Truss rod problem

[Christ Kacoyannakis]

Put this in acoustic guitars, but it probably goes here.

I have two Greek bouzoukis that I made with Allied truss rods with the Allen head adjusters. On both of these instruments, the Allen head wrench opening has become stripped out. They are only four years old. I purchased the Stew Mac Gripper wrench with the tapered Allen head to try to adjust these instruments, but they are not working. I did carefully check the rods before installation. I don't think it is a problem with the adjustment of the truss rod itself not working, but is a problem with the adjuster head wrench opening being stripped. I thought these were touted by everybody as the "best" out there. The problem is there are 8 steel strings on a bouzouki, and playing the instrument involves a lot of very fast and intricate runs, so players like very very low action. As a result, the neck sometimes moves, and the player wants to constantly adjust the action to be as low as possible.

My questions are:
1. Is there anything to be done to fix this issue, other than tear off the fret board and pull out the truss rod, and
2. Would it be better to put in a rod with a hex nut, or slotted nut or spoke nut so that if it gets stripped it can be removed or is less likely to get stripped (a bouzouki neck is pretty narrow though, like a banjo (usually about 1 5/16th at the nut), so I like the Allen head adjusters since you don't have to remove more than a 1/4 inch channel for the rod and adjuster.

Any advice would be greatly appreciated. Thanks in advance everybody.

[David King]

I'm surprised no one answered this yet but here goes. Get a set of Torx drivers and grind the tip of the one that comes closest to fitting the allen key hole. I grind it flat while removing enough material so that you get a sharp 90º angle between the sides of the bit and it's end. You can then drive it into the stripped hole and get a grip usually. The process is called broaching in machinist lingo.
If you're too indisposed for a set of Torx drivers you can file the end of an allen wrench with a chainsaw file on the six flats to get the same thing.
I think the Blanchard rods from Allied use a 4mm key IIRC so you could start with an 11/64" or a 4.5mm key assuming either of those exist.

[Peter Wilcox]

I'm surprised no one answered this yet

He double posted it - discussed here: http://www.mimf.com/phpbb/viewtopic.php?f=3&t=3155 But your broach is cheaper.