Mini Articulating Spine Keychain by DaveMakesStuff

Last crawled date: 2 years, 10 months ago

These print-in-place “mini spines” are fun to print and feel really weird to hold and move. Use them as keychains, fidget spines, or offbeat decorations.
Two five-vertebrae chains are included, one with a loop at the top and one without. Separate vertebrae are provided to make your own chain as long as you want!
The spines must be printed as oriented, with the spinous processes point up. Changing the orientation of the file will result in improper printing of the inner ball joint between adjacent vertebrae.
The transverse processes that stick out sideways to not need support. Therefore, you only need to support the base of the vertebral bodies and the “loop” if you are printing files with a top loop.
In order to adequately support the curved bottom surface of the vertebral body, try raising the object 3mm off of the build plate, and using the “Line” support in Cura, with the density increased to 40%.
After printing there will be some small adhesions on the inside ball joint and in the facet joints. Just do some gentle spinal mobilization and they will release and move freely. Be sure to let your print fully cool first! If the plastic is still soft, the connector may break when you try to move it.
To build your own, import the number and types of vertebrae that you’ll need to the same origin point within your software of choice. Leave the top vertebrae at the origin, and move the rest of the vertebrae back in increments of 15mm (i.e. move the second vertebrae 15mm, the third vertebra 30mm, and so on.) You can make the spine as long as you want, limited only by the size of your build plate.
Note that these are not anatomically correct! For design purposes, each vertebra is modelled off of the same vertebra, L3. The vertebral foramen has been filled in to provide strength and minimize overhangs, and the articular processes have been considerably reshaped to allow smooth movement.
If you are looking for more anatomically accurate spine models, please check out some of my other models.