Even if I take a screenshot and check the pixel size of the wheel for using a radius value, that doesn’t seem to really match up either. Although the fact that it is about 15 pixels different from the calculated amount should be a serious clue…
It’s probably easiest to see the exact movement when changing the rotateY(-30deg) on #machine > div to -89deg to get an almost full side view.
Hmm… it’s escaping the larger sign in the previous line. But you get the gist.
Edit – I noticed the front and back don’t match up, element-wise. Now thinking it’s an inherent design flaw but not sure how to fix it yet. Should’ve inkscaped more and use less pen and paper:
Update – it’s a “circle” alright, I’m apparently just calculating the centre point incorrectly.
Lol, visualising’s a lot easier when you can actually look at it. I’m concluding it needs both an adjustment for transform-origin depth (z) as well as the y-coordinate.