Building in the Dark

There’s a specific kind of optimism that only manifests at 2am when you’re holding a freshly printed focuser housing and thinking “this is probably fine.” It isn’t fine. It’s never fine. But you will spend the next three hours finding out exactly how fine it isn’t, and that’s the whole point.

The M42 started as a sketch on a napkin, which is a cliché I’m keeping because it’s true. The napkin still exists. It is mostly incorrect.

What Actually Went Wrong (Abridged)

The first printed tube assembly had a 0.3mm error in the mirror cell seating. This is, technically, a rounding error. It is also enough to make collimation a philosophical exercise rather than a mechanical one.

The second version fixed this and introduced a new problem: the altitude bearing friction was approximately “falls over when you look at it.” Three iterations later, the Teflon pad spacing is now documented, measured, and reproducible. We call this progress.

The focuser took seven versions. The current helical design is good. Versions one through six are in a box labeled “lessons.”

What Actually Went Right

The optics. The 114mm mirror — sourced, not made — is genuinely excellent. When everything else is working (which requires patience and the right atmospheric conditions), the views are what make all the rest of it worthwhile. Saturn’s rings resolve cleanly. The Orion Nebula glows. M13 is a smear of ancient light that stops being abstract when you’re looking at it.

That’s why we’re doing this. Everything else is just getting out of the way.

Next

The Elli is the result of having opinions about everything that was annoying about the M42. Larger aperture, dual-speed focuser, better truss design. Same philosophy: light, portable, reproducible.

It’s currently printing. I’ll write about it when it’s done.