Hey Ben,
I would love to see you take on the challenge of building a equatorial mount to help ametuer astrophotographers take long-exposure photographs of planets, stars and other deep-space objects such as Galaxy's and Nebulae.
For those who don't know what an 'equatorial mount' is, it is a motorized tripod-mount-thing to cancel the effect of the earths rotation during the exposure time of a DSLR camera with telephoto lens and/or telescope.
Adding computer control could further improve the design by assisting the focusing and positioning of stars etc.
I realize this is a step up from your time lapse trolley 
but if a challenge like this what to be solved, it would benefit a lot of astrophotographers like myself.
Thanks a lot for your time. (And for making an awesome channel on electronic DIY projects)
Liam
EDIT: Picture and Caption Below, Few Grammatical and caption updates
Picture (Above): A Picture taken from a fixed tripod of the night sky. Exposure time:30 seconds. If you look closely, you will notice that the stars are slightly elongated; this is motion blur due to the earths rotation, having a equatorial mount wont only eliminate these spoils in the photographs, but will also allow for longer exposure times, and a deeper, clearer view into space. The two orange lights on the horizon are (from left to right), a city 30 minutes away and a town 10 minutes away.
