Very cool, Robert. Can you elaborate on how you got all the strings tensioned simultaneously before plugging the holes?
Sorry I have been a while responding to this but I have recently had cataract surgery and until I get my new specks I am bit handicaped.
Anyway, I thought about how I would get all the 5 threads tight at the same time and came up with the solution of placing two pillars between each of the frames and clamping them to the work bench. I had threaded a long piece of thread through the lower holes with a knot to prevent them pulling through. I then threaded them through the top holes and over the side where I fixed a weight to tension them up. It sounded great in theory and looked good as I put glue into the counter bored holes to fix the threads. Four of them held well but one of the corner ones slipped a bit much to my disappointment.
With the glue now in all the counter bores I was reluctant to dig it all out. I tried to tension the loose one by placing the sharpened end of a tooth pic with some glue on to see if it would encourage the thread to go further into the hole, and it did. JOB DONE. The thread is 0.4mm (about 10 thou) and the hole is 1.6mm. Unfortunately, I didn't take any photos of this operation.
Another tricky part then was to cut off the protruding tooth pic flush with the frame and hard up to the thread without damaging the thread. This was done extremely slowly and carefully with a fine saw.
