COEDEN NADOLIG Spiral Christmas Tree — 3D Print STL Files (Digital Download)

Check this first

At full size you want a printer with 250 mm of build height. The spine prints standing up at 239 mm — it is the only tall part in the kit. Everything else is 53 mm or shorter, and the widest part is 170 mm, so a 256 mm bed is plenty.

Shorter printer? Scale the whole kit down and it still screws together — the threads scale with everything else. At 80% the spine is 191 mm and the tree is 272 mm tall; at 70% the spine is 167 mm and fits practically anything. Scale every part by the same percentage and don’t go below about 70%, where the clearances get tighter than your printer’s own tolerance.

The bands

A basket weave, generated rather than embossed

Each band’s skirt carries diagonal ridges that swap direction cell by cell, so the eye reads strands passing over and under one another. It is built into the surface itself rather than stamped on top of it, which is why it comes out crisp at 0.2 mm, adds no print time, and needs no supports.

Every band prints on its wide end, weave upward. Four internal ribs tie the skirt to the threaded hub, and 4 mm of that hub shows as a dark gap under each band — the rhythm that makes the stack read as a tree rather than a pile of rings.

Unscrew it in January and the whole thing packs flat. Nothing is glued and nothing is permanent.

Two toppers

A star, or Y Ddraig

Both toppers are in the kit, and both drop into the same cross slot in the top of the tree — so print one, or print both and swap them over.

Each is two flat plates that cross at ninety degrees. A single plate is a 7 mm sliver seen edge-on — from the side it simply disappears. Crossed, you get something that reads as a solid object from every direction, and it still prints flat on the bed with no supports.

The Welsh dragon sits inside a hoop, and the hoop is not decoration. It catches the nose, the tail, the wing tip and the feet in nine separate places, so nothing thin is left hanging off the tree and nothing can snap. The second hoop carries a six-point star. Together they make a bauble with a dragon in it.

In the download

13 files and a manual that actually explains it

Weights are estimates at 15% infill, 0.2 mm layers, 3 walls. Slice on your own profile for real numbers.

Designed and test-printed in Swansea

Every part in this kit was printed, held, rejected and redrawn before it went on sale — the topper alone went through five versions before it stopped wobbling. If something doesn’t fit, email me and I’ll fix the file, not the excuse.

Nadolig Llawen. — James, 3DFLO