Maintaining Your 3D-Printed Yoyo

3D-printed yoyos are different from traditional metal and plastic yoyos in a few critical ways which make for important differences in how you need to care for each kind of yoyo. In this article, I will describe these differences and teach you all you need to know about how to keep your 3D-printed yoyos playing great in the long run.

If you'd like to try the state-of-the-art in 3D printed modern yoyos, consider the Drop, available here.

If you are under 18, do not attempt to maintain your yoyo per this article. Get an adult and have them help you. If you have any questions you may always contact me at ross@modernyoyos.com

But first a little theory and 3D-printed yoyo anatomy

To ensure that any yoyo plays "smooth", without excessive vibration every part of the yoyo must be "coaxial". This means that the central axis (the imaginary line running through the center of a round object) of the yoyo body, the pads, the bearing, and the axle all need to line up perfectly. To achieve this, 3D-printed yoyos have what's called a "bearing spacer" which screws onto the axle until it's flush with the yoyo body, and then the bearing is placed over this spacer (the spacer is the green piece in the center of the bearing in the photo below). So when you unscrew your yoyo and find this piece inside the bearing, don't worry, it's supposed to be there.

Removing the bearing on a 3D-printed yoyo

Because of the bearing spacer, you can't fit a normal bearing removal tool inside of the central bore of the bearing like you normally can with a metal yoyo. To get around this, you will need to cheat by gripping the bearing from the outside. However, you may notice that on some yoyos, the bearing is too hard to remove with just your fingers. So, and I do not recommend this for metal yoyos, you may need to use a pair of pliers to carefully grip the outside of the bearing for removal. This is done by applying as little force as you can to get a solid grip, and then wiggling the bearing loose while pulling away from the yoyo body.

Don't over-tighten the yoyo during assembly

Fully 3D-printed yoyos are intrinsically delicate because the material they're made from is not very strong compared to aluminum. If you over-tighten the yoyo during assembly, you can cause the material to compress to the point that the material starts to fail. Tighten it until it's snug, but don't force it.

If the bearing spacer protrudes past the bearing, do not assemble it!

Here's what the yoyo should look like normally:

And here's what it looks like when the bearing spacer protrudes past the bearing:

The bearing spacer is not held in place by anything, so sometimes it manages to get loose while unscrewing the yoyo. When this happens it can result in the spacer protruding past the bearing. If this happens, do not assemble the yoyo until you've removed the bearing from the spacer, screwed the spacer back into place (flush against the yoyo body) and then replaced the bearing. If you screw the halves together with the bearing spacer protruding, you may end up stressing the spacer or the yoyo body to the point of permanent damage. Note that if the spacer is screwed in completely and there is a very small amount of protrusion, around the thickness of a piece of paper, this is normal.

Never swap to a "responsive bearing"

A "responsive" half bearing is a bearing that is half the width of a standard bearing. In metal yoyos, these can sometimes be swapped in place of a standard bearing to reduce the gap width and make the yoyo respond more easily. With a 3D-printed yoyo, however, the half-size bearing just leaves half of the bearing spacer protruding past the bearing. See the last paragraph for why you should not assemble the yoyo in that state.

Heat considerations

3D-printed yoyos that are made with a Fused Deposition Modeling  (FDM) process always use plastics that are highly reactive to heat. This is an important part of how the FDM printing process works. Plastic is heated and then extruded into the shape of the final part. This means that 3D-printed yoyos can be affected by excessive heat. Under most conditions, this will not be an issue, but it's something to be aware of if you're considering leaving your yoyo on the dash of a hot car or forgetting to remove it from your pocket before putting your pants in the dryer.

Cleaning the bearing after breaking in

In 3D-printed yoyos, steel comes in contact with weak plastic, and while the yoyo breaks in, this can create tiny pieces of plastic that can get into your bearing. If your yoyo becomes responsive or loud, simply have an adult clean it in a jar of 100% acetone (nail polish remover with no additives) before adding a drop of your favorite thin yoyo-bearing lubricant.

Layer Lines and Durability

Yoyoers are accustomed to plastic yoyos being extremely durable, and 3D printed yoyos can certainly take a hard ding. The issue is not a matter of one ding but many over time. When printing a yoyo, over 200 layers of plastic are laid down, and the interface between each one of those layers represents a weak point. When you ding the yoyo, especially on concrete, cracks may begin to form between the layers, and in time these cracks can grow and result in a broken yoyo. This is why I recommend 3D-printed yoyos as "studio yoyos", that is a yoyo that is used for practicing indoors for filming rather than one that you carry around as a beater. I always recommend resilient 7075 or 7068 Aluminum yoyos such as the Dopamine as daily carry yoyos.

"Sharp spots"

The 3D-printing process can sometimes leave small bumps on the flat face of the yoyo. The extruder starts laying down plastic for that layer in these spots. These spots are removed from the yoyos sold on modernyoyos.com, and each yoyo is tested for sharp spots. However, if you are printing your own yoyos or you find an imperfection that was missed during testing, an adult can easily remove it with a small pocket knife (kitchen knives are too flexible and unwieldy). Just trim it off as if you are whittling. You can also use a fine sandpaper, however, this can create a micro-abrasive finish that "grips" the string.

If you'd like to try the state-of-the-art in 3D printed modern yoyos, consider the Drop, available here.