Most metal yo-yos use a set screw axle. So how do you tune a yo-yo with a set screw axle? In this guide I’ll try to explain how to tune a yo-yo with a set screw axle. As a side note I’m going to go into mind numbing detail about all things. I just feel it would be best to answer all questions before they are asked.
The first thing you need to do is remove the axle of your yo-yo and find the side that has the hole for the hex key. If the hole for the hex key is facing out away from the yo-yo all you have to do is put the hex key in there and turn counter-clockwise, pretty simple. If the axle doesn’t have the hole for the hex key facing out; or if the axle doesn’t have a hex key (a metal zero) wrap the axle with a paper towel and use a pair of pliers.
Now wrap the end of the axle (the one that doesn’t have the hole for the hex key) with Teflon tape around five times. I say around because sometime you need more sometime less. Also it’s best to wrap the axle the opposite way it is threaded so the tape isn’t pulled off in the next step. The idea is to make the axle a very tight fit in the yo-yo. Alternately, you can put a drop or two of Loctite on the axle.
Now, screw the axle into the yo-yo by hand until it is finger tight. The axle won’t thread very far into the yo-yo since you wrapped it in Teflon tape or put Loctite on it. If you went the Loctite route, which I prefer, let the yo-yo sit as-is for about twelve hours.
Turn the axle a full turn. Put the yo-yo together. Throw it and touch your finger to it to remove any vibe caused by your throw. Is it smoother? If not then try turning the axle some more and testing it. Give it a half turn. Is it smoother now? If not, then try backing it out a quarter turn. How about now? Maybe go a quarter turn back in. Always test to see if the yo-yo is smoother after each turn of the axle. What you are doing is changing the alignment of the two halves relative to each other. Keep working with quarter turns until it gets smoother. Then try one eighth turns to find that butter zone that gives you a smooth yo-yo.