While packing merch for a recent gig, I realised I had the opportunity to do something a little fun. I’d released an album on tape, and spent a little extra to ensure the cassette itself was a thing of beauty. It deserved to be seen, rather than hidden away in a case on a shelf. I wanted to turn this piece of musical media into a necklace.
Of course, cassette tapes aren’t meant to be used in this way. Simply throwing a chain through the cassette would lead to tape reeling out everywhere. Thus, I fired up some CAD software and engineered a solution to do the job! Here’s how I built an adapter to turn any cassette tape into a cool necklace.
Find the design on Thingiverse, and more details below!
Wear it Proud
My plan was simple. I would create a plastic device that would insert into the two reels of the cassette tape, holding them in place. A pair of caps would then be screwed on from the other side to hold the plastic device in the cassette tape. This device would then have a hole in the top, to which I could attach a necklace chain via an intermediate metal jump ring. Straightforward enough, and a perfect application for 3D printing.
My first stop was to find an engineering drawing of the Compact Cassette format, designed by Phillips back in 1963. I could always measure the tapes in front of me, but for something like this, it’s generally easier and simpler to rely on the standard. Keying “compact cassette dimensions” into Google Image Search was enough to get me started.
I quickly whipped up a design that would hold both cassette reels in place. It relied on a pair of locating bosses mounted on a simple backing plate. The bosses would insert into the cassette’s reels, locking them in place. This would prevent the tape unwinding itself while being worn as a necklace. The backing plate had a hole on top for attaching a chain. A jump ring would be used, as is typical in pendant-type necklaces, to allow the cassette to lay flat upon the chest without twisting the chain. To create the necklace, one would simply need to insert the locating bosses through the tape. Then, the two 3D-printed caps could be attached from the other side with a pair of screws.
I ran a few test prints to figure out the dimensions. My initial attempts didn’t get the boss size right. This let the cassette reels turn freely. After a few redesigns and reprints, I got things nicely fettled. Much to my surprise, my third or fourth attempt actually ended up working as a snap fit. Thus, there would be no need to use screws and caps to hold the device to the cassette. Instead, the bosses could be snapped into the tape reels with a little pressure. With this method, the necklace adapter managed to hang on to the cassette quite well!
I assembled a series of necklaces and gave them a little product testing. By and large, the concept worked. The only issue was that boisterous activity would cause the jump rings to fail. This was largely due to the fact that the jump rings were intended for fastening small, lightweight pendants to a chain. A cassette tape, by comparison, was far too heavy.
I eventually realised a simple redesign would solve this problem. I eliminated the fussy jump ring entirely. Instead, I simply included a perpendicular hole for the chain as part of the necklace adapter itself. This does complicate the 3D printing process slighly, in that it may require some support material. However, removing that material is only a minor complication. The new design is much tougher, as a bonus. The integrated chain hole means that the cassette is far less likely to fall off the chain when the wearer is running and jumping around.
I have uploaded the designs to Thingiverse for anyone that wishes to print their own. It bears noting that snap fits are a finicky, precise thing. You may need to finesse the design slightly to get it to properly fit when printed on your own hardware. The print itself is fairly basic, and shouldn’t pose any issues on even the simplest equipment. I used ABS, but any rigid plastic should perform ably in this role.
As Compact Cassettes are a standard design, the adapter can be used with most any cassette you appreciate. I myself have a penchant for the brightest and most colorful designs. Of course, if your cassette is very precious or rare, perhaps don’t go fitting it with this adapter. Damage is unlikely, but not impossible. Overall though, it’s a fun way to show off your music collection. Plus, there’s something inherently cool about being able to pop a tape off your necklace and pump some tunes!