Astronomical Clock with Equation of Time indication


After finishing the Hospice clock, the older clocks needed first some attention, but sometimes it is better to look than to touch, after maintenance the first clock refused to run for weeks!  Suddenly everything was normal again but I had the idea that I had spoiled the clock a little bit, that's why I decided to make almost the same clock but now with Ball Bearings and a slightly different design.




The Equation of Time is the difference between
mean Solar time and true Solar time.
Sometimes ahead, sometimes slower.
You can read the difference in time at the ring round the Sky map

 More about Equation of Time by Gerard Klijnsmit




Equation of Time engraving at the lower ring
(The hand with the Sun indicates Clock Time and Equation of time)



  Northern Horizon
(The ring with the hour engraving can be turned by hand and is set to local Winter or Summer Time)




Southern Horizon

(The hand just out of clock centre keeps the Sun in the ecliptic)



The wheel work and front plate



The completed clock  



After polishing I used hard Car Wax instead of lacquering the Plates
(For new projects I will try (Microcrystalline) Renaissance Wax)

(All smaller parts and pillars are gilded)



The Miniature Ball Bearing(s) for the 24 hours shaft



Adjustable contra weight for the Sun Hand



 Bushing mount for the Ball Bearings
(The Ball Bearings have a light push fit, drill size 4.8mm reamed to 5mm to the depth of the bearings)



Sky map with Equation of Time indication and Sun
(The design of the Sky map is from Rob Walrecht © - the Sun moves in the Ecliptic)


Turning system for the Sun



Gilding the parts, simple but it works!



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