This is an armillary sphere sundial aka equatorial sundial. It's adjustable to your latitude for increased accuracy. And by accurate, I mean it's a miniature made on a 3d printer so don't expect swiss time keeping. However, all the angles are correct and it will show the right(ish) time of day.

• Functional: it works! Tells time using the position of the sun
• Adjustable: from 0° to 75° to match your geographic location for increased accuracy
• Educational: makes a great teaching tool (if you make these for a class and would like printable assembly instructions, please let me know and I'll put something together).
• Two versions: one for use in the northern hemisphere, and the other for the southern hemisphere.
• Multiple “fit” sizes: print profiles contain pre-adjusted tolerance for looser or tighter models. Something still not fitting right? Drop me a line and I'll be happy to make changes or create additional sizes.
• No sprue model: for those that prefer not to print the frame around the kit, all parts are available separately in their own print profiles. They also include pre-adjusted tolerances for a looser/tighter fit.

IMPORTANT: your plate choice and cleanliness is vital to successfully printing kit cards due to their small details. When printing these types of models, I highly recommend a smooth High Temp PEI plate. Textured plates are “ok” but can cause parts to not fit as well because they create an inaccurate first layer. Above all else, your plate must be 100% clean (no skin oils).

Print Instructions

Note: the filament you choose will make an impact on readability and durability of the sundial. Silk filaments can obscure the shadow due to their sheen and PLA can deform if left in hot sunlight. If functionality is more important than form, then solid colour PETG will be best.

1. Choose the print profile that matches your geographical location:
   • Above the equator: Northern dial
   • Below the equator: Southern dial
2. Print the tolerance test first (included in every profile). This will let you know which “fit” size to choose. The two pieces should snap together snugly.
   • Too loose: print a tighter variation
   • Too tight: print a looser varation
   • Just right: print the default size
3. Print the model using my recommended settings (included in the print profile, see below for a list).

Assembly Instructions

Before you begin:

1. Carefully detach the pieces from the card with side cutters, a hobby knife, or sharp pointed scissors. You can twist them off, but just be aware that the sharp points of the sprue can cut your fingers (ask me how I know). If you choose twisting instead of cutting, you may still need to trim the plinth so it can snap into the base.
2. Inspect the parts and trim off or remove any stray bits of filament or sprue remaining.
3. Follow the assembly animation to the right. Pieces should snap together snugly. The round base may need some extra force if it's a bit too tight. If the base is a bit too loose, a bit of super glue will help keep it in place.

How to Use – Quick Start

1. Point the gnomon (the arrow) towards true north or south depending on if you live above or below the equator. Use a phone app to help you and not a compass. Compasses point to magnetic north which is not the same as true north/south.
2. Rotate the ring to match your latitudinal location. I live along 47°N, so I would rotate the ring a little beyond 45°.
3. Observe the shadow cast by the gnomon. It should fall near the time of day at your location.

Tips

• Daylight saving time (DST): all sundials will be one hour behind if DST is in effect. DST starts in mid March and then ends in mid November. Normally we would adjust our clocks to match but unfortunately sundials cannot be adjusted because they use the sun's position which doesn't care if we're saving time or not. It's kind of rude tbh.
• Time is a little off: the gnomon (the arrow) needs to be centered to the latitudinal gear. Double-check that it's snapped fully into place.
• Can't find true North or South: if you're not able to find the direction to point, you can “cheat” by turning the whole sundial until the shadow cast on the equatorial ring matches your local (non-DST) time.
• Hard to see the shadow: dials printed with silk PLA can be difficult to read because they create a reflective surface. Plain white PLA will show the shadow the best.
• The shadow is too thick: The nature of 3d printing means that the gnomon had to be thick for practical reasons. If you're using these kits in an educational setting and want a bit more accuracy, try using thread or thin string in place of the gnomon. There are notches on the latitudinal gear that string can be wrapped around; just don't tie too tight or it will cause the bow to bend.
• Gear is sticky: double-check the channel is free of stray bits of filament. Sticky gears can also be caused by the two sides of the stand pressing too closely together. Pressing down on the top of the stand can flex the sides enough that the gear will spin freely. Alternatively, pulling the latitudinal gear upwards can also help provide a little more clearance. Lastly, if the retaining ring is too tight, it can also cause the gear to stick. Reprint the ring in a slightly bigger size and try again.
• The numbers are hard to read: because of the size of the model and the thickness of the stock nozzle (0.4mm), small details can be hard to read. If this bothers you, you can reprint using a smaller layer height and/or use a smaller nozzle. Your print time will increase so be warned.
• Print Issues: see below for printer-specific tips.

Recommended Print Settings

All my 3mfs have my recommended print settings. They're listed here with an explanation of why I chose them.

Printer Troubleshooting

Model doesn't fit together or is too loose

How well the model fits together is dependent on machine, filament manufacturer, and filament type. There are limitless combinations of these three things and so it's impossible for me to guarantee a one size fits all model. A miniscule difference in flow can mean the difference between something fitting or not fitting. If you find the model isn't fitting properly, here are some suggestions:

• Try a different size: there are a number of other sizes included in the print profile, try one of them to see if the fit is any better
• Calibrate your filament: uncalibrated filament can cause fit issues. There is a “calibration” button in Bambu Studio (not Handy) with instructions on how to perform it. It is easy to do and doesn't take a lot of time.
• Try a different filament type: Some filament types fit better than others. This is because not all filament types flow the same way and can lead to minor differences in dimensions.
• Adjust the XY hole compensation: If you're comfortable with adjusting slicer settings and none of my other sizes have worked for you, you can further adjust the XY hole compensation yourself.
• Ask for changes: If all else fails, please let me know if there are certain parts that can be tighter or looser. I'm happy to make adjustments and provide updated/new profiles.

Parts came loose from the bed: There are many reasons why this may happen. These are just some of the reasons and suggested solutions.

• Correct plate: Check that the correct plate is selected in Studio for your printer. My plate(s) may be different from yours.
• Bed is dirty: Even if it might appear to be “clean,” dirty beds are the number one reason for adhesion failure. Wash in sink with warm water and plain dish soap. Don't touch the surface of the plate with your skin; move it by your fingertips and be careful not to brush it when removing prints. Skin oils transfer quickly and can cause parts to peel off. If it's been awhile since your last wash, you might want to do it again before attempting to print the number tiles. You can maintain plate cleanliness by wiping between prints with a clean lint-free cloth and 99% isopropyl alcohol.
• Filament: wet filament, old filament, silk filaments and just some filament in general can cause adhesion problems. Drying the filament or trying a different roll can sometimes help. If the filament is new and dry, try bumping up the plate temperature in the filament profile by 5 degrees to a maximum of 65 for PLA.
• Cooling: if your printer has an auxiliary fan, edit your filament profile to turn it off (set it to 0). Uneven cooling on flat parts can cause them to lift.
• Glue: Gluestick or other 3d printer safe adhesive can help stubborn parts stick to plates.
• Plate type: if the models keep stubbornly lifting off of the textured plate, try a flat plate instead. This tip is especially for unenclosed printers where ambient air temperature can cause uneven cooling. The nature of textured plates means that small detail models don't have as much sticking force and can be the most susceptible to lifting. Smooth PEI plates work better for small details because they have 100% contact with the part.

About the Model

Armillary sphere, Encyclopedia Britannica (click link to view annotations)

Spherical sundials trace their lineage to ancient armillary spheres. In the simplest terms, armillary spheres are a combination of interlocking rings that represent a map of celestial objects. Astronomers in China and Greece first began using them to observe the heavens as early as the 4th century BCE. The first spheres were simple and likely made of wood. As they became more intricate, brass was used instead to make sturdier versions. The word “armillary” comes from the latin word for armlet, a type of ring worn about the arm.

When I first began designing this kit, I did so as a joke. I thought it'd be funny to have an emergency sundial ready to go in your pocket at a moment's notice. However, the more I researched, the more I thought the idea could be executed thoughtfully and hopefully become a teaching tool much like the ones of old.

I chose an armillary style of sundial because it's a beautiful instrument. Plus, I liked that it could be adjusted to match the user's geographical location (unlike the more “traditional” flat dials that are most commonly found in gardens). In researching examples, I fell in love with the half-sphere style. To me, the wide open arms suggested the enormity of the sky. It appealed to my aesthetic and I felt I could recreate one of my own.

It took a few weeks of prototyping and stepping outside of my comfort zone, but the result is what I'd hoped for when I started: it works and it doesn't suck! I know it's not a very high bar; I just like to manage my expectations.

Lastly, a shout-out (shout down?) to sprue design. I despise designing them because I like everything neat, tidy, and square. Trying to organize weird not-square shapes into some semblance of order gets my anxiety going. It took a day and some out-of-the-box thinking but I got there in the end.

Sundial Mottos

Sundials created in the 16th century and beyond often have a pithy motto engraved upon them by their maker. They range from sentimental ("I only tell of sunny days") to poetic ("life is but a shadow: the shadow of a bird on the wing"). You can read more of them over on Wikipedia. I was going to engrave a saying as well but, alas, the model is too small. I include it here because I think it's awesome despite what my teenager says.

Tempus fugit velut sagitta;
muscae fructum velut bananam.

(translation)

Filament used in display models:

• Glorious Gold Silk PLA (Spectrum)
• Spicy Copper PLA (Spectrum)
• Basic White PLA (Bambu)

How to Support Me

If you like what I make, I would love it if you would please click the like button and/or download a print profile. If you really like what I make, then please consider buying me a coffee. Thank you so much!

Changelog

March 1, 2024

• Fixed separate parts files to include missing gnomon (arrow)

February 29, 2024

• Fixed STL upload mistake (separate part STL included only southern hemisphere, have since updated name and added separate part STL for northern hemisphere)
• Updated photos

February 28, 2024

• Updated photos
• Added note about PETG
• Added STLs for my non-Bambu friends <3

February 27, 2024

• Initial Upload