Hello!

For my impossible 3D-printed object, I created a spiral traffic cone that prints in two interlocking, movable pieces. The design allows the two parts to rotate around each other smoothly once printed, which makes this an oddly satisfying fidget toy.

First Attempt: SLA Fail

I originally tried printing the spiral cone using an SLA printer because I wanted to take advantage of its precision and try it out. But the friction between parts was too high, and the cone got very stuck while messing with it causing no movement at all.

Here’s a photo of the failed SLA ones:

Switched to FDM

After that, I switched over to FDM printing, using both the Prusa and Bambu printers. I printed two cones on the Prusa and three on the Bambu, sharing the print bed with Kate to save time and space.

I scaled the cone down to 60% of the original size, to fit within the capsule.

No supports were needed for the FDM prints, which was great for maintaining clean movement between the interlocked parts. Only the failed SLA version required supports (and they made it worse).

Final Outcome

The prints came out clean and fully functional. I was especially impressed with how the Prusa printer handled the spirals with no supports. The interlocking motion works beautifully now, and I love the way it feels in-hand. It’s also a fun reminder of how design choices have to match the material and printer capabilities. The brim under the prusa was mildly difficult to remove and the lines between the layers was more articulate in comparison to the Bamboo.

Cost Analysis:

Here is my cleaned up area:

I’m really proud of how this project turned out (even with the bumpy start) and excited to keep exploring more functional, movable prints like this one.