Connecting Magnetic Hearts Necklace

I wanted to come up with a fun necklace that doesn't have a clasp. Instead, the two sides of the necklace would meet in the middle in the front and connect. I wasn't really sure how to approach it, but then I remembered some magnets I bought to embed in 3D printed jewelry years ago. This seemed like the time to use them!

I came up with a 3-dimensional heart design that can magnetize to another heart resulting in a fun and easy necklace that you just loop around your neck and connect the hearts together to wear it. Great for Valentine's Day.

I've tested this out a bit, and overall the hearts seem to stay together pretty well. When I laid down wearing it, they did come apart, but other than that they did well and even if they came apart, they stay relatively in place and you can easily pop them back together.

Instructable 371

Supplies

• Tinkercad.com
• 3D Printer - I have a Prusa MK3
• Filament
• Mine are Iron Red and Silky Pink
• Small Magnets - I used 3mm by 3mm by 3mm cubes, unfortunately, I bought mine about 5 years ago and I can't find anything similar on Amazon at least, but you could likely find it elsewhere or adjust your print to fit a cylinder one
• Sharpie - for marking the magnets
• Chain - mine is Stainless Steel 3x2.5mm Oval but you can use something similar
• Jump Rings - they need to be big enough to fit through the thickness of the heart, mine are Stainless Steel 7mm, 18 gauge
• Jewelry pliers

To start, take your magnets and mark them where they will fit together so you can make sure to orient them right later.

*Any Amazon links are Amazon Associates Links

First you need a heart.

I started with the basic heart in the Tinkercad Shapes Panel.

I exported it and messed around with it in Meshmixer. My original goal was to make it more faceted, and though that didn't really work the way I wanted it to, I got this nicely shaped more 3D and smoothed heart.

I cut the middle of it out using the same shape at different sizes and tried to make it look smoother along the inside instead of just a straight cut out.

Now that I have the shape I want, I needed to add a spot for the magnet and a hole for hanging it on a jump ring.

To start, my magnet appears to be just under 3mm^3. I did a test piece with a 3mm hole and it was really snug. I didn't want to have issues putting it in while it was on the print bed so I increased it to 3.2mm^3 and that worked well.

I did many tests where I would position the magnet hole, group it, export it, load it up in the slicer, and check it. Then I'd go back into Tinkercad and make adjustments based on what I want.

The two hearts aren't exact mirrors as the goal was to have the magnet as close to the surface as could while still covering it. So that means, the top heart has fewer layers below the magnet and the bottom heart has fewer layers above the magnet.

Lastly, you need a hole for the jump ring to attach to the heart. Usually, I'll just do a simple cylinder to cut it out. I've found lately, especially with thicker prints, a torus is better as you'll get the curve that will match the jump ring's curve. This doesn't matter if it's thin, but this is bordering on thick and I think the torus works better.

Now, the important part is slicing as that's where you add in the pause to allow you to add the magnet right into the print.

This will vary by slicer, but for PrusaSlicer, which is what I'm using, you go to the layer AFTER where you want the pause and right click on the Plus sign. This will allow you to add a pause before the current layer.

Ready to Print!

As long as everything works right, your printer should pause when it gets to the correct spot. Carefully put the magnet in the correct way.

[For the bottom heart, make sure your mark points up, for the top heart, make sure your mark points down.]

Add your magnet and resume the print. It should encase the magnet in without issue as long as you have space. You should be able to see when you put it in if it will fit or not. If the magnet seems to be sticking out of the hole, I do not recommend you continue the print. You should stop, put a new hole in the piece that is a little bigger and try again.

I'm usually horrible at doing test prints, but I did for this and I recommend you do too. You don't have to necessarily encase the magnet in your test print, just make sure the hole will be big enough to encase it when you do actually do the final print.

Once it is all done, you just need to attach a jump ring to each heart and connect them with a chain. Make it as long as you want. I tend to go for about 16" because I don't like my necklaces to hang down too far.