Sperzel Locking Tuner problem

[buy14u]

The high e tuner on my parker NightFly will tune the string almost to a d pitch, then I hear a slight pop, and the string goes slack.  I've tried multiple times with the same result.  I checked to make sure the string was tight in the tuner and it is.  Any thoughts, or is the tuner shot?
Thanks for your help!

[sybersitizen]

Are you sure it's the tuner letting go? Or is it the string partially unwinding at the other end? Lots of people report the latter, and it has happened to me. If so, wrapping the string through the barrel end beforehand can prevent that.

[billy]

Agree, the ball end unraveling is more likely here. Some guys solder them but running the free end once through the hole in the ball end should do it. FWIW I only had an issue with d’addarios doing this.

[JamieCrain]

+1.
Daddarios also caused me problems on the e string on my Nitefly. Changed to Ernie Ball, all good.

[Big Swifty]

Yeah, what is it with D'Addarios and that high E?

Havn't had it happen for quite a while though..

If it's not the string itself, then the internals of the tuner have some problem, a stripped cog/thread/whatever it's called, or partially worn so as it only slips when it comes under tension.

Or maybe the pin itself is worn at the end and not fully locking properly

Try tightening (a bit) the screw on the top of the tuner button, see if that helps, otherwise...

You could try unscrewing the back/locking thumbscrew completely, see what's going on in there, but pretty sure that'll wreck the threads, make it kinda bodgy from here on in..make sure you can get your hands on a replacement before going down this road!

Cheers

B.S.

[billy]

Crazy physics I think.  Something about the winding method and string diameter, along with torque initiated from stretching and then combined with the geometry of the hole. 

Had it happen on JB's mojo last night...