Orreries by and large approximate planetary movements to circles.

For the nit-picking pedants, the obsessive-compulsives, and the anally-retentives, this is totally unsatisfactory.

Planetary orbits are not even regular ellipses, since their orbits are affected by all the other planets; your binary planet-planetoid system orbits a common centre of gravity and wobbles around your primary in a bizarre path which is hilarious when viewed from a distance.

The BorgCo Precision Orrery is much more realistic. Using stepper motors to make fine adjustments, and deriving data from both an online ephemeris and real-time observational data, the controller constantly adjusts the representation to exactly match the actual relative positions of the various bodies.

Of course, the movements are so small as to be undetectable to the naked eye, and in real time are extremely slow. But that's not important.
-- 8th of 7, Feb 20 2016

Technically this idea describes an “accurate” orrery, not really a “precise” one. And even then it's only really accurate in the temporal dimension, as a truly size-accurate orrery would be impractical to construct.
-- ytk, Feb 22 2016


Presumably, if it were so precise, it would not be an actual orrer, as opposed to just being orerry.
-- MaxwellBuchanan, Feb 22 2016


// not really a “precise” one //

The manufacturing is the precise part, or rather parts. We have outstanding quality control (employees who produce work of unacceptable quality are made to stand outside on a plinth).
-- 8th of 7, Feb 22 2016


// the movements are so small as to be undetectable to the naked eye, and in real time are extremely slow.//

Baked. Any waiter in a Parisian restaurant.
-- MaxwellBuchanan, Feb 22 2016


//constantly adjusts the representation// ... Epicycles. This was a popular orbital calculation method here up to a couple of years ago.

Pluto's years.
-- lurch, Feb 22 2016


So, 14 years ? Pluto's quite big ... but the approximation of 1 canine year = 7 human years remains useful.
-- 8th of 7, Feb 22 2016


//stepper motors// No it has to be entirely mechanical and analogue.
-- pocmloc, Feb 23 2016



random, halfbakery