Tuners not stubborn enough...

[grandmainger]

On one of my A strings, the tuner is a little bit too soft compared to the other string(s). I'd like to make it a little tighter so it's easier to tune.

Can I simply tighten the screw that's 'in' the cog?

[sunburst]

Can I simply tighten the screw that's 'in' the cog?
I don't know of any tuner that has an adjustment screw in the cog. It should be tight enough, but beyond that there is no gain in tension.
Waverlys are the only mandolin tuners that I know of that have any adjustment, and it's not a simple screw.

[grandmainger]

Thanks for that sunburst. I'll leave the screw alone.
Out of curiosity, what is the function of that screw on the cog? If it is just to hold the cog in place, would if not be easier to have a standard rivet-style system?

[John Flynn]

I have tightened those screws you mention with some success at adding tension. As sunburst rightly points out, they are not intended to be adjusting screws, but if you tighten them, especially on cheap tuners, you will often get more tension. Whether that will translate into your mando staying in tune better is another matter. It may or may not help.

[grandmainger]

OK, I might give it a shot.

The mando stays in tune all right actually, it's just a matter of me pushing the knob too strongly while I tune it which is annoying... I'd like all od them to have the same firmness.

[TommyK]

The screw's only function is to hold the cog to the tuner shaft. If it is loose, it won't engage the worm gear, properly. Sloppy engagement will cause a lag in the movement of the tuner shaft with relation to the tuning button as the slack is taken up. Some may perceive this as a looseness. So first order of business is to make sure the screws are all tight. If they are persistent in becoming loose, use a spot of elmer's glue as a thread locker. I like Elmer's white glue because on an instrument there isn't a lot of mechanical stress, it's easily removed when you want to and it's CHEAP!
Two of my guitars have the cheap 3-to-a-plate tuners. The plate is stamped metal with hooks on either side of the cog (pinion gear) which holds the worm gear. Out of the box none of the tuners 'feel' the same. By removing the pinion gear and tapping ever so lightly on the hooks I was able to get the feel I wanted up and down the head stock. This takes a light touch and some tap and fit and tap and fit to get the feel you want. No bigger than a 7 oz hammer. Yes real men do sometimes use 7 oz hammers. Tapping the hook toward the tuner shaft tightened the interface. Tapping away from the tuner shaft loosened the interface.
I know it's primative, but so are the tuners.
My other guitar has covered grover-esque tuners and they work smooth, smooth, smooth. I've never had to work on them.