Thursday, 30 November 2017

Stand And Deliver

To say the last few months have has been a bit of a rollercoaster would be masterpiece of understatement.

Unfortunately Mikey (my brother and partner on this project) and I lost our mum a month or so ago after a very short sickness with brain cancer. As soon as we knew it was it worst-case-scenario the whole project went on stop and nobody has really looked at the car until last week.

However, the other, much happier reason for no car-action is little Isaac arrived about three weeks ago. My bro's first kid and definitely something to smile about after such a tough few months for everyone. It's a real shame our mum couldn't hang in there long enough to meet him but he did arrive Just in time to see Elfyn win the Wales rally GB. That has to be a good omen for the little guy.

Speaking of the WRGB, I put 20 quid on Elfyn for the outright win on the Thursday before the event which netted a tidy £160 for the Motorsport coffers. My dad has donated some of his premium bond cash and we sold a few bits like the wheels my bro polished up so we now have about fifteen hundred quid to keep us going for the time being.


Right,

In my last post the car was still parked up at my Dad's place in north wales after coming back from Harry Hockley to get the cage measured up. It's now back down at my place in Cornwall. I've finally got around to painting the garage floor and hanging all the spanners up, so the garage is looking a bit more organised than it was and we can now crack on in earnest with all the seam welding and getting the cage installed properly.

A quick scan of the internet will tell you that before seam welding any car chassis it is prudent to make sure it's straight by setting it in a jig or at the very least setting it out on level stands. It will be so stiff once the seam welding and cage install are completed any deviation from true will be welded into it for life.

With this in mind I set about making some adjustable axle stand by augmenting all the old Halfords ones I had lying around. This is what I came up with


Pretty simple really, I cut a small section of steel tube (I'm not to sure on OD off the top of my head but as luck would have it it was perfect fit inside the tubular part of the stand) and welded a M20 nut and washer to the end of it, tapped it into the axle stand until it was proud by about 5-8mm then welded it in place around the top of the stand. I then cut a 400mm section of M20 bar and welded another nut and washer together. Threaded the bar into the stand and then threaded the second nut down to the top of the tube (barely finger tight) and welded it in place.

after that I removed the M20 bar and set another nut to precisely 60mm from the top of the thread using a combi-square and welded it in place before threading on one more nut to act as a lock-nut.

Now, assuming the chassis was twisted (were only really looking for torsional distortion here) it would would fail to rest on the stands on opposite front and rear corners and rock across the other two. So the stands would need to be fixed to the floor so the shell could then be pulled down onto the ones it was failing to meet with turn-buckles. That's what the length of box section across the bottom is for, It allows a little bit of lateral wiggle room to line the stand up underneath the suspension pick-up's but it's actually bolted through to a steel 'RawBolt' in the concrete floor.

Finally I made some little caps to allow the threads to turn once the car was in place. Very simple, just an inch or so of 25mm channel welded to an inch or so of 25mm tube.


You will also notice in this shot the spirit level that I zip-clipped in place for the sake of the photos. Since the captive nuts on the thread are all precisely the same distance from the top of the thread we can use these to set the level. the car was jacked up in stages to get all the stands lined up correctly and get the shell high enough (had to put two 4 inch thick roof beam off-cuts under the jack for the final lift) to lift it off the stands when they were at full extension. The level was then set and the car lowered before a final level check and fine adjustment with the weight on.


The level would detect anything more than about an eighth of a turn on the thread which I believe is a 1.5mm pitch so i'm happy that this a massively accurate way of doing it. The level front-to-back is largely irrelevant, like I say, were only trying to eliminate torsional distortion.


As it turns out the old girl was spot on. Well, near enough. It's touching all four stands without the need for turnbuckles but there is definitely more weight across the OSF/NSR diagonal that the other one. So for the purposes of putting a cage into a straight and true shell it's good to go, but if you were being really picky you could say it's not 'stressed' evenly. I've had a think about how this would affect the car, and if there was any ability to flex left in the shell once the cage is in, despite the fact the the shell is dead straight on level ground, it would have more resistance to torsional deflection around one direction of corner and less around the other as it is already 'pre-loaded' with a certain amount of stress across one diagonal.

The bottom line is you would have to be Ari fricken Vatanen to notice it in the handling and if you could prevent the shell from twisting completely it wouldn't even matter.

So this is where were at now


Nice and high and looking like a proper project in the making

As we say in Cornish surfing circles, I'm absolutely frothing to get stuck in to this now.

The next task is start burning out the remaining seam sealer with a blow torch. It'll be miserable work but I couldn't care less I just want spend some time on it.