Flexible Link Necklace With Interchangeable Gems

I've been toying with the idea of making a necklace with a TPU base (because it is more comfortable and durable in thinner layers than PLA) but having a way to incorporate PLA parts since I have WAY more PLA filament than TPU filament. After finally giving it a go and doing some experimenting, I came up with my design for necklace links with interchangeable gems. Originally, I was going to have links that were added together during printing (meaning I would print some, then start a new print with a pause, and when the pause came up, I would add in the previous prints - like this bracelet), but I ended up going with this design which is made up of multiple pieces and I think it makes for a stronger design that is easier to print.

This flexible necklace is made up of TPU links that easily connect together. The links are empty because you print the gem inserts in any color using PLA (Or PETG would also work) and they can be mixed and matched in the necklace. I started with a larger hexagon diamond design and then eventually added smaller diamond shapes, sphere shapes, and emerald shapes. Then I also added earrings as well to coordinate with some of the designs.

[I actually made this a couple years ago (and had the idea a while before that) and am finally getting around to sharing my tutorial.]

Everything is designed in Tinkercad.

1. 3D Printer
2. Flexible TPU Filament - I'm mostly using Black, but you could use almost any color. I also like Gold and Silver/Liquid Luster.
3. Any other filament, I'm using PLA - multi colored filaments look nice here.
4. My files can be found on Makerworld:
5. Large Diamonds - there are also earrings
6. Small Diamonds
7. Spheres with earrings
8. Emerald Cut

*any Amazon links are Amazon Associates Links

I never printed the earlier versions, but I did play around a little before settling on my design. I was trying to think of how I could print links that would move freely from each other. The trouble was, I was worried about durability.

I also played around with the gem design trying to figure out how they could snap into place and stay while also looking nice. The first design had tab like parts on the bottom which just wasn't nice to look at.

I used pretty much all Basic Shapes in Tinkercad.

When it came to the final design, I knew I wanted little diamond gems so I needed some sort of base that they would fit in.

My base ended up being made out of a Torus with specific settings in the parameters box that made it a hexagon and worked perfectly for what I wanted.

I knew I wanted tabs on each side that would fit into each other. If I wanted the necklace to be truly flat, I would have to move one of the taps up off the Z axis, but that seemed like an unnecessary challenge and seems like it is unnoticable when worn anyway.

For the tabs, I used rectangles sticking out each side for connectors and one side has a simple torus with a flat bottom and the other side has a disc topped with an upside cone and half sphere.

I made sure these tabs would sit well on top of each other. You may notice there is some overlap with the link next to it with the torus tab, but it still works fine with the finished print.

Now I have my link and what's nice about the design is you can just print as many as you need for the length you need.

Next was the gems.

As I showed in Step 1, I had an earlier design with tabs on the bottom but it seemed kind of ugly and like it wouldn't be durable. I decided to stick with that diamond shape on top but then also continue it partially on the bottom. I didn't do any special measurements on size, but instead made the link shape transparent and sort of eyeballed how the gem would fit. I didn't make the bottom too big, just enough to latch it in place (I also did a cutout in the center/bottom of the larger hexagon/diamond gem just to save on filament since it is in the back anyway).

I made sure they would stick out the top so they wouldn't disappear in the necklace, but you could make it more flush with the links if you prefer that look.

Here is a look at some of the finished designs.

I started with a larger hexagon design, and then I went on to shrink those hexagons, turned them for variation, tried a spherical shape, and then lastly emerald cut.

For every design I left the tabs the same size partially so they wouldn't lose durability if I shrank them, but also, you can mix and match these links then. You can put hexagon with spheres, or small hexagons with large, or whatever you feel like.

I did some more variations with the sphere design for fun and did print some to try out. They can be fun if you don't want a necklace/choker that just goes straight across.

I also did some earrings which was a combination of just butting the shapes up against each other or using torus cutouts so you could use jump rings to connect them.

There isn't really anything special you need to worry about for printing. The only thing is that I made sure to do concentric infill for top and bottom of the gems for the look. Another thing to note is that I think that the textured build plate can look nice with solid colors but for multi-colored filaments I think it is better to print them top up if you can or print on a smooth plate.

These are pretty straightforward, but can be a little tricky to connect. I have a video to make it a little easier, but I found it best if you took the loop tab and stick it into the inside edge of the bump tab. Then hold that loop in place with your finger/nail and then pull the loop over the bump.

To get them apart it helps to hold the bump with one finger/nail and then kind of pull the loop tab up and over the bump tab.

The gems mostly just snap into place fairly easily.

But, yeah, the video makes it easier to follow.

I can give you a bit of an idea on sizing, but if you have questions, I can connect them and let you know. You can also see in the images that you can just add more links until you have a length you like and they can also work as a bracelet!

Large Hexagon/Diamond:

1. 13 links = 39cm or 15.35" what I'm wearing
2. 10 links = 30cm or 11.8" good for a child

Small Hexagon/Diamond:

1. Point Up:
2. 19 Links - 16.125"
3. 21 Links - 17.875"
4. Flat Up:
5. 17 Links - 15.75"
6. 19 Links - 17.625

Emerald Cut:

1. 15 links = 16.5" long

Round:

1. 16 Links = 15.5"
2. 18 Links = 17.5"
3. 20 Links = 19.5"

Here is a look at all the designs and some of the color combinations I tried.