A Special Builder's Notes


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21 October 2013

That Said....

.... in preparing for the work on the scuttle, I realised that I had left undone some jobs which ought to have been finished by now and first I revisited the universal joint in the steering column - something that I knew wasn't right but hadn't made the time to properly address. Fundamentally, the male and female splines didn't match; they almost did but not quite and only examination with a magnifying glass revealed that the splines started to run out in the last quarter of the circumference. I knew what I'd done, I'd picked up the wrong joint and gone ahead without paying proper attention. Fortunately I have the correct matching female joint and I just need to machine it's shaft down to size.

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Then I remembered that the shape of the door needed to be refined so, whilst the whole frame was still together I sorted that out as well. The corners need to be radiused but I'm still wondering whether it might be better to have the outer skin slightly overlapping the body (in which case I can introduce the radius to the skin) or to have the door flush - the jury's out on that at the moment.

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The slope on the lower right corner of the door is more or less in line with the front of the seat so accessibility hasn't been compromised in any way. And, as the plan to complete the scuttle was fast receding, I made up a template for the firewall brace and made an alteration to the rear brace.

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I've added an extra arm to the cross brace so the rear longeron is more adequately tied in to the cockpit. I don't know why I first drew it up without - probably because the bit of ply I used for a template wasn't big enough. Anyway, I've added a couple of extensions and it now looks right. Putting the steel washer plates on the underside of the longerons (I know they're probably not called longerons on a car; rails perhaps?) will eliminate the need for wooden blocks glued into the corners - I'll still use the blocks in all the other corners and then, with a thin ply inner skin, the body should be really quite strong and rigid. As discussed in an earlier post, the body to chassis mounting bolts will probably have to incorporate springs to lend everything a little bit of flexibility.

Talking of which, a conversation with a leaf spring manufacturer has confirmed in my mind that the springs on the car definitely need some adjustment to the Rate of Boing - currently the rate is about zero. A couple of leaves removed from each of the rears and one leaf from each of the fronts will probably do the trick. Actually, it's a bit more scientific than that. I need to supply the corner weights and some dimensions for them to work up various moment arms which determine the Optimum Rate of Boing to cover all the theoretical load scenarios. Then, a combination of heat treatments and the removal or addition of leaves results in a Jolly Comfy Ride.

I think that's what he said.

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