Perfectionist that I am, pretty much the entire car has been rebuilt this evening, apart from the engine. Not satisfied with the imprecise and uncontrollable steering, I completely rebuilt the whole assembly from scratch using my own custom design. The system I’d used yesterday was taken from an official Lego model, and used their official steering pieces, but the problem lay in their axle; because the ball joint was only one stud’s width away from the pivot point it meant that the mechanism accentuated any give in the gearing rather than compensating for it. So I rebuilt it using ‘conventional’ Lego pieces to give me a ball joint 2 studs away from the pivot point. It took some fiddling around to get it all lined up properly and get the suspension strut sitting nicely, and then some more fiddling to get it to attach to the front subframe, but we’re finally there – I have a front suspension/steering assembly that I’m happy with!
Next on my list of things to sort out was the rear axle, which just looked plain ugly. It would do the job, and would probably be mostly hidden by the bodywork once that was figured out, but I just didn’t like the way it looked or the way it worked – it just wasn’t realistic in any way shape or form. So that was stripped out too.
In its place is a rear axle that is lighter, uses far fewer pieces, and actually works more realistically too. I’ve shortened the wheelbase in the process, which should make the car turn a little easier. It’s still a live axle (which means the axle is a solid fixed horizontal bar connecting the wheels, so movement on one wheel will affect the other), but as it happens there is enough flexibility in the setup that each wheel can actually move on its own to a certain extent, despite the leading arms – technically it shouldn’t work like that, but I think it’s just loose enough to allow it. The next test will be to see if it still does that once the rear subframe has been further strengthened; I don’t think the independence is being provided by the twisting of the subframe, but increased rigidity may slightly reduce it. We’ll see.
So, I’ve got the chassis to a stage now where I’m happy with it. The engine is smoother too, having replaced the elastic bands with proper cogs. I even took the car for a test drive around the landing to see how it responded. The engine makes a reasonable noise, given that it’s made of Lego, and the suspension can handle reasonable-sized bumps on any wheel, which is good. Next time I’ll be routing the steering to somewhere useful and starting on building some bodywork around the chassis. It’s all coming together nicely!