Some of you might have noticed me mentioning "Tuner Backlash" in some of my previous thread posts, and I thought I would explain what Tuner Backlash, or Tuning Machinehead Backlash is in this thread, so, what is Tuner Backlash?
Tuner Backlash is the amount of play in a Tuning Machinehead where the Tuner capstan doesn't rotate as you're turning the knob, what happens is this, you rotate the tuner knob to bring a string up to pitch but nothing happens till you reach a certain point, then the Tuner capstan starts rotating and increases the tension on the string, when you rotate the tuner knob in the other direction to lower the string pitch the same thing happens, this combines with any friction in the nut slots to make tuning a guitar accurately to pitch difficult, it can also make keeping the guitar in tune hard too as the string-tension either side of the nut tries to equalize, you might have noticed this on a guitar with worn out tuners that have difficulty holding pitch.
When Tuning Machinehead manufacturers design Tuners one of the goals is to reduce Tuner Backlash as much as possible to increase tuning accuracy, some designs, like the Stenberger designed Gearless Tuners eliminate Tuner Backlash by alot, I've found that the Gearless Tuners have the least amount of Tuner Backlash out of all the sets of Tuners I have ever bought.
Sometimes Tuner Backlash can be caused by excessive wear on the internal gear system, sometimes it is caused by a loose-fitting Tuner knob, sometimes it's simply caused by manufacturing defects, or poor quality manufacturing in general.
I've bought a few sets of Tuners from some well known manufacturers and brand new, right out of the box, within each set there were a few Tuners with significant Tuner Backlash, most of the sets were of the more modern sealed and permanently lubricated types.
