're only small bends in a single line it won't be too difficult to produce. It would probably cost more to post than to bend!

But that's it for the roll bar mock up, the next time I'll be working on it will be to weld it up. 

(Edit) A couple of extra photos;