Mossman Guitar trussrod tool

[Tony Lewis Skypilot Guitar Repair]

Hi Joseph. How much room between the brace and the heel block? 1/2″? What I’ve done in similar circumstance is to take your shaved/cut 12 point 1/4″ shallow 3/8″ socket (12 point sockets, as you probably know, start out thinner than their hexagonal counterparts and 1/4″ inch drive keeps them in a straight cylinder) and cut down to absolute minimum so you have just enough depth of 12 point to grab nut and be flush with tail block. Then weld/fasten a piece of thin flat stock steel to the socket and make it so that it just clears bottom and then ell’s out 90 degrees for leverage. 12 point sockets don’t need to be rotated as much as hexagonal so “throw” between twists is much less allowing for easier adjustment. I shave sockets to thin them by sticking in a drill press before cutting down and using a file. Can do same by setting a drill with 1/2″ chuck in a vise. Sorry if this is just redundant nonsense you’ve already thought of or that it won’t work in your situation.

[Thomas Snape Cold Stream]

I had a Mossman Great Plains in the shop this summer. I didn’t need to adjust the truss rod, but I noticed it would need a special tool to do so. I made a sketch in my notes of a tool I thought would work in case that guitar end up on my bench again. In my estimation, the 3/8″ socket would need to be cut down to 10-12mm long in order to be able to clear the brace and get it over the nut. Then I thought I would try drilling some transverse holes through the back end of the socket that would allow me to turn it with a piece of rod.

[Thomas Snape Cold Stream]

I went ahead and modelled it to make sure it looked reasonable. Started with a 3/8″ socket CAD model from McMaster-Carr. Handle is 1/8″ rod.

[Tony Lewis Skypilot Guitar Repair]

Ya! That’ll work…..I might weld the rod in. That’s the beauty of the 12 point. Don’t have to turn much to re-engage.