Tuesday, May 2, 2017

Gretsch Guitar Ukulele Repair

 April must have been ukulele month.  I worked on no less than four of them, in varying sizes, styles and colors.  This is an interesting concept - it's a Gretsch G9126 ACE  guitar ukulele. It couples the 17" tenor uke scale with the comfort and convenience of six strings (tuned like a guitar capo'd at the 5th fret, A to A.)  Neat!

The bridge has been giving me some problems.  I noticed it last summer when I did some electronic work, and this time I couldn't let it go without making it better.  It uses the slightly archaic system of angled slots cut through diagonally from the top to the back of the bridge:

In this case the slots are augmented with holes intended to receive the knotted ends of string. Only problem is, the slots are a little wide and the holes are a little deep.  The knots on the 4th and 5th strings want to creep up inside the slot and once lodged it's a real struggle to get them out.

 I'm going to inlay a strip of wood along the back edge to eliminate the problem.  I see a couple of suspicious looking circles that give me the creeps. I can't be sure of course, but I think there might just be some steel screws hiding in there.  I should probably stay away from them with the router bit...

 The top on the instrument is not flat.  Whether by design or the influence of static forces, it's markedly concave. The braces are all secure though.
 For this job I'll use the plywood platform I concocted to let me rout saddle slots in bridges still glued in place on the guitar. This comes in handy for repair work in instances where the saddle isn't compensated correctly. Here it will function as a useful guide.  I protect the top of the instrument with padding.
 It's clamped to the body with arched beams and cork padding.  The 10' radius is tighter than most guitar backs, so the pressure gets applied only on the outside edges where the lining and side offer good support.
The track is a snug fit for my palm router and can be angled or moved back and forth into position. I set the bit for the final depth and pivot it in, taking a series of passes.

There we go: a nice straight-sided cut. I will square up the corners with a chisel.
Planing a piece of rosewood to fit.
 Once inlaid and glued, I'm ready to drill the string holes. This operation takes a little courage!
I carefully plotted the required angle by measuring the bridge and figuring out where the drill bit needs to emerge, then planed a little triangular block to act as a drill guide.  I apply masking tape to its underside, and also the top of the bridge.  Superglue holds the guide in place while I drill.
I protect the top with a piece of thin sheet steel. Holding the 1/16" drill bit in line with the string slot I carefully kept downward pressure on the block. The strings all emerged in a reasonably straight line and in their correct spacing.
 All set.  Almost.  I went back and refined the saddle because it struck me as bulbous and uncouth as furnished by the factory. I can think of more elegant ways to tie the strings on too, but I knew I would likely have to take them off a few times while working on another repair issue (a buzz that took a long time to track down), so I just tied some knots. It works.
These days I seem to be uploading more repair videos on YouTube than writing about them.  If you're interested you can find them here: https://www.youtube.com/user/twoodfrd

1 comment:

  1. Technology does have some complexities associated with it. Be it be old or new technology, it has some glitches and flaws associated with it. We at Trend Micro Geek Squad, are a team of technical expert professionals, offer support related to any of your digital or electronic device failures. Whenever you get an error, your system is running slow, or not working adequately call us straight away.
    Our Geek Squad Tech Support team is focused on tuning-up your devices and bringing them in workable condition as before.Webroot Geek Squad support related services include providing a quick security solution to resolve the issues that are said to be contagious.