High Quality Friction Tuners to fit 7mm peg hole?

[MJB]

Better picture.

IZheadstock.jpg

[Web_Parrot]

With regard to using a tapered reamer, I'll 'testify' to using one on 10+ occasions to enlarge headstock holes. I purchased mine for about $9 from Harbor Freight, choosing one with the least taper-angle. FWIW, just about any taper angle will work providing you are really really patient, and use the following technique.

Because headstocks are (relatively) thin using an alternating side to side approach protects you from ending up with a hole that is significantly narrower on one side than the other.

So I :
1-measure the diameter of the part that will eventually be inserted into the hole. You can use a set of calipers for a certain amount of precision, or an adjustable spanner ( an adjustable 'crescent' wrench). Transfer that measurement to the reamer, marking it with a pencil.
2-Place a piece of tape (painters tape, electrical tape) about a half-millimeter below the pencil line (i.e., to make a hole slightly smaller than what would be made to the pencil mark)
3-Slowly begin using the taper, making two or three rotations on the front side, then switching to the back side using the same number of rotations.
4- when you start getting close to the tape, try dry fitting the tuner.
5-Now limit rotations to one full turn for front then back. After each rotation, check the “fit” of the tuner.

You’ll find that once the tuner starts to just fit inside the hole, the fit near the center will be slightly snug. At this point I’ll take a few more gentle passes from the back of the headstock until the tuner slides snugly from the face.

[kissing]

Why do you have the third string wound toward the outside instead of toward the center of the headstock? I've seen this on first and fourth strings but never on second and third strings. All my ukes have all 4 strings wound wound toward the center as are most I've seen.

To be honest I hadn't given it much thought; other than having all the tuners turn clockwise to tighten.

[kissing]

To give an update!

The $33 reamer worked beautifully! Perfectly enlarged my 7mm holes into 8mm holes.
Installed the premium Gotoh tuners, which I think look beautiful (tune very smoothly too!).

High end friction tuners are a joy to use.

If I ever want to install Gotoh geared UPT's in the future, I can use this reamer to enlarge the holes to 10mm.