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Installing Stewart MacDonald's
Five Star Planet Pegs
© Frank Ford, 7/18/02; Photos by FF

This 1925 Gibson Mastertone tenor banjo has its original Grover tuning pegs. I've always considered these some of the most disappointing banjo pegs ever made. With their 2:1 gear ratio, they deliver the promise of a geared tuner, but not the performance, because the low ratio tends to make it difficult to tune and hard to keep the buttons tight enough to avoid slipping. On top of that, they mount with two large "ears" and screws in the back of the peghead.
On the left, we have today's best replica of yesterday's (1920s) best pegs, the famous "Planet" pegs. Trim and neat as the originals, they even have the little Saturn logo stamped on the casing. The only problem with Stewart MacDonald's version is that they come with these chintzy fake-o mother of pearl buttons. The good news is that we can transplant the old tuner buttons. . .
First, I'll unscrew the old pegs from the back side.
Taking the biggest Phillips screwdriver I can stick in through the tightly fitted bushings, I wiggle them around and around gently until they just crawl up out of their holes. That way, I avoid chipping the brittle dyed maple peghead veneer as I might if I tap the bushings out from the back side.

I use a tapered violin peg reamer to enlarge the holes to fit the new pegs, which have a nominal shaft diameter of 3/8." In fact, it usually helps to make the hole a tiny bit bigger, so the pegs will slip in easily. My reamer has a final diameter of 10 millimeters, so it works perfectly if I just ream the hole all the way through. Using a hand reamer like this, I can work slowly and safely to enlarge the holes, with no danger of splitting or chipping!

Unfortunately, the buttons have different holes in them.
And, of course, the shafts match the holes.
Taking the trim cap off the back end of the Five Star Planet, I reveal the length of the shaft that needs a bit of modification to fit the old buttons.
It's really quick and easy to file the shaft to a square shape that allows the old pegs to slip right on.
Just a few strokes with a coarse file on each side, a bit of trial fitting, and the job is done.

Here's a cool little feature you don't see on modern banjo pegs. Very little indeed, it's a thrust washer to protect the ivoroid from the screw as it bears down to tighten the button. If modern makers used these little washers, they'd have to raise the price of the tuners by, oh good heavens, about a penny!

To keep the peg from rotating in its hole, there's a tiny little stud sticking up into the back of the peghead.
This neck is made of hard maple, so I'll predrill little holes for the studs. I'll orient the peg the way I like, which usually means having the little stud pointing down toward the neck. It's arbitrary, but it pays to have all four the same so the logo faces the same way on all four.
A light tap with my plastic hammer gives me just the little dimple I need to start my drill.

I use a 1/16" drill and go in about 1/8," the full depth of the stud. On a neck made of a soft wood such as mahogany, I could eliminate drilling the hole because the stud would make its own very easily as I install the peg.

As I tighten the installation nut from above, the peg draws up tightly and neatly against the peghead.

Now I can restring the banjo in comfort and style, tightening the button against the 4:1 planetary gear system until I have smooth and accurate tuning. As you can see, I didn't complete the job by touching up the holes on the back of the peghead. What you can't see is that there is virtually no finish left on the back of the neck, so the owner of the banjo thought the holes wouldn't stand out as looking ugly. That little statement of condition will also, I hope, serve to placate those vintage banjo buffs who think all instruments should be left totally "original."

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