Self Build Orrery

[Mechanism Man]

No, neither of those, something far more clever (stupidly complicated...?) instead. The 13 gears refers to the total number used to transfer movement from the crank handle, through the box, and up to the earth and Moon. When I (eventually) get the photos posted you will (tomorrow morning) see the develish design.   

[rogue_designer]

No, neither of those, something far more clever (stupidly complicated...?) instead.

I'm guessing the giant earth cog is a stationary cog (roughly the size of the earth's orbit in this orrey), that as the earth is pulled around it (from the primary train), it engages a small gear system underneath the planet (secondary train), causing it to rotate. Likewise the moon is driven by the same motion.

Can't be arsed to draw a diagram. So I'll hope for the best.

*hopes I'm right*

Edit. Diagram

[Mechanism Man]

Ah ha! Got it in one! Yes, the Earth does spin on top of a small gear that in turn spins around the circumference of The Great Earth Cog. The smaller cog is 14 teeth and the static Great Earth Cog 182, that gives you 13 turns on the small cog every time it goes around the big one, which by pure coincidence is just right to spin the Moon! I then have a secondary gear train that speeds the 13 turns up to 365, and that then powers the Earths rotation. Looks pretty too!
Photos this very morning. I'll be back...

[Mr. Fish]

**(Remaining somewhat chuffed everytime someone mentions the "Great Earth Cog", and promoted to capitals no less!)**

[Mechanism Man]

Yes, I feel that The Great Earth Cog will almost certainly appear on the finished article - how could it not?
Right, children safely delivered to school, four hours before I start work, so, to the cog shop for the final gear fitment. Hurrah!

[Mr. Fish]

uh-oh,
been at least a couple of hours since any updates from Mechanism Man. I hope that the final fitment of the earth gear train is going ok... (biting nails)

[Sir Newton Bridges]

we need to have some more pics of the machine! and when its 100% finished you need to make a step-by-step guide so the rest of us can make them

[Mechanism Man]

And so, dazed and blinking into the light, Mechanism Man emerges from the cog shop - the working machine clutched in his dusty hands, a satisfied smile on his face, and the long days of frustration finally over.
Sorry, getting a bit carried away there... 
How are your finger nails Mr. Fish? Ok, so the update pics didn't come as quickly as promised. Almost thought that I'd bitten off more than I could chew with the Earth/Moon mechanism. It all looked so very straight forward, but because of the amount of gearing up that needs to be done to get the Earth spinning properly, and the very high output speed relative to the input speed, the amount of effort needed to get the whole thing going is quite high, so all the gears needed to run near perfectly to avoid it jamming solid, and for several days they didn't, so it did, if you know what I mean..
However, after several false starts, and lots of aborted frame combinations that plain didn't work, I've fanally cracked it. Still not finished by a long shot, but I now know that it WILL actually work as advertised, and not thrash itself to pieces in a hail of splintered wood, bits of gear, and bent brass rod. I've got to say that I was genuinly nervous when it all went together for the first time, would it actually work? It was such a relief to see it doing its thing I almost blubbed in a most un-steampunk way - but it was probably just a bit of wood Ether in my eye....
Anyway enough waffling on, here are the latest pitures with the Earth/Moon mech in place on the now famous Great Earth Cog....











There are are several bits that need to be altered and changed, bits that work, but that should work better if they were done in different way, so this is definately a prototype for whats to come...
Next job is to fit the handle and get it driving properly. Can't decide how many revolutions of Earth should take place for each turn of the handle, can't be too many due to the extreme accelerative forces going through the gear train when you first start winding - the wooden gears work great, but overload them too much and I'm probably asking for trouble, so I'm thinking probably one, or maybe one and a half Earth revolutions to every handle turn, but we shall see what happens after I experiment with it.
Right, must dash, I've got a tax return that needs finishing and dogs that need walking - then, back to the cog shop!   
 

[rogue_designer]

That's coming along swimmingly  - and the Great Earth Cog is everything I could have wished for.

1 turn of the handle = 1 year makes good sense from a meta standpoint... I wouldn't even find it problematic for it to be a two turns per year, or so effort, especially as I assume that would be easier on the gears (and you don't want planets to go flying off higgledy-piggledy if an over-zealous turner gets at the handle - mercury will be moving fast enough as it is).

Great work my friend.

[Herr Döktor]

Beautiful! Breathtaking! Pretty!

What sort of finish are you going to apply to the gears? It'd look lovely with some sort of tinted teak oil and a light polish!

Keep up the good work!

Herr Döktor

[rogue_designer]

I just realized, I don't know if you meant 1 or 1.5 earth revolutions around it's own axis, or around the sun.

[Mechanism Man]

What sort of finish are you going to apply to the gears? It'd look lovely with some sort of tinted teak oil and a light polish!

Herr Döktor

Thankyou for your kind words (both of you), it's much appreciated. But Herr Doktor - teak oil, now there's something I hadn't considered when it came to finishing this beasty. That may well be a very nice solution to a problem that I've been avoiding - as I've said previously, I'm worried about fouling up the teeth of the gears
if I stain or varnish. Hmm, teak oil, yes, I like the sound of that. Thankyou kindly.

[Mechanism Man]

I just realized, I don't know if you meant 1 or 1.5 earth revolutions around it's own axis, or around the sun.

Ahh, that would be around Earths own axis, not the Sun. To get the Earth around the Sun for one handle turn would probably cause the machine to self destruct in quite spectacular fashion - hospital anyone?

  

[rogue_designer]

Hah - I thought it sounded a bit quickish.

[Mechanism Man]

Yes, I don't want it to run too quickly, but at one handle turn for one and a half days it should work out fine. If you think how fast you can wind a small handle if you want to, I think that the speed of operation should be just fine.

[Mr. Fish]

Now I don't usually "hurrah" at the sight of plywood, but in this case I'll have to make an exception, therefore:


   

HURRAH!

   

[Herr Döktor]

In the Libarary of lost books lies a tome named 'Better Living Through Plywood', I'm sure!

[Mechanism Man]

In the Libarary of lost books lies a tome named 'Better Living Through Plywood', I'm sure!

I have an original first edition - its magical powers guide me...

[Outa_Spaceman]

I think I have fallen in love with your scroll work...
_{(I don't believe I just typed that)}
I am truly stunned...

[macmangan]

OH MY...  I've been away for a week and look what I have missed.  This is so beautiful, and it keeps getting better.  Thanks for taking a bunch of photos, this is what I long for.

[Alexander Edmund Clough]

Oh my word! How did I miss this thread?

That is utterly sublime. Hand cut gears. with a scrollsaw.

Fabulous stuff sir!

[Mydnight]

Sorry if someone else came up with this already (I'm just making a quick runthrough of the first page during a study break), but:

For instance, how would you begin to take into account leap years?

This really isn't that difficult; the reason leap years fall every four years is because one solar year is actually 365 days and 6 hours long -- leap years are more for convenience sake than anything else.

[akumabito]

Will the next version include the planets' respective moons and all objects from the Kuyper belt?

[Mechanism Man]

Sorry if someone else came up with this already (I'm just making a quick runthrough of the first page during a study break), but:

For instance, how would you begin to take into account leap years?

This really isn't that difficult; the reason leap years fall every four years is because one solar year is actually 365 days and 6 hours long -- leap years are more for convenience sake than anything else.

By gummy, I guess your absolutely right. A leap year is just an invention by man to keep things neat and tidy, but the time itself is set in stone, and as the orrery is just measuring time, all I'd need to do is get the gearing sorted to measure 364 days and 4 hours and I'd be there - but there's the thing, I haven't done the maths yet, but I have a feeling that the gearing would be quite complex for that exact output. But if a jobs worth doing I guess it's worth doing right.
Hmm, Mark II is just around the corner, so that may be a worthwhile mod. Right, where's my calculator?

Will the next version include the planets' respective moons and all objects from the Kuyper belt?

And as for you Mr. Akumbito, well, I think you should take yourself outside and give yourself a damn good thrashing! Then again, how many objects are in the Kuyper Belt? The mechanism would sure look pretty with a couple of hundred thousand gears...
 

[akumabito]