"An orrery is a mechanical model of the solar system that illustrates or predicts the relative positions and motions of the planets and moons, usually according to the heliocentric model." -Wikipedia-

In this Instructable I will share how to make a fully 3D printed orrery of the sun, with the planets from Mercury to Saturn. The earth has a moon orbiting around it. The orrery is a combination of 3D printed parts, brass tube and miniature bearings. Optionally, the planets Uranus and Neptune are also designed, but it makes the orrery quite large and both planets hardly move. I personally don't think it is wise to make one with the last 2 planets. Most old orreries don't have them.

Optionally, using a slipring and leds, the sun can be made to light up.

A small Warning about this project. While it is not impossible to make this orrery, it is a fairly advanced project. It requires an accurate printer and knowledge about using it. Having said that, I did my best to make it as simple as possible. If you are not completely sure about your skill you can make this orrery without the moon and moon ring. This is by far the most complicated part and while it will look slightly less cool, it make the project an order of magnitude simpler.

Step 1: Design process

The orrery was designed in Solidworks. Before design however, I needed to figure out all of the gears. My original goals was to make an orrery that was as accurate as I can make it. Every planet is mounted to the central shaft. This means to sets of gears between every planet. One going away from the shaft, and one going back to it. An even set of gears means that the direction of rotation is the same for every planet.

There is a catch however. In order to get back to the central shaft after each set, the sum of the top gears and the bottom gears must be the same. If this is not the case, the gears will not have the same hub to hub distance and will not line up. In order to properly calculate the ratios with this added challenge, I made an excel sheet with all possible ratios from 10 to 40 with 2 sets of gears. I simply enter the ratio, and the sheet lights up all of the gears that will product something close to that ratio.

Accuracy of the gear ratios

The next bit is a bit technical. It tells a bit about how accurate the orrery is relative to the real solar system and what gear ratios were used. This was a good part of the design process, so I wanted to include it in this Instructable.

The orrery starts at the sun. The sun rotates differently depending on where you measure, because it is plasma, not a solid. On the poles it spins every 34.4 days, on the equator it spins every 25.05. The orrery was designed with the sun making 1 revolution being 25 days.

Mercury has an orbital period of 87,9691 days. A ratio of 1:3,5187 is required relative to the sun. The gears 30:38 and 18:50 were used to create a ratio of 1:3,5185. This has an accuracy of 99,993%.

Venus has an orbital period of 224,701 days. A ratio of 1:2,5534 is required relative to mercury, and 1:8,9851 relative to the sun. The ratios 22:39 and 25:36 are used, giving a total ratio of 1:2,5527. The accuracy to the sun is 99,963%.

Earth has an orbital period of 365,256 days. A ratio of 1:1,6260 is required relative to Venus, and 1:14,61 relative to the sun. The ratios 27:31 and 24:34 are used, giving a total ratio of 1:1,6265. The accuracy to the sun is 99,995%.

Mars has an orbital period of 686,971 days. A ratio of 1:1,881 is required relative to Earth, and 1:27,481 relative to the sun. The ratios 29:35 and 25:39 are used, giving a total ratio of 1:1,8828. The accuracy to the sun is 99,911%.

Jupiter has an orbital period of 4332,59 days. A ratio of 1:6,3051 is required relative to Mars, and 1:173,27 relative to the sun. The ratios 12:40 and 18:34 are used, giving a total ratio of 1:6,2963. The accuracy to the sun is 99,948%.

Saturn has an orbital period of 10759,22 days. A ratio of 1:2,48398 is required relative to Jupiter, and 1:430,41 relative to the sun. The ratios 19:35 and 23:31 are used, giving a total ratio of 1:2,4828. The accuracy to the sun is 99,902%.

The moon spins relative to the earth. Every rotation of the earth is 365,256 days. The moon has an orbital period of 27,322 days. A ratio of 13,3685:1 is required relative to earth. The ratio used is 136:11 is used, giving 12,3636:1. This might seem like I messed up, but this is what makes spinning gears so difficult. When the earth spins around the sun once, the moon now makes 12,3636 revolutions relative to the earth. But the earth also makes one revolution which is added to the rotation of the moon. The total is 13.3636. The accuracy to the earth is 99,963%.

The further you get from the sun, the more difficult it is to keep accurate. This orrery stays well within 0.1% accuracy on all planets and the moon. This is more than accurate enough for me. I hope no one disagrees with me on this.

<p>WOW! this is so amazing! Am i mistaken or is every single 3d printed <br>part of this project printable with the 12x12x12cm build volume of my Up<br> Mini 3d printer? Except for the huge moon ring gear on top which is bigger - would you think it is possible to print it in multiple parts and glue it together? I read your note that the project gets a lot simplet if one just leaves it out... But it would be so cool to have it... This would <br>be a dream come true, to be able to make an orrery like this myself...</p>
<p>After studying the parts some more i see that actually all parts are printable on my up mini, you even made the moon ring in 4 parts! So, another question: does the moon ring add a lot of &quot;instability&quot; to the orrery - might it break much more easily with it in your opinion or is it &quot;once properly installed&quot; done and stable? And one more: Do you think this orrery would also work installed on the ceiling (upside down) or would the mechanism stop to work properly when it is driven upside down? It would be awesome to have this on the ceiling as a kind of light source!</p>
<p>The moon ring is one of the more fragile parts but I have not ever felt like it would break. The main argument would be that it is a really complicated part to install.</p><p>In principle the orrery should also work upside down but at this point I do not know if all axes will remain in place with the orrery upside down, but they can be secured in place.</p><p>It would be an amazing lamp. Bear in mind that the feet will need to be glued in place or replaced is mounted upside down.</p>
<p>I'm considering making this, but I'm looking to do it on a lathe and mill. I think I have all the tools required for the job, but to be sure, I'd really like to know the module values of the gears. I can't seem to find anything that looks module-value-like in that spreadsheet you attached, but I figure you must have calculated it, surely. Do you still have it laying around?</p>
<p>Not exactly lying around, but I do have them yes. The module on most of the gears is 1. The big ring and the tiny gear on the moon have a module of 1.25 to make the scale work out. If you need anything more let me know.</p>
Thanks :)
<p>Congrats on winning first prize! </p>
<p>Hard not to love this, great build and thanks for sharing the Ible, voted :)</p>
<p>This is wonderful! I'd considered designing an orrery (and started to research it), but I had a baby instead!</p><p>Did you consider a 3D printed template for the metal pipes? Maybe it's not really needed, but printed channels might make accurate bending a little easier.</p>
<p>I made the paper template. It provides more accuracy than the orrery requires. I tried making a pipe bender but after I discovered 3mm pipe can still be bent by hand without collapsing I ditched the idea.</p>
Great job. With that size of tubing you can plug one end of the tubing, so there's no air inside, after it's submerged in a soapy water solution and stand them vertical in a piece of foam and freeze them and then bend them. The soap helps eliminate some of the friction and the mixture keeps it from collapsing. Keep up the great work and the inspiration.
<p>I have had little problem with this size tubing, but I will remember that when it is more critical or when I need to bend bigger tubes. Thanks.</p>
<p>A baby is WAY more complicated and takes ever so much more time and there are so many more unpredictable moving parts for me, smile.</p>
Amazing orrery !! <br>can you plz give us your excel sheet for calculating gear sizes<br>thx
<p>I don't know how much use it will be, it is quite chaotic, but I added it as an attachment to Step 1.</p>
<p>wow, ouch, oh god! That is a great piece of work sir. what would it cost for you or someone similar to make the parts available for sale as a kit? would make a great instruct-able kit for a classroom or a die-hard hobbyist.</p><p>thanks for sharing! </p>
<p>I don't think I myself could make this a kit for an interesting price. I charge somewhere between 5 and 10 euros per hour for 3D printing, and printing takes at least 10 hours. Other materials come to roughly 20-30 euros. Think around 100 euros, but that is from the top of my head.</p><p>Classroom might be a bit challenging, but die-hard hobbyist should be fine.</p>
<p>Brilliant work. But if we want to set it to be 'accurate' and match a given date. How do we do that ?</p>
<p>That is a problem I did not solve. The 'easiest' way of doing it would be assembling the planets as it is right now, but sadly you cannot slide the planets in their current position.</p>
<p>I'd suggest you add it to competition on Thingiverse also</p>
<p>I don't do thingiverse anymore. Short version is that I lost all of my goodwill toward Stratasys and Makerbot, and stopped using it.</p>
<p>I love your project! As a science teacher, this would be a great thing to build for my classroom. I do make a point to my student that an orrery only relates the relative positions, but not the distances between the planets. Paul Doherty of San Francisco's Exploritorium has a great &quot;snacks on the relative sizes &amp; distances between the planets of our solar system: http://www.exploratorium.edu/ronh/solar_system/</p>
<p>I would like to have made it with the right scale and distance planets, but I am afraid that both my 3D printer AND my house are not big enough for that. Even with the examples I have seen I myself have a hard time grasping just what the scale really is. </p>
<p>GREAT JOB GREAT PROJECT</p><p>I just ordered a 3D printer. I would like to upscale this slightly, and I am hoping I can do this through the STL files you give, upon importation, before slicing then printing.</p><p>I worked at a Planetarium here in California for 5 years (2008-13) where I presented programs to K-12 on Field Trips - A terrific job before I became disabled. I would have loved to had one of these on display.</p><p>Thanks Again, Your Analysis is also appreciated - Something not typically found in many Instructables.</p><p> Bill Lewis, San Jose CA </p>
<p>You can upscale any model before slicing, but there are bearing holes and shaft bores that need to be more or less what they are now. If you want to scale it up much (think more than 5%) you will need to modify the parts so that they themselves are bigger but the bores and bearing holes aren't.</p><p>I still have the source files available and can share them if you have solidworks. I can share Step files if you have a program that can handle them. If you don't have this software and still need it up-scaled, I might be able to do it, but it might take a while.</p>
<p>This thing is totally awesome</p>
Nice job ! I&acute;ll surely make one of those soon for my kids ! Good luck with the contest.
<p>I made an Orrey system like this also using solidworks but i make mine out of legos. I made individual lego pieces and gears on solidworks and put them together to make the system that runs off a battery powered motor. here is what mine looks like. great job by the way. I love the use of excel for the gearing. I did all mine by hand and that was a challenge.</p>
<p>Making one out of legos is way more complicated than 3D printing one. Lego gives less options for the used gears. You have my respect. I too did the gears by hand first, but that took forever and at some point I was completely done with it. The excel sheet is not perfect but it only took me an hour, so it was totally worth it.</p>
<p>Alright this is amazing! Did you consider painting the planets? </p><p>Also, I'm really glad you put in all the information you used for the design. I've been looking into orreries for a while now, inspired by this watch: https://www.youtube.com/watch?v=sw5S2-T-Ogk and I've been working on a prototype on a small clock, this definitely helps! </p>
<p>I did consider painting the planets but getting them to look good would have been difficult with my tools. Instead I printed the planets in Bronzefill and polished them. This gives a different look, one that I am quite pleased with.</p><p>I am curious to see what you will come up with. If you need any more information you can always ask. </p>
This is cool! Magnificent!
<p>Awesome instructable. </p>
<p>Great 3D Printed Model Solar System! Did you put the bronzeFill pieces in a tumbler?</p>
<p>I did. It is the easiest way to get bronzefill to shine so I designed and made a small motorized glass jar with screws. It is not the fastest but it does work.</p>
Great project and very well documented.
<p>I totally love this!!! Great work, you've got my vote!</p>
Ambitious and totally awesome.!!!

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