Hi Christopher, yes there is a demo function. In fact there is a two speed transmission. In demonstration mode, one revolution of the hand crank is 24 hours, this drives all of the celestial functions simultaneously, the planisphere, tellurion, orrery, Sun/Moon, and calendar. Then a second "fast mode" that disconnects everything but the orrery for 10X speed. This is done to demonstrate the movement of the planets of Jupiter and Saturn as their orbits are 11.86 and 29.46 years and so would barely move at the lower speed, but at 10x they move, however, 10x is too fast for many of the other celestial indicators that cycle daily like the calendar, planisphere and Sun/Moon indicators. You can see what the transmission looks like here: www.my-time-machines.net/astro_11-13.htm .

There are 111 gears in the orrery module. Glad you liked it.

We based the design on Mathias Hahn's original made in 1780. These were the planets known at the time. If you go to: www.my-time-machines.net/astro-06-18.htm, you will see the original and the reasoning behind our decision to use this design. Another reason is that space is limited, again if you go to the website and follow the design and build progress you will see why. Making everything smaller to fit the existing space means making all the parts smaller. In this module we begin to make wheels on the scale of a pocket watch which are the limits of Buchanan's tooling. Making parts on the scale of a watch is an entirely different realm of tooling and skill sets.

Is that also why Mars's moons are missing?

"stellar" work haha! I love it

@@sapphoenixthefirebird5063 Yes

2 21 21 Hey Andrew Sparrow, You, of all people would notice that New Zealand is missing! You get a gold 🌟 star. Stay safe, keep calm, & be well. v

There are no kit or plans. It took twelve years to build and was done as we went. It is a one of a kind that cost well over seven figures. So no there are no plans and certainly no kit. But for $2 or $3 million, you may be able to replicate it.