This is an Christmas snowflake/spinner decoration that is designed for bullet pixel (WS2811/2) which are then controlled through some sort of sequencer (eg Xlights, WLED etc).

It uses oval PVC electrical conduit (tube), which is common in the UK. Size of the conduit is 23mm wide by 11mm thick. Using Oval conduits makes it easier (than round tube) for drilling it for the pixels, also the 3D printed part are designed to "lock_in" with the tube and pixel.

The pixels can be held by clipping in the back, with the back side of tube drilled at ~12mm and the other side at 8 mm to allow the LED to poke through the front. Using a step through and carefully controlling i the depth of cu, t you can do this in a single action. See the sectioned picture , which shows the pixel in place in one of the holes. This, I think, makes for a neater finish.

As can be seen by the drawing there are opportunities for extending the size. The starter size works out to be about 650mm (26") diameter, and takes 113 pixels. The extended one shown, uses the same size interjoining tube lengths as the starter size, but will end up about 940mm (37") dia and uses 233 pixels. You can vary the shape by modifying the lengths, but it is all designed around the angles printed. Pixel spacing is 35mm on the 3d printed parts, and continued this along the tubes.. I have included a drilling/sizing template for the shorter tubes. The spinner "end - legs" can be made any size you wish.

I put some fixing holes in the middle fitting, but not sure if these are needed. You could just use some tube clips (yes.. they do matching oval clips) on three of four of the legs to hold it to a wall.

Happy to answer questions. .. and please acknowledge if downloaded and used.

I have also posted a xmas minitree using pixels and the same oval conduit... https://www.thingiverse.com/thing:5007461