13 Aug 2008

With the front end sorted and the axles having arrived, attention returned to the rear suspension. Push-rod rear suspension was almost considered a requirement, but after spending hours staring at it and trying different solutions, an old-school shock layout was found. However, it’s very tempting to modify the Miata upright to make it work even better, but that has to be thought about a bit more.

It’s not easy routing the chassis around the engine, and while a de Dion axle layout makes things simpler, I don’t want to settle for almost-great, may as well do the best I can. A true independent suspension is also the most flexible, for those builders who want to tinker with things – or just leave it as-is.

One thing I’ve been ignoring is how to remove the drivetrain; haven’t decided if it’s coming out the top or the bottom. I kind of like the bottom-exit solution because the drivetrain doesn’t have to be lifted in and out, scratching up chassis tubes. Just wheel something under the car for the engine to sit on and lift the car up off it. Either way it means some of the tubes need to be removable, just haven’t decided which ones yet.

I have two more days to get everything sorted (before the wife comes home) and I think it’s doable, at least by the end of the weekend. Well, “sorted” in the sense that tube placement has been decided, then it’ll take weeks to put it all into CAD. I’m concentrating on only one side of the mockup; no point doubling the work of making the other half.

I realized that it’s impossible to go straight to steel without completely recording every dimension. Since I don’t have space to set the mockup aside once steel construction starts, it has to be chopped up for firewood before I can. If I missed some critical dimension, well, that would be unfortunate. For that reason it’ll go to CAD first. Now that I’m nearly out of the hardest part of the project, I’m starting to change my mind on how to do mockups. That is, I now think it would be easier and maybe even faster to do it all in CAD (“next time”) though detailed dimensions are still needed of all major components.

While taking Cooper for his morning walk, we had another encounter with an animal. Much like the ferret from a few years back, we were walking along a trail and out of a bush came a light tan and white rabbit. It must have been someone’s escaped pet, due to the coloration and also because he walked right up to us. I thought of picking him up, but then what? Cooper, who thinks rabbits taste wonderful, had never had one actually walk right up to him – he didn’t know what to do. When he finally decided that it might really be a rabbit, it took off when he barked at it. Hope the little fellow finds his way home; being in the wild with white markings is like having a bulls-eye on your head.