I am receiving quite a few inquiries from people with Steinberger string locks that want to use double ball-ended strings. To date, I have turned them down since the string has to be threaded through the tuner and the single ball acts as a stop.
But as I had been working on a custom string fastener for Italian luthier Michele Benincasa (see future post) I got to think in some new ways. I realized that by very small modifications to my current tuner, I could indeed support double ball-ended strings. And, by no small coincidence, the length of the tuner housing is very close to that of a Steinberger R-Trem, which means that the string length will be just right. The pictures below show work in progress and are not finished.

The string lock. Michele wants to use six of these mounted behind a tune-o-matic bridge instead of a regular tailpiece. He does not want to run the strings through the body of the guitar, which is the reason for this design. However, these will work equally well at the head of the guitar! I do not have to rely on a Steinberger headpiece, but can continue to offer per-string pricing and packaging.

Here, you see the ball end of the string seated in the lock.

The modification to the tuner housing. I have drilled a hole and routed a slot.

A modified plunger. This will continue to work as usual with strings threaded through it, but also in this manner.

The action will be more than enough, since it can actually run through the knob. I will make a few more of these prototypes and send off for finishing in the near future, so stay posted.