I mainly use a small socket wrench with an extender and thin-walled sockets. That covers 99% of all truss rod adjustments.
You're right.... that seems to covers the majority of them. But I've had a recent "run" of a couple of Yamaha basses (though it's happened with others) where the normal thin-walled socket and extensions don't cut it, depending on how the nut sits at any given adjustment.
I'm probably not explaining the problem very well. Let me try this.....
You might do well to cut the handle off and drill some holes. Think I might try that myself - thanks for the suggestion!
I chucked a thin-wall socket into the drill press and discovered ...man, those sockets are made from mighty hard steel! Try as I might (center-punching and all) I could not get the drill to cease it's wandering ways.
So I'll regroup, change up some speeds and try this again.... but it's a great do-it-yourself idea and we're not done yet!
Geez, this sequester-in-place stuff seems to be leaving me with too much time to think!
So, while trying not to put tooooo fine of a point on this whole topic, I've re-worked the idea and came up with something that (while likely best left to the manufacturing community) might be an even more workable idea.
OK, I'll leave the subject alone now! Back to the sorting of my stock of nuts & saddles!
I was thinking to drill holes in a standard cheap truss rod wrench - those are not so tough.
Good thought and I'll try it. Hey wait... aren't you supposed-to be out doing something fun today?!