Tank platform and roll bar brace

 This weekend was another busy one, bringing out the rear of the diff cage to provide a good platform for the fuel tank and somewhere fort he rear braces to go. 

The first thing that had to change was the position of the roll bar support. I had originally planned it for right on the corner of the fuel tank like this;

But in real life that wasn't going to be possible. The platform for the roll bar would be sticking out into thin air and very difficult to support. Instead I went for bringing in the support to line up with the tank;

Using 1 inch steel in a U shape off the back of the diff cage means that both the fuel tank and the roll cage support get some pretty beefy metal. I reproduced the roll hoop base to make sure it's consistent, so it's a 110mm pad with 70mm bolt distances. The whole thing will be braced to the bottom of the diff cage, and I also cut some more 3mm plate to form a box. That might seem a bit 'excessive' but does that word have meaning when it comes to roll cage strength?

The only doubt now is that the angle of the bar is lower than MSUK yearbook requirements. It's sat at 25 degrees instead of the required 30. To get the 30 degrees I'd have to move it back 50mm. That might be possible if I can get the captive bolts in place inside the rear tube (which isn't a bad thing, I just need to cut open the tube in order to weld them in place).

[Maths reference, with a 734mm long bar, 20 degrees needs 251mm from base to base, 25 degrees is 310mm and 30 degrees is 367mm]. 

In fact, just thinking about that step... I could take the plates back off, weld the nuts to the bottom of the plate (the same as it's done for the normal suspension top), then just cut an appropriate hole in the bar. That would mean the nut is in place but the bar itself doesn't have a big gaping hole in it. Thankfully I've only tacked the plated in place at this stage, it won't take much to cut the tacks and start again. I just need to drill the holes first to make sure it lines back up when I'm done. That's this evenings job I think. 

For tube lengths, I've got each strut at 800, the cross bar at 1000, then whatever is needed for the hoop. 

In other news, I got the captive nuts welded in for the seat bases, and the matching holes drilled in the wood. It looks like the bolts screw through far enough to come up flush with the wood, so that should mean I won't feel the bolts through the seat. I'm still worried about the movement on the drivers seat though, it seems to bind very easily. Still, given that it won't be moving very often I am hoping it's ok as is.