Member postings for Dave Goodchild

Edited By Dave Goodchild on 12/12/2016 13:48:42

I've only just been pointed in the direction of this forum and your thread. I'm really impressed work your gear work for this project of yours - a jovilabe makes a nice change from a traditional orrery - and from an historical point of view until the invention of accurate sea going clocks by the great Mr Harrison in the mid 1700's knowing the exact position of the moons around Venus was the only way of pinpointing your longitude as you sailed around the world - not an ideal navigational solution, but it worked!
Anyhow, apart from telling you how good this is looking so far I just wanted to defend the honour of the Antikythera Mechanism that you mention a couple of times - I'm not sure how much complexity your machine will have eventually, but the Antikythera really is a complex old beasty. It has several differential drives with pin and slot gearing, bits spinning within other bits, retrograde motion outputs for the five naked eye visible planets (pointers change direction from forwards to backwards and vice versa), accurate eclipse prediction capabilities, moon phase indicator, and of course there are the two big spiral slotted date dials.
I know all this as I've just spent the past two years or so building one... out of wood... Sorry, unfortunately I don't yet have a lathe in my life, or the skill to use one.
Anyhow, there are a few photo links below to show you what I've come up with - and so far it works beautifully... I just hope that my luck holds until the end.
There is still a fair bit to do before it's finished, but the mechanism itself is all done. The most difficult task will be calibrating it.
Keep up the great work, I shall be watching with interest and wishing that I had your fabrication skills!
 

Edited By JasonB on 11/12/2016 20:58:43