Basses built with a uke scale length of 21 inches.
This bass is a 21" scale, with a piezo saddle mounted in an adjustable bridge. The soundhole is just for looks. The strings are metal-wound Kalas. The fretboard is cut out of the ugliest piece of wood I ever received. For such a small neck, I managed to cut around most of the ugly, and the result isn't half bad.
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This is a spoke nut version, for use at the neck heel.
Here is a variation intended to adjust at the headstock rather than the heel, although it would work fine there too. I substituted a 1-1/2" 10-32 SS cap-head bolt for my usual spoke nut and threaded shaft. It is captured the same way, in a drilled-out coupling nut with a ground-down hex nut. The rod itself is 48" 3/16 rod steel, bent back on itself. Both coupling nuts are grooved on the attaching surface to hold the round rod. This greatly simplifies alignment and assembly, and the cap-head bolt eliminates one solder joint. All parts from my favorite luthiery supply shop, Home Depot.
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