Daylight Year Crown: A 52-Week Data Sculpture
A ring of 52 bars, one per week, each as tall as that week's daylight, so the rim rises and falls like a slow wave and glows round a tealight.
Daylight Year Crown: A 52-Week Data Sculpture
A ring of 52 bars, one per week, each as tall as that week's daylight, so the rim rises and falls like a slow wave and glows round a tealight.
Date: 2026-11-11 Category: Art and Decor Modeling difficulty: Intermediate Estimated print: ~7.5 h total · ~118 g PLA (estimate) Suggested price: $35–$70 printed · $7 digital file (estimate) Status: Concept
Description
The Daylight Year Crown is a round table sculpture. Fifty-two thin vertical bars stand on a ring of radius 72 mm, one for each week of the year, starting with 1 January at the back and running clockwise. Each bar's height is 6 mm for every hour of daylight in that week at 45 degrees north (the default latitude). The shortest bars, about 51 mm, mark the winter weeks. The tallest, about 93 mm, mark the middle of the summer. Seen from the side the top edge is a smooth wave. Seen from above it is a crown.
A flameless LED tealight sits in a recess in the centre. Its light passes through the 2 mm gaps between bars and throws a striped pattern on the table, so the year of light is projected back as light. Because the height rule is a formula, the same model can be rebuilt for any latitude: a Reykjavik crown has bars that nearly touch the base in winter, and an equator crown is almost a flat ring.
The default build is a single print with no supports, finished in one colour. The bar heights are listed to 0.1 mm in design-spec.json so a modeler or script can build it without redoing the maths.
Why it sells
This idea is chosen on taste, not sales. The inspiration is physical data visualisation of sunlight. John Kuiphoff turned a location's sunlight data into wooden sculptures with a generator for other places (Boing Boing, 2020-12-18, Make:, 2020-12-17, TCNJ, 2020-12-18). Valokalenteri maps daylight duration per day on a printed calendar (Conceptual Devices), and A Year of Light plots day and night by latitude as a circular map (Andrea Garrec). I did not find a printable ring of daylight bars in that search, so the gap is a simple, one-colour, tealight-lit table piece with an exposed formula.
Who buys it
Someone who likes data art, astronomy or a place-specific gift: a person from a northern city, a gardener, a sailor, a teacher. It suits a mantel or windowsill, and it makes a good gift for a solstice, a wedding or a move, with the latitude of a meaningful place. Sold through Etsy and gift-focused shops.
Design overview
- The one surprising thing: the rim is real data. Bar height is 6 mm x the day length in hours for that week at the chosen latitude, so the shape is the year of daylight.
- 52 bars on a 72 mm radius ring, 6.4 mm wide and 3.0 mm thick, with 2.3 mm gaps between neighbours.
- Bar 0 (1 January) sits at the back (+Y); weeks run clockwise.
- Central 39 mm recess holds a 38 mm flameless LED tealight, so the light projects through the bar gaps.
- The formula is in
README.mdand the 52 heights are indesign-spec.json; changing the latitude regenerates the heights. - One print, no supports, no hardware beyond the LED tealight.
Dimensions
| Measurement | Value (mm) | Notes |
|---|---|---|
| Overall width (X) | 160 | base diameter |
| Overall depth (Y) | 160 | |
| Overall height (Z) | 97.6 | 5 base + tallest bar 92.6 |
| Base thickness | 5 | 1.0 mm top chamfer |
| Bar ring radius | 72 | to the bar centre line |
| Bar width x thickness | 6.4 x 3.0 | tangential x radial |
| Bar spacing | 8.7 | centre to centre along the ring, gap 2.3 |
| Tallest bar | 92.6 | bar index 24 (week of 21 June) |
| Shortest bar | 51.4 | bar index 50 (week of 20 December) |
| LED recess diameter / depth | 39 / 3 | for a 38 mm tealight |
Parts list
| Part | Qty | Material | Size X×Y×Z (mm) | Print orientation | Supports |
|---|---|---|---|---|---|
| Daylight crown (base and 52 bars, one print) | 1 | PLA | 160×160×97.6 | Base bottom face down, bars vertical | none |
Hardware and non-printed parts
One flameless LED tealight, about 38 mm diameter x 13 mm tall, battery powered. Do not use a real candle: the bars are PLA.
Fits and tolerances
LED tealight (38 mm) in recess (39 mm): loose drop-in fit, 0.5 mm per side so it can be lifted out to change the battery. There are no other mating parts; the bars are printed into the base.
Modeling guide
Origin: centre of the base's bottom face. +Z up, +Y towards the back. Bar index i is placed at angle i x 6.923 degrees, measured clockwise from +Y as seen from above, so bar 0 is at (0, 72). Height rule: h(i) = 6 x D(n) with n = 7i + 4 (day of year at the week's middle) and D from the sunrise equation at latitude 45 degrees (Sunrise equation): declination = -23.44 deg x cos(360/365 x (n + 10)), D = (24/pi) x acos(-tan(lat) x tan(declination)). I computed these with that approximation, so they are accurate to a fraction of a degree, not to an almanac. Heights in mm for bars 0 to 51: 52.2, 53.0, 54.2, 55.6, 57.2, 59.0, 61.0, 63.1, 65.2, 67.4, 69.7, 71.9, 74.2, 76.4, 78.6, 80.8, 82.9, 84.8, 86.6, 88.3, 89.7, 90.9, 91.8, 92.4, 92.6, 92.4, 91.9, 91.1, 89.9, 88.5, 86.9, 85.1, 83.1, 81.1, 78.9, 76.7, 74.5, 72.2, 70.0, 67.7, 65.5, 63.4, 61.3, 59.3, 57.5, 55.8, 54.4, 53.2, 52.3, 51.7, 51.4, 51.6.
Crown
- Circle diameter 160 on XY, extrude 5; chamfer the top outer edge 1.0.
- Circle diameter 39 on the top face, cut 3 deep (tealight recess).
- Sketch one bar on the top face: rectangle 3.0 (radial) x 6.4 (tangential), inner face at r=70.5, centred on the +Y axis.
- Extrude it to the height for bar 0 (52.2); circular-pattern 52 times at 6.923 degrees, clockwise; edit each copy's extrude depth to its height from the list above (in OpenSCAD: loop i from 0 to 51 and
rotate(-i*360/52) translate([0,72,5]) cube([6.4,3,h[i]])with cube centred in X). - Fillet the bar top edges 0.5.
Print settings
| Setting | Value |
|---|---|
| Material | PLA, sand or warm white (a plain colour shows the wave best) |
| Nozzle | 0.4 mm |
| Layer height | 0.2 mm |
| Walls / perimeters | 3 |
| Infill | 15% gyroid (base only; bars print solid) |
| Supports | None |
| Brim / adhesion | Brim 5 mm to hold the tall thin bars |
| Notes | Use one slicing object. If bars wobble at the top, set a 40 mm/s outer wall speed and slow the last layers. |
Assembly
- Drop a flameless LED tealight into the central recess.
- Place the crown on a table with bar 0 (1 January) at the back, and switch the light on in a dim room.
Variants and upsells
Parametric variants: latitude (default 45), bar count (26 for a fortnightly version; a 365-bar daily version would be too fine for FDM), height scale, and a second ring for sunrise time. Series idea: pair crowns for two cities as a gift set. A tall 180 mm version with a lamp kit inside is possible if the bars are thickened to 4 mm.
Selling and distribution
Etsy suits a personalised version: offer the buyer's latitude and recompute the heights. MakerWorld and Printables suit the base file with a latitude parameter. Price the print as material plus about 7.5 hours of machine time and a margin, $35 to $70 (estimate). Sell the file under a commercial licence; offer a CC BY-NC free version.
Keywords: data sculpture, daylight sculpture, solstice gift, 3d printed data art, sunlight visualization, tealight holder, year of light, latitude gift, astronomy decor, personalised data art, mantel sculpture, kinetic shadow lamp.
Risks and IP notes
- Tall 3 mm bars can snap at the base if knocked. Mitigation: 0.5 mm top fillet, 5 mm base, tell buyers it is a shelf piece.
- Fine bar gaps (2.3 mm) can fuse if the printer over-extrudes. Mitigation: print a 5-bar test strip first.
- The formula ignores refraction and elevation, so a bar can be a few minutes off the almanac. Mitigation: label it as astronomical day length, not a sunrise table.
- Data sculptures exist (Kuiphoff). This one is a different shape with a different rule; no logos or text, so low IP risk.
Resource links
- Wooden sculptures showing solar dataviz for your location (Boing Boing) — Kuiphoff's sunlight data sculptures
- These Blobs Are Actually Clever Data Visualizations (Make:) — Write-up of the generator and the physical pieces
- Professor Kuiphoff invites you to share your own solar visualization (TCNJ) — Source page from the artist's university
- Valokalenteri, the Calendar of Light — Day length mapped to length and width on a calendar
- A Year of Light (Andrea Garrec) — Circular map of day and night by latitude
- Sunrise equation (Wikipedia) — The formula behind the bar heights
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