Adjusting and Repairing my Royal Trifonium Ticone Guitar

I’ve been putting off adjusting the action on my wood bodied tricone resonator guitar. The action has been on the high side of acceptable since I purchased the Royal guitar from Imperial Guitars. Then, last week, an internal post came loose after changing the tuning. I couldn’t have the post rattling around in the body nor did I want to leave the cones without support. Time to adjust and fix the guitar

Loosen truss rod for more relief—tighten for less relief.

The first step was to adjust the relief. My eyesight has gotten worse (macular degeneration in the right eye doesn’t help) but I used a trick I learned somewhere to set the relief. The object is to adjust the truss rod until you can just hear the string tapping the 7th fret when you press down (and hold the string down at the 1st and 12th frets). There was definitely too much relief before I made the adjustment.

Relief at 7th fret: Capo at 1st fret and I’m holding string down at 12th fret.

Once I adjusted the relief, I measured the action at the 1st and 12th frets. I had my wife double and triple check the measurements because of my eyesight.

  • The action at the 1st fret for the 1st string was the same as the 6th string: 1/32nd inches.
  • The action at the 12th fret for the 6th string was about 3.5/32 inches or 0.110 inches.
  • The action for the 1st string, 12th fret was 0.90 inches which is about 5.8/64th inches.

National adjusts their resonator guitars to 1/32nd inch on both low and high side of 1st fret. The 12th fret action is set to just under 3/32nds of an inch at the 1st string and just over 3/32nds for the 6th string. This is slightly higher than typical for an acoustic guitar but still within the normal range. It also facilitates playing bottleneck slide. More importantly, it’s fairly close to my tricone’s measurements. I’ll leave the action as is.

Fixing the unglued sound post

This is the scary part. I have to open up my resonator to get to the post that is bouncing around inside the body. The first step was to loosen the strings. I used a trick I saw in a youtube repair video. I taped the strings at the tailpiece so they wouldn’t become unattached when I removed the endpin, tailpiece, and resonator cover. It makes putting things back together so much easier.

Taped strings to tailpiece before removing end pin and tailpiece.
Looking in before removing a cone.

I only removed one cone to retrieve the rogue wooden support post. A picture of the post is below.

The post, outside the body.

I could see where glue had been applied for the post when I looked into the body. I used a small amount of Elmer’s Carpenter glue, dabbed where the post had been, then slid the post back into its original position.

Glue marks indicate where I need to re-glue the post.

I reassembled everything, turned the guitar back to an Open D tuning and played. The guitar plays better than before.

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