Monday 22 May 2023

Roll bar hoop installed

 This weekend was very productive, I managed to end up with a really painful ankle after a piece of wood jumped out and bit me, and half a pinkie fingernail missing when a piece of metal that I was drilling decided to grab and spin... Anyway, on to the real purpose of the weekend.

The first job was to cut some mounting plate from 3mm plate, then drill the holes for the bolts. That was pretty simple, and meant I had a platform for the roll bar;



Supporting the hoop from above I could see roughly where it would sit, but I could also see that it wasn't even. Not overly surprising to be honest, I specifically asked for the material to be cut at a right angle. It's clear from the pictures above that there was too much of a gap, and it was quite clear that one leg was longer than the other. 

Once I'd figured out how to measure the tube, I was able to cut and profile the ends. Oh, cutting roll bar tube with a hacksaw is an exercise in futility! The angry grinder and cutting disc came to the rescue, although I was still giving myself about 20mm of grinding and profiling to do. 

Eventually I got it level and flat across the surfaces, so I mounted it back on to the car. At this point it occurred to be that I can gain myself a few centimetres in order to increase the angle between the hoop and the brace. I therefore moved the roll bar forward on the plate until it was inline with the bolts. A quick tack and weld up, and this is what I have now;


The tube still sits within the four bolt pattern, but it's closer to the chassis frame which hopefully is a good thing? I can do the same with the rear braces, move those backwards. Every couple of inches gets me another five degrees, so with this being one inch forward I'm halfway there. Obviously I'll never go racing in this (maybe a track day at most), but at least if I aim for what MSUK suggest then I can have a bit of peace of mind. 

One thing I did note that despite me getting everything really hot when welding, the bolts loosened off really easily. There was no misalignment or similar issues. I thought I had twisted something when I started tacking it up as the right hand side had deflected a few mm. but after bracing it, welding it up then letting it cool it all settled down into a good position. 

For the rear braces it's back to the frame;


This was a little easier, with the frame not yet on the car I was able to cut and drill the plates for the braces without having to contort myself across the back of the car. Once this is welded up and on the back of the car I can finish the roll bar. Oh, I did notice that the passenger side plate doesn't quite line up anymore due to the captive nut weld, I'll have to bear that in mind when I finish the welding (they're only tacked in place at the moment). 

However there is a sequence to follow now. I want to get to the back of the car, which does mean that turning the car round in the garage would be the best option. But the bodywork supports can also benefit from the car being the other way round. So next job is to tack on the side support that is visible, then spin the car, then do the other side support and the rear. That way I can have the roll bar done and the bodywork support ready to go at a similar time. I still need to understand how the braces go through the bodywork, especially with the saddle clamps that I'll be using.

Oh, on the subject of saddle clamps...  I can see how they would fit and I think they'll only need a small amount of trimming to get the angle. It's going to be how close I can get the braces to vertical that'll be the tricky issue. Too far along and the angle will be off, but too close to the bend and it'll be the bend itself that causes the saddle clamps to need adjustment. And I've just thought of something, I need to find the centre line of the roll bar. Logic would suggest that it's the centre line of the car, but even that isn't straightforward. I might get the centreline sorted tonight as a mini-project, I won't have enough time to get all the welding done and turn the car around. Tomorrow I'm in the office and Wednesday will be making planters for the front garden. 

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