[Dave] builds custom wooden orreries, which are mechanical models of the solar system. It’s no surprise then that he’s interested in the Antikythera Mechanism—a small geared device discovered off the coast of the Greece in 1900 that is believed to be the first analog computer and one of the oldest known geared systems, built partly to predict the positions of celestial bodies in the solar system as it was understood in ancient Greece.
[Dave] decided to build a wooden version of the Antikythera Mechanism as a proof of concept that it can be done in wood rather than the brass of the original. He also sought to incorporate all the modern theories of the device’s gear train. The entire system is made out of 6mm birch plywood that [Dave] cut by hand on a scroll saw. That’s right — no CNC or lasers here. This has as much to do with replicating the craftsmanship of the original as it does with practicality. Besides, the pitch of the gear teeth is too small to be effectively cut with a laser.
There are no motors, either. The gears are centrally connected to nested brass tubing and the mechanism is actuated with a hand crank. The six pages of forum discussion are worth combing through just to see the pictures of [Dave]’s progress and all of those meticulously hand-cut gears.
It took [Dave] the better part of two years to complete this work of art, and you can see it in motion after the break. With the first version complete, he has begun Mk. II which will feature all of the spiral dials and pointers of the original. If you’re interested in exploring the Antikythera Mechanism further, here is Hackaday’s own in-depth look at it.
Wow. That is incredible.
Epic.
Just curious, how can the kerf on a laser be less precise than hand cutting on a scroll saw?
A laser that can punch trough 6mm loses focus.
Not to knock his work, it’s gorgeous, but I can see no gears in there with a pitch too small for even a cheap a laser to handle. The creator said he didn’t want the burned edges, distortion and claims the lasers he has used in the past were not capable of such small teeth.
Two of those complaints can be alleviated with minor adjustments to how you use the laser. Yes, you can just punch straight through the plywood with even a low wattage laser, which I’m betting is what he has always done. However you can also cover the wood with a protective layer then make multiple passes to get a much better finish with less distortion. While there isn’t really a way to eliminate the burnt edges, considering the time saved, you could very easily hit them with a file or sandpaper to take that off, correct a bit of distortion and still come out far ahead.
I see similar complaints about 3d printers, “the finish is bad”, “they can’t do x”, “they take a long time”… You have to consider man hours vs machine time. Yes, it may take 70 hours to print something you could make in 40 hours and still require another 10 hours to finish it, but it still saved you 30 man hours to reach the same result. More importantly, the machine also didn’t need rest or food. 70 hours to machine is 3 days, to a human 40 hours is an entire work week.
Again, I’m not knocking his work, the craftsmanship is fantastic. I’m just trying to clear up some misconceptions people may get regarding the laser.
I don’t know. 3d printers take so much baby sitting. Hours spent printing are almost man hours themselves!
what most consumers think of as 3d printers are a far cry from the commercial units available, they will happily run through arbitrarily long jobs with little to no supervision.
Absolutely. There’s a reason that people involved in additive manufacturing in industry find the term 3D printing quite cheap and childish. Because that’s what most of the better known consumer machines are.
They are just (also?) afraid their industry will go the way of commercial small format digital printing when equipment is cheap and mature.
Really? I find that once a printer is tuned, I might watch the first layer, then ignore it. (Fires up software to check on a 3D printer, hrm 34% on a 20 hour job. (I did check it at 17%, just because of a similar post.) I’ll check it now, … perfectly fine.
Mind you most printers take work to get to that level.
Oh hogwash.
Use a laser on plywood – get charcoal. Period. Show me otherwise.
Even with .1mm resolution, 3D FDM parts are generally quite messy – nowhere near as nice as what this person has made.
A high quality 3D printer, which uses a laser or objet style printhead can make very nice prints – but UV stability >IS< a real issue.
Your comments are wrong, and apparently mean spirited.
Oh yeah – FILE DOWN >THOUSANDS< of gear teeth? Only to end up with manual filing and sanding marks all over the part?
Insanity. Just shut up.
And that sickening smell.. The smell is even worse than the charcoal!
Oh yeah – cost is also big with ‘real 3d printing’ – even a very low cost service beaureu will be charging quite a lot per inch^3 of print. The cost for the above device is thousands and thousands of dollars of ‘real’ 3d printing.
It may have been $200 of brass and wood.
‘What about your time’, you may protest – but look at this – you think he did this on the clock?
Do you watch 10 hours of TV a night?
I dont. I spend my time on my hobbies and interests. 100 hours is nothing to a serious hobbyist, craftsman, artist or whatever.
+1 Noirwhal. Have you seen Mattias Wandel’s work? Great example of ingenuity, working with his hands, and mostly without CNC so far.
My dad has built all these wooden clocks in the last years, by hand, gear by gear. He doesn’t even know what a 3D printer or a CNC means…:) https://www.youtube.com/watch?v=dH9MyEMhhTw
To conclude: a CNC machine would have been perfect for this project, but if wood is the desired medium, and CNC is not feasible or maybe not desired – then doing it by hand is the >only< way to get these parts.
A clever woodworker can use many labor saving techniques to make the gears.
Totally agree
I’m waiting for the LEGO Technic kit to come out.
B^)
If you build an Antikythera mechanism from lego you’ll be made king of Denmark!
https://www.youtube.com/watch?v=RLPVCJjTNgk
There you go.
Impressive build, and with dials that really prove what is all this about.
Tak, deres Majestæt!
As someone who still can’t afford a CNC manipulated laser cutter, a 2D printer, much less a 3D one… It’s nice to still see people using hand tools. If he wanted to use a saw, let him use a saw.
I often sing the praises of overkill in tools, but there’s nothing wrong with you know…. NOT using overkill either.
Why not use electronic tools? Some people like to model in 3d with saw and wood.
Wow – I’ve only just found this article, and since I’m the idiot who’s been hand cutting all those thousands of teeth I thought that i’d better first of all say thank you to Kristina for featuring my machine – it’s very much appreciated.
Right – to answer the question of why the heck I’ve done it all by hand so far. Basically, it’s convenient, relatively quick, cheap, and I have total control (…I can quickly rectify mistakes…). I’ve built lots of orreries over the years and I did have a lot of the gears for these laser cut by several different companies, and although they all worked, the quality of cutting was, on the whole shockingly bad. Not only were the edges always burned (which I kind of expected), but the laser wandered as it went through the material leading to teeth that were never quite square (this was the same from all the company’s used). The wood that they always recommended was 6mm faced MDF as 6mm ply was just too solid to cut cleanly – quite simply laser cutting was too much hassle. The gears on this new machine are also way smaller than anything I’ve done before – laser cutting simply doesn’t work with 6mm ply at this scale. And in case you’re wandering, water jet cutting is much the same unfortunately. CNC cutting is a possibility, but just needs exploring when I’ve got more time.
3D printing? I can’t afford it – and it’s plastic!! No thanks.
Once it’s properly finished I’ll be looking into methods of reproduction which don’t require 1000 hours of input from me. I’ve enjoyed every second of it so far, but I don’t think that I could hand cut many of these, they are one heck of a lot of work and I think that my eye site would start to suffer after a very short rime…
Right, I’d best get back to the shed – I’ve a machine to finish.
:-)
Hey! I think your device is wonderful.
For CNC, it wont be that expensive for a machine to only cut this sort of plywood parts. The first CNC I built for around $500 could make your gears. It will be slow though, and use a dremel which is loud!
I am surprised you had the accuracy problems with the laser. Ive used laser cutters extensively, and I am quite certain the problem isnt the ability of a laser to make the parts accurately enough. Interesting. Maybe I am misunderstanding.
Good work!
Hmm… that would be my machine then! Thanks for the article Kristina – it’s very much appreciated.
So as I’m the idiot who has decided to hand cut all those gears by hand, I guess I’d better explain why to all you more automated people out there.
To put it simply, at this scale, lasers just don’t cut the mustard. My gears are 6mm ply (as has been mentioned), and the smallest tooth pitch is just 1.2 mm. A laser would destroy most of the strength of the teeth at this material thickness. I know this as I used to build wooden orreries (big 9 planet machines with 50 or so gears), and I did go dowm the laser cutting route with these for a while, but even with relatively large 4mm pitch teeth the results from 3 different companies were never great – lots of distortion, burnt edges even with protective paper applied before cutting – and it wasn’t cheap either. They did work, but we’re never that lovely to work with.
Water cutting was much the same unfortunately, and CNC cutting is my last hope once the MK2 machine is finished, but at the small scales we’re talking (less than 1mm between the base of the teeth in some cases), I think even that might be problematic. Scroll saw cutting – not quick but it works, but I do have to find a solution before too long – I don’t think that I could hand cut too many more of these, they are a lot of work and I value my eye sight…
Right, back to the shed – there are gears to be cut!
Cheers,
Dave.