Antikythera Mechanism Build.

Mechanism Man · April 01, 2015, 10:44:34 PM

Believe it or not, with the 6mm ply wood that I'm using, laser cutters are - erm - awful! I know because I've gone down this route with several companies when I was building orreries. The gears on those generally had a tooth pitch of 4mm, and the laser cutting was pretty ropey even at that size, they worked but weren't great (lots of burn and angular distortion). The tooth spacing for the gears on this new machine are just 2.5mm for most, and down to just 2mm for some, and the only way I know of cutting down to that size without resorting to a lathe and dividing head is to hand cut using a scroll saw. Lasers are just too aggressive. Obviously I could use thinner wood which would be more suitable laser cutters, but it would be at the expense of tooth strength and general stability - not good with this many gear wheels.
I'm currently just wading through the last 30 or so gears, with the biggest being 223 teeth, and the smallest just 12. Should keep me busy for a while... Then it's the fun bit - building it!
:-)

Dr. Nikola · April 02, 2015, 04:42:06 PM

You must have the patience of a saint. There should be an award presentation if you complete this amazing process!

Mechanism Man · April 02, 2015, 09:27:02 PM

Patience, hmm, possibly, but I'm in no great rush to get it finished so I'll just keep plodding along until it's done.
Below is the gear cutting progress so far - big ones done, but still lots to go. I just don't want to speed up needlessly and make mistakes, that's when it gets frustrating and it stops being fun. Right, one more gear and then bed.
:-)

Banfili · April 04, 2015, 01:58:08 AM

I am amazed!
In fact, it never ceases to amaze me just how much sheer brilliance there is loitering on this forum!

I must check - is there a musical instrument building forum on BG?

Mechanism Man · April 05, 2015, 09:29:59 PM

Almost done with cutting the gears now - it's actually gone a little quicker than I thought it would. Hoping to maybe get this rather mammoth job finished by the end of tomorrow. Still got all the spokes to cut yet, but that's quite quick by comparison!
I'm really ooking forward to starting to put it all together next.
Best I start thinking about how it's going to look I suppose. I want to try and get away from simply housing everything in a boring oblong wooden box - that's how the original would have looked, but my intention was never to make an exact copy as such (apart from the internals obviously), so I'm going to make the look of it my own. So, I wonder where I'll end up...?!
:-)

Drew P · April 06, 2015, 01:05:06 AM

A 5 sided beveled glass box with old oak for the framing and an oak base.

Mechanism Man · April 11, 2015, 10:13:06 PM

Hmm... beveled glass and oak you say... Hmm, could be, could be...
Anyhow, I've been beavering away for a few days now with the freshly cut new batch of geas, and just today I've managed to crack the moon anomoly gearing - this little group of four gears slowly rotating on a much larger gear is quite a big deal for those 'in the know'. It's what set the scientific community alight when it was first discovered on the original machine back in the 70's. Is a complicated little set up with 4 gears, all with 50 teeth, that simply drive one another, but via a clever pin and slot mechanism to provide a variable speed output, and two of the gears share a near common pivot point but with different centres... tricky...
'So what does it do?', you may be asking. Well, in a nutshell, it accurately shows the moon natural tenancy to speed up and slow down as it orbits the Earth. Doesn't sound like much, but on a machine that's over 2000 years old, and to do this little trick with a long term accuracy which means that it's predictions of the moons position and phase are correct hundreds of years into the future is, well, nothing short of stunning.
Sorry - starting to get a little over enthusiastic there... won't happen again...
More soon I hope.
:-)

frances · April 11, 2015, 10:39:14 PM

swoon!

I've seen a film about this mechanism not so long ago and was mighty impressed at the time. BTW yours is much better than the Lego version!!!

Major Vincent Smith · April 11, 2015, 11:32:22 PM

That is a rather wonderful mechanism. I have quite the thing for Orrerys, to which mechanisms such as these must be central. Interesting to hear about the history too. Carry on the nice work!

Mechanism Man · April 12, 2015, 08:04:26 PM

I've been starting to lay out the gearing today to start setting up the size and shape of the supporting frames. The output centres have got to be in the correct places so that the pointers sit in the middle of the two big spiral dials and the 3 lesser dials when it's all put together. Thankfully, the gear trains allow for quite a bit of adjustment and movement of where the individual pivots and output pointers are located, so I should be able to put them exactly where I want them.
Back to work tomorrow unfortunately, but I've got a decent amount of momentum going with it now, so more soon I hope!

Prof. Convict Archfiend · April 12, 2015, 11:51:42 PM

What an amazing build!
Loving every update!

Mechanism Man · April 24, 2015, 05:09:18 PM

All gears - cut!
Now it gets complicated... putting it all together.

Mechanism Man · May 11, 2015, 09:15:39 PM

Here is the last dry set up before I started cutting the pivot holes in the first frame - I think that I now know why there aren't more of these contraptions kicking about, it's a complex old beasty... The first few gears are now spinning merrily and working as advertised - lots more to go though.
Another pic or two when I have this batch of gears all fitted successfully.

Mechanism Man · May 30, 2015, 10:01:10 PM

It's been slow going due to other commitments (work, family, life etc, etc...), but I am most definately getting there now.
So the last few weeks has seen me finalise all the pivot points for the main portion of the gearing, and everything has been test fitted and runs just fine.
Next step - full gear train assembly - can't wait!!
Below are a couple of films of the two halves of the main mechanism gearing spinning merrily. Still some tweaking to do when it all goes together properly, but at least I know it works.
More soon I hope.
:-)
Antikythera mechanism wooden replica:

https://youtu.be/2dE5drxJv9I
Anrikythera mechanism main gear train part 2.:

https://youtu.be/5u4eW5zXXlU

Serrac · May 30, 2015, 10:20:54 PM

Quote from: Drew P on September 23, 2014, 12:22:14 AMWe need an emoticon for munching on popcorn!

Maets · May 30, 2015, 10:24:13 PM

I am actually eating popcorn as I watched the video.

Banfili · May 31, 2015, 12:10:58 PM

Beautiful work, beautiful mechanism. I look forward to seeing the whole thing running as one.

Clym Angus · June 04, 2015, 08:40:25 AM

Quote from: Mechanism Man on May 30, 2015, 10:01:10 PM
It's been slow going due to other commitments (work, family, life etc, etc...), but I am most definately getting there now.
So the last few weeks has seen me finalise all the pivot points for the main portion of the gearing, and everything has been test fitted and runs just fine.
Next step - full gear train assembly - can't wait!!
Below are a couple of films of the two halves of the main mechanism gearing spinning merrily. Still some tweaking to do when it all goes together properly, but at least I know it works.
More soon I hope.
:-)
Antikythera mechanism wooden replica:

https://youtu.be/2dE5drxJv9I
Anrikythera mechanism main gear train part 2.:

https://youtu.be/5u4eW5zXXlU

bit of an aside but if you get the chance visit this: http://www.patek.com/contents/default/en/watchArtGrandExhibition2015.html

They have the grand master chime on display (and a whole load of patek watch techs available to talk too).

Mechanism Man · June 04, 2015, 09:11:15 PM

Thanks Clym, I'll have a look when I get 5 minutes... possibly around Christmas...
And Banfili, yes - so am I. Still seems a long, long way off yet though.
So, here is the first photo of the partially test assembled machine. It doesn't yet run (as I said - test assembly only), but it's so 'blimmin complicated I just wanted to see if it all fitted together as planned before I start putting it together for keeps. There's a fair bit of gearing still to fit so I'll post another photo when it's all shoe horned together.

Still loads to do - but it's starting to actually look like something now! What it's starting looking like it's another matter entirely...
:-)

Banfili · June 05, 2015, 03:30:55 AM

Just gets better & better!

Drew P · June 07, 2015, 02:48:38 AM

!

Mechanism Man · June 07, 2015, 01:17:09 PM

...and with it's stand fitted...
I do have to say at this point that any resemblance to a 1950's space rocket is purely coincidental - honest! I didn't give it a second thought until my 13 year old daughter pointed it out. It's worked out quite nicely though I think!
Now that I'm happy that it all fits together, and I can now see where the mistakes are (mainly in the frames - but nothing at all major) I can start ripping it apart again with a view to putting it together properly so that it actually runs - happy days!

Banfili · June 07, 2015, 01:31:24 PM

Looking VERY cool!

Antipodean · June 08, 2015, 06:38:46 AM

I am gob smacked.
Very impressive I must say.
70 points for Gryffindor.

Mechanism Man · August 10, 2015, 03:46:58 PM

Sorry for the delay in transmission ladies and gentleman,
I have been momentarily distracted by a request to build a quick nine planet orrery - normal antikythera news will resume once all orrery work has ceased.
In the mean time, here for your delight and amusement, is single a photo of 48 freshly hand cut wooden orrery gears.
Thank you for your patience.

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Antikythera Mechanism Build.