| Youth wants to know...
Which way are mandolin gears supposed to turn? 
At some point someone finally realized that gears functioned better
if the worm was above the cog. Why? Gears always have a bit of backlash.
With the cog above the worm, that slop was pulled tight by the string tension.
With the cog below the worm, the string tension did nothing to absorb the
slop or backlash, and staying in tune was more difficult.
Sometime around 1925, everyone in the industry agreed to change to the
other configuration, and gears started to be made that way. For guitars
and simple mandolins, it was no big deal: just move the post holes so the
buttons lined up along the sides of the headstock correctly. But on Gibson's
F-style mandolins, it really messed with the aesthetics of their headstock.
The gear shafts with the worm attached had to stick out just so, and moving
the gear posts down the face of the headstock looked weird. So being slaves
to fashion, they didn't change them.
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| Except some folks have managed to redesign the Gibson headstock to
work with the new kind of gears. But the new tuners really don't work with
the old headstock. Have a look:
As you can see here, the top treble-side replacement tuners hit the curlicue. If you move the whole gear plate down, the posts lie very oddly on the headstock as seen from the front, which means the posts closest to the nut have to be moved way down and the plate is projecting off the back of the headstock. The proportions of the headstock are seriously tweaked, if not shot.
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The bass-side tuner posts in the left image are photoshopped to where they'd be with the modern tuners. The treble side is unchanged. The image on right shows a headstock with modern gears. |
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Gotoh makes their F-gears both ways. Stew-Mac offers only one of them, the early style:
Gotoh makes them with the worm above and below the cog in a variety of styles. From eBay and elsewhere:
From Roger Siminoff's webpage:
Note the different shaft lengths on the above gears.
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| Here's the issue: |
If the plates are aligned, the posts and button shafts are therefor different. The post location is important, and so is the shaft location.
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If the posts are in the same location, the plates and button shafts
both come out different, as in the photo of the F-5, above. This is also
not workable unless the headstock is entirely redesigned to accommodate
it..
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In any case...no matter which type of tuners you have, the buttons should turn the same direction to make the gears turn the right way, like this:
Turn that D button counterclockwise, and it should make the post do the same thing whether the worm is above or below the cog. Once again: No matter which type of gears is on the mandolin,
Let's abandon the term "reversed" with these gears. Nothing is reversed.
(Or, like some
Eastman gears, they are simply mis-engineered.) You cannot take gears apart and swap parts to make them turn the opposite way. Some observations about a couple of Gotoh gears on the market right now |
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