Saturday, August 6, 2011

Detailed Orrery Plans

It has been almost 2 years since my last post, which included the promise of more detailed plans at some stage, probably in a pdf. Well, obviously that didn't happen, but, I have gone one better. If a picture is worth a thousand words then I guess a detailed 3D model might be worth a few hundred pictures at least.

I'm preparing to refurbish the orrery using something a little more durable than superglue and a little more accurate than a dremel tool held by hand. As such, I needed plans. Using Google Sketchup, a free 3D modelling tool, I have created a model of orrery that is completely scale accurate. (Unfortunately, since both the pipes and the gears were in imperial, the whole thing is also in imperial scale, apologies to the 95% of the world who uses metric.) There are two versions of the model, first completed:

And also exploded:

As you can probably see from the pictures here, I have coloured the pieces so that groups of elements that are physically attached to each other are the same colour. Hopefully this will make it much easier to tell how the whole thing is put together.

A couple of notes, the worm gear is represented here just as a cylinder, couldn't work out how to generate that in sketchup. Also, I have omitted the chain between the two sprockets, again a little too fiddly. The two large gears that aren't actually touching each other are the sprockets. Finally, the gears aren't always directly connected to the tubes because the bore holes are often larger. As I mentioned previously in the blog, I would connect these by cutting small sections of tube up to fill in the bore hole.

For those of you who haven't played with Sketchup before, it took me all of about 2 hours to go from no idea to able to put together decent models. I downloaded it 3 weeks ago and have put this together in spare time since then, so it's pretty easy to find your way around.

Hopefully in the coming months I will have updates with the rebuild process of the orrery. In the meantime, for those of you out there trying to build this (and I've heard from about a dozen of you, with at least one almost finished), I hope this model makes life easier.


  1. Great to see you picked up the project again! The original orrery was pretty amazing already, so I'm looking forward to see how the refurbishing will come along.
    I'm planning to start building my own in a couple of weeks. The 3D models should come in really handy. Thanx and good luck!

  2. I have just joined your blog and found the info very helpful. I have built my own orrery all in brass but I have a few questions and wonder if you can help.

    I have cut my own gears and have compounded the 32/50 with a 48/32 so that they mesh correctly. I would like to build another with more accurancy but trying to work out the gear ratios made my brain explode !! In your Accuracy section they are very close but I wonder if it is possible to get them even closer, please don't tell me I need to use extended fractions - that is just over my head. You asked for a photograph which I am happy to do but am an inexperienced blogger and not sure how to attach this. You have mentioned that you happy for emails but I could not find an email address.

    I wonder if you have built an orrery with all seven planets, if so I would be very interested in the gear layout for this.

    Many thanks for all your help.

  3. This is awesome mate! I too would be interested in trying to get those gears as accurate as possible, any ideas? Also, do you know of any plans that feature the orerry being hooked up to a pendulum clock thus keeping exact and accurate planetary info all year long? Keep updating your blog! Cheers!

  4. I don't know if you are still following this, but I am fascinated and have plenty of questions for you, if you'd have time to answer.

    Please contact me at

  5. This comment has been removed by the author.

  6. You can change the units in the model by going to

    Window -> Model Info -> Units

    Then selecting decimals, millimetres.

    I love the blog, and am away to start making my own, hopefully making my own gears. :D Thanks

  7. Wow, these landscapes are true marvels. I hope I get the cahnce to see them up close some day.
    Brass fittings
    Wash Hose
    Oil Hose
    Mud hose

  8. Wow, only just stumbled upon your blog (only a few years behind the rest of the world - nothing new there then...), but your machine turned out great - getting the Earth to spin on its axis is no mean feat!
    Thanks for the mention in your 'inspiration' blurb - don't think that I've ever inspired anybody to do anything before, so thank you, and it sounds like you have inspired a whole new generation of orrery builders yourself, so well done for that too - the more the merrier!
    I'm just in the process of finishing off machine number 15 at the moment, I seem to have lived and breathed gear cutting for the past 6 years... good job I still enjoy it!
    Anyhow, I'll keep an eye out for future posts with interest.
    All the best,
    Dave Goodchild (the wooden orrery bloke).

  9. There are no more links to 3D models here :P Arrived too late.

  10. Me too, I would love to see some plans and have a very amateur attempt. If they could be put up again that would be a great starting point. jameskingitil

  11. The information which you have provided is very good. It is very useful who is looking for Brass Compression Fittings