We like scale models here, but how small can you shrink the very large? If you’re [Frans], it’s pretty small indeed: his Micro Tellurium fits the orbit of the Earth on top of an ordinary pencil. While you’ll often see models of Earth, Moon and Sun’s orbital relationship called “Orrery”, that’s word should technically be reserved for models of the solar system, inclusive of at least the classical planets, like [Frans]’s Gentleman’s Orrery that recently graced these pages. When it’s just the Earth, Moon and Sun, it’s a Tellurium.

The whole thing is made out of brass, save for the ball-bearings for the Earth and Moon. Construction was done by a combination of manual milling and CNC machining, as you can see in the video below. It is a very elegant device, and almost functional: the Earth-Moon system rotates, simulating the orbit of the moon when you turn the ring to make the Earth orbit the sun. This is accomplished by carefully-constructed rods and a rubber O-ring.

Unfortunately, it seems [Franz] had to switch to a thicker axle than originally planned, so the tiny moon does not orbit Earth at the correct speed compared to the solar orbit: it’s about half what it ought to be. That’s unfortunate, but perhaps that’s the cost one pays when chasing smallness. It might be possible to fix in a future iteration, but right now [Franz] is happy with how the project turned out, and we can’t blame him; it’s a beautiful piece of machining.

It should be noted that there is likely no tellurium in this tellurium — the metal and the model share the same root, but are otherwise unrelated. We have featured hacks with that element, though.

Thanks to [Franz] for submitting this hack. Don’t forget: the tips line is always open, and we’re more than happy to hear you toot your own horn, or sing the praises of someone else’s work.

The intersection between “woodworkers” and “programmers” is not a densely populated part of the Venn diagram, but [Michael Schiebler] is there with his Kerf Bend Wizard to help us make wood twist and bend like magic.

Kerf bending is a fine technique we have covered before: by cutting away material on the inside face of a piece of wood, you create an area weak enough to allow for bending. The question becomes: how much wood do I remove? And where? That’s where Kerf Bend Wizard comes to the rescue.

More after the break…

You feed it a spline– either manually or via DXF–and it feeds you a cut pattern that will satisfy that spline: just enough wood removed in just the right places that the edges of the cut should touch when the bend is achieved. This means less cut time and a stronger piece than eyeballing the kerfs. It works with both a table saw blade or a tapered end mill on a CNC or manual router. You can specify the kerf width of your table saw, or angle of your end mill, along with your desired cut depth.

The output is DXF, convenient for use with a CNC, and a simple table giving distances from the edge of the piece and which side to cut, which is probably easier for use on the table saw. (Kerf Bend Wizard is happy to handle complex bends that require kerfing both sides of the material, as you can see.)

This was [Michael]’s thesis project, for which he hopefully got a good grade. The code is “semi-open” according to [Michael]; there’s a GitHub where you can grab an offline version for your own use, but no open-source license is on offer. Being a broke student and an artist to boot, [Michael] also can’t promise he will be able to keep the web version available without ads or some kind of monetization, so enjoy it while you can!

If CNCs or table saws aren’t your thing, kerf bending has long been used with laser cutters, too.

Our thanks (which, as always, is worth its weight in gold) to [Michael] for the tip. If you’re in the intersection of the Venn diagram with [Michael], we’d love to hear what you’re up to.