A yo-yo is a toy with two symmetrical sides and an axle in the middle connecting those sides. There is a string attached to the axle and depending on how it is attached it allows the yo-yo to travel down and back up the string or to sleep when it reaches the end of the string. There are a few types of yo-yos out there that you’ll encounter throughout your journey to becoming a master yo-yoer. The first of which is a fixed axle yo-yo; the second is a transaxle yo-yo with; the third and most common shape is the butterfly shape with a ball-bearing transaxle.
Wooden Fixed Axle Yo-Yo
The fixed axle yo-yo is by far the most simple design; it consists of two halves (or hubs) and an axle connecting those two hubs. The yo-yo has a string that has been folded in half and twisted tightly to hold it in its screw-like shape. The yo-yo’s axle sits in the very end of this twist, where the string was folded in half. This way the tension in the string wraps the string around the axle, keeping it on the yo-yo, but also allowing the yo-yo to sleep since the string is not actually tied onto the axle like some of the first yo-yos were. Most yo-yos of this variety are made of two hubs pressed together on an axle, a simple three part toy. However modern versions of the fixed axle yo-yo are a little more complex, often involving a solid, non-spinning, wooden ‘transaxle’ that sits on a threaded axle which the hubs of the yo-yo are then tightened town around by use of the threaded axle and a nut, both sunk into the hubs to allow the tightening.
The second type of yo-yo is a transaxle yo-yo; it holds a very similar design to the modern fixed axle yo-yo in that it has a separate sleeve around the axle that the string is attached to. The axle in this model of yo-yo is typically smooth and often lubricated. The sleeve or transaxle typically had a groove in it where the string is supposed to sit (typically double wrapped around the axle). This groove keeps the string from slipping between the transaxle and the wall of the yo-yo, causing the yo-yo to seize up, typically making the incapable of sleeping. The transaxle yo-yo also incorporates the now important response system. A response system is the method by which the string in the yo-yo is bound up, allowing it to return to your hand when you tug on the yo-yo. Typical response systems for the transaxle yo-yo are a design called a starburst. A starburst design on a yo-yo is a pattern of raised areas emanated out from where the axle (or transaxle) is seated in the yo-yo. Though some fixed axle yo-yo’s use this technology they often don’t require it, as the tension in the string alone typically allows those yo-yos to return. When dealing with transaxle yo-yos however, the string tension often has nothing to do with the yo-yo’s ability to return when tugged up simply due in part to the fact that the string isn’t attached to the main axle of the yo-yo, but a sleeve around the main axle, so the tension in the string that could have been used to make it return by providing surface friction is lost to the transaxle.
Ball Bearing Yo-Yo
The third and final type of yo-yo you’ll encounter is called the ball-bearing transaxle yo-yo. It incorporates everything from the previous two up until this point except that instead of a simple sleeve around the axle of the yo-yo, you now have a ball bearing seated in the transaxle’s place. The ball bearing transaxle severely reduces friction in the yo-yo, allowing it to sleep for what was before unimaginable times. However with the reduced friction you start to need more and more effective response systems to make the yo-yo return. Some manufactures keep to the starburst design, but close the gap of the yo-yo significantly, without doing so the string wouldn’t effectively touch the starbursts and the yo-yo wouldn’t return. More commonly with these ball bearing yo-yos you see manufacturers using a rubber sticker that sits around the bearing on the inner wall of one of the hubs, this sticker degrades with use (so it eventually must be replaced) but is a very effective way of making the yo-yo return to your hand. A recent trend in response system technology has been to use a rubber o-ring as the response system, this is done by making a groove into the inner wall of the yo-yo around the bearing, similar to the sticker, the o-ring is then pressed into the groove and is a very effective and a longer lasting alternative to the sticker pad technology.