In my search for cheap alternatives, I discovered Guyker brand locking tuners on eBay. At ~$40 for a set of 6 in-line, I read some reviews around the net and thought, you know these might just do the trick.
I was wrong!
Absolutely the worst thing I've ever put on a guitar. Even standard non-locking tuners from any standard kit would be 100 times better. Here are some of the issues I had:
- High E and B did not want to lock, and had to be wound around the post like standard tuners.
- The set I bought had two registration posts instead of screws, so you end up with these ugly holes in the back of your headstock.
- There was an incredible amount of play in the gearing, meaning you had to complete almost a full turn before the gears would engage when reversing direction. Super annoying when you're going back/forth to perfect pitch.
- In general, the machining is terrible. The nuts wouldn't run smoothly down the posts, so when you're tightening them down from the front they would occasionally catch and spin the machine head, dragging the registration posts and leaving ugly arc shaped dents across the back of the headstock.
- The registration posts combined with the terrible nut machining made it almost impossibly to get them to line up neatly.
- The locking mechanism clamped with more of a cutting motion rather than "clamping", meaning strings were prone to breaking at the post.
These things are an absolute waste of time and money. Get any reputable standard non-locking tuner for the same price point and enjoy a better outcome, or spring for a decent set of locking tuners instead.