"Kit" can mean a lot of things. For example, an fine instrument plus case plus a ukulele pick, a 3 inch "noter" plus a CD and book can be described as a kit. A kit can also be just plans and pieces of wood.

Particularly if buying through eBay, ShopGoodwill, or a crafts store any document, description or label should be treated as mere suggestions about possible origin. Often accessories and documents found in the same closet with an instrument are all simply thrown into one box.

That's not to criticize auction purchases, that's how I got several of mine.  

On my instruments I typically use a nut or bridge with a flat bottom and a sloped (not rounded) top with the high edge toward the fretted portion. I then carefully slope the slots to match. The VSL should run from the inside of one to the inside of the other.

If you have not studied the Folkcraft website, a visit is in order. https://folkcraft.com/

Connecticut should only indicate that this was made when the factory was there between 1979 and 2006. I don't see anything on the Folkcraft site that indicates that they made "noter style" instruments. Almost any Appalachian dulcimer can be played with either a noter or the fingers.

Since the builder of a kit can glue any label inside, there is no reason to expect to see "made from a kit" inside. A label is simply a label. 

Did you, by any chance, flip the bridge over while changing strings?

As shown in the photos, the nut is well off center. The string grooves appear to be rather tight on the strings, but it is hard to tell from the photo. Perhaps the cut-away for the outer two strings isn't as big as it should be and is creating sideways pull.

You should check string heights when you acquire a "new" instrument. There is lots of good information on how to do that here on FOTMD.

Folkcraft sells a variety of replacement bridges complete with notches.
https://folkcraft.com/pages/search-results-page?q=bridge&page=1&rb_product_type=Building%20Supplies%20%26%20Plans

I don't use tuning apps, I use clip-on tuners of various makes and models.

For a dulcimer, you want/need one with a CHROMATIC setting. Some have settings for guitar, fiddle, ukulele, etc. and in that case you need to be sure that you are using the C setting. It's usually a very small letter and easy to miss until you understand its importance.

That same thing applies with an app. I' not aware that Fender ever made dulcimers, and I wouldn't be surprised if their all only had guitar settings

Rule #1 for purchasing a dulcimer: If possible, PLAY IT.

Dulcimers come in a variety of shapes and sizes, and you need one which fits YOU. Even if you can barely play, putting it on your lap will help you decide whether it fits you.

Don't worry if you can't put it in proper tune, if one string will play you can get a pretty good sense of the tone which the body shape and size provides, and you can check for things like buzzing. Fingering each fret in order can be used to check for a warped stick or high frets. If your ear is decent, you can use Fret 7 (the octave) to roughly check fretting, nut, and bridge problems.

Generally any McSpadden, or other big name instrument, made within the past 20 years is likely to be OK if there is no visible damage, although a good look at tuners, etc. is good advice.

There are no really good price guides for used instruments except eBay and Reverb asking prices. If you can't play it, always check shipping charges, etc. since these are sometimes more than the instrument price.

Don't worry if you don't understand all this, but see if you and the instrument are a comfortable and pleasing match. You should be looking for a "lifetime companion," not a "trophy spouse." You may need more than one date, don't rush it.

You can make a stable, playable dulcimer which is only a stick. You just won't hear much without adding a sound box or putting it on a table top resonator.

The cardboard dulcimers are a good example. The structure is usually a piece of 1x2 lumber with a modest strum-hole. Once tuned and settled in, the cardboard dulcimers will often hold relative tuning for months when stored in a cloth bag, and only need a touch-up when string tension is affected by room temperature changes.

I'm not a fan of hollowed out fret boards, etc. I'm not convinced they can be proven to make better music. When I build, I like the basic stick and box construction. I think pear and hour glass box shapes, fancy woods, lots of sound holes, etc.are mostly decorative.Box size does definitely affect the sound produced.

Decoration is fine, but should be seen as such. I put ebony or mother-of-pearl dots on my simple sticks and prefer trapezoidal boxes with shaped holes to rectangles with round holes. Sometimes I paint folkish designs on the boxes.

I can appreciate fancy dulcimers just as I can appreciate an Aston-Martin car - but I drive a basic small car and enjoy playing "cheap" instruments.

I taught engineering mechanics (Statics, Dynamics, and Strength of Materials - the courses which drove students out of Engineering) for a quarter of a century. My view is based on a lot of 'book larnin.' Over the years some of us develop structural intuition just as musical intuition grows for some and not others.

My remarks are focused on "true dulcimers" with 3 or 4 strings and a stick which runs the full length of the VSL. The body is relatively narrow and the tension of the strings is modest. The sides, front, and back are sort of a stiff tube. The tension causes the body and fret board to curve very, very slightly and the wood to "creep" slightly over a period of days and "settle in."

An acoustic guitar body has only modest amounts of bracing inside, and the heavy wound steel core strings create a much larger tensile force. Solid body guitars are very different structurally.

A fiddle body is actually a complex shell shape, and the string tensions are rather low. On many fiddles the strings have a gut or nylon core.

On a modern instrument of these families the body might actually be graphite reinforced plastic. Tension will still cause minuscule bowing of the body, but there will be no creep.

There are no simple answers or explanations for such questions. I'm still trying to fully comprehend musical modes and remember chord structures.

String instruments which are played regularly are typically "kept in tune" for many decades on end.

Strings may be damaged by age or environmental factors, of course, but, in my opinion, the minute aspects of wooden bodies' shapes are better preserved if string tension it maintained. If you unbox a dulcimer with loose strings it usually takes several tunings to get it to hold properly. Tension also keeps the "bridge" and nut secure.

Wooden pegs are another matter. They and the matching holes will undergo changes in roundness with changes in humidity. That's why moving a dulcimer from Phoenix to Seattle may require attention by a luthier.

If you have a 10 million dollar violin, controlled storage conditions are probably in order, but the primary benefit goes to the gut strings and horsehair on the bow.

If your dulcimer is worth less than $10,000, keep it in the case and keep it out of rain, snow, deserts, and floods. Storing it in direct sunlight probably isn't beneficial, but a lot of wall-hanging dulcimers stay playable.

Except that mine is Dd-Aa-aa (or maybe dD-aA-aa, or aa-Aa-Dd if you prefer the reverse order)

Or like an "unreal Dulcimer." On my 6-string dulcimer, tuned in DAA with 6+ fret, I have a wound string in the middle pair tuned an octave below normal and a high D on the "bass" pair. This gives a more rich sound to the drones, and not like a mandolin.

I also like the sound of 3-string DAA noter-drone cardboard instruments.

As John and others say, depends on what you like and the mood you are in.

I ran into a problem with a wound bass string once. There was a bit of a buzz which I tracked down to a broken winding. See the attached photo.

I identified the problem when I ran my finger up and down the string. It was visible to my naked eye once I knew where to look.

A simple string change fixed it.

 Damaged Winding-labeled.jpg - 496KB

Ukulele fret boards are essentially the same width as those on dulcimers- about 1 1/2 inches. Guitar pickups are wider, but they say they can be cut. That's why I pointed to the ukulele version. 

The piezo element itself looks sort of like a black match stick with a wire on one end. As I recall, I think I just cut the height of the "bone" (probably plastic) saddle down, slide the pickup into the slot, and put the saddle back on top. Some ukulele people appear to put it along the outer edge of the bone saddle, probably raising the strings be a tiny amount.

The rest of the procedure is covered reasonably well in a number of YouTube videos. I think this one is pretty good.

Installation of ukulele pickup system

If you are doing it for the first time, you might want to do it on a cheap instrument.

It does take "some skill," but not a whole bunch. My kit came with paper templates for the holes. Other than a drill, I used only hobby/craft hand tools. The wiring is all plug-in, and the holes you cut for the tuner/controller and battery/jack boxes allow you to pass the wires for hook-up.

Since you have a serious need for a pickup, I would not suggest a stick-on mounted on the face of the dulcimer. Particularly since you say you feel sounds from other instruments on it.

I would suggest a piezo pickup under the "bridge" of the sort shown here.

https://www.ebay.com/itm/154154723887?_skw=ukulele+underbridge+pickup&itmmeta=01JR0P8CXC59HVTZEX0R9G8PKC&hash=item23e4566a2f:g:zdYAAOSwiO9fkRip&itmprp=enc%3AAQAKAAABAFkggFvd1GGDu0w3yXCmi1f1a%2FKcJRUkgjxwQyqQw7pljhCoSpJkPekGjrv%2FHmQyoDfqDnxjm6SrWceacTwHEpxive6LhrBaCArs25TycThyGZw2SwBCOiSvptCm5%2Fqzop1Fsc%2FQiJa4vvGCcKXGJPDVPubYXyW6kOSyQwGuZ3Yc3CZRgqJImQu%2F%2B6SWoTgeXfbx0g2Uo33cGOepI4b5%2B9dx0tzeZAB1uEmGVfOOhjkaI1%2F%2BVJO7Y60fW7j1TotNy7taAUvEFBrHgSRsWpZNray4sM%2Fk9HoLN2Gz0D1ObyGt3wf8uRJdkfhoChJR0GG82SBarYMYfHYCdb8cCuCEjWg%3D%7Ctkp%3ABk9SR_7OoZbAZQ

If installed with the pre-amp/tuner you add many of the features found on electric guitars, etc. I installed a similar unit on a cheap, used dulcimer, and it works. I don't use the pickup since I play quietly in an all acoustic group, but I have tested it with a 10 watt guitar amp and it works well. I do use the tuner - it doesn't get lost in my case.

The lower instrument in my photo on the left is one I made a few years ago. The VSL is about 15 inches and it has a standard string set. It is tuned to DAA, but an octave above normal - A = 440.

It has a nice sound, but I have hardly played it. I had in mind that t might be used in an ensemble for adding accent on a second verse, or whatever. I haven't had an opportunity to try that with our group.

"3 mm is ok., 2,8 or 2,9 mm too."

Adding the metric measurement is good. We should remember that "The Appalachian Dulcimer" covers the world today, and that we should routinely mention both American and SI units.

Many of us are used to thinking 1/4 inch plywood is 6mm and 3mm ply is 1/8 inch.  Actually 1/8 inch is 3.175 (3,175) mm, so "by eyeball" we are talking about the same dimension, making 2,8 mm a bit narrow for some of us.

A 3+ fret might have been used to play ancient or Eastern European tunes which have different ascending and descending scales. I think I've run across tunes where either a 3+ or 4+ was needed in DAA. Dulcimers can be highly individualized, and a "one-off" by a home builder is a possibility..

One measure might be the number of commercial producers of dulcimers. That has certainly declined.

Buying a new fretboard will cost you more than buying a 30 year old dulcimer and involve a lot more work.

I would suggest you consider buying an instrument on ShopGoodwill for $40 or less (including shipping and tax) and adding a cheap contact mic as an easy experiment. Since you will be shaping the sound with your electronics the body quality will make minimal difference.

Most of the instruments listed today on this page should serve your purposes. (I wouldn't say that to someone looking for a good acoustic instrument.)
https://shopgoodwill.com/categories/listing?st=dulcimer&sg=&c=&s=&lp=0&hp=999999&sbn=&spo=false&snpo=false&socs=false&sd=false&sca=false&caed=1%2F22%2F2025&cadb=7&scs=false&sis=false&col=1&p=1&ps=40&desc=false&ss=0&UseBuyerPrefs=true&sus=false&cln=1&catIds=&pn=&wc=false&mci=false&hmt=false&layout=grid&ihp=true

Professional Piezo Contact Microphone Pickup for Guitar Violin
ApproximatelyUS $2.57
Free Economy Shipping from Greater China
https://www.ebay.com/itm/335756608848?_skw=piezo+pickup&itmmeta=01JJ71EA19DF3XA0WECP531VMD&hash=item4e2ca74550:g:qpUAAOSwOPtneM1U&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKn2D4rzConcs1ki1Ui1XNKWM5p388NzRr7ctDbXkTg6jyJXUfQdgUK8S78UJ8CEyq5hhXsVafRrR2CmyoZFkhZIr6ptQzZxbUkoPa1y8kHxgLFENxppmRqORstXXLebiwlUtzcON8kk%2BQ%2FCVmfqUCqAghklDiAyP--nOGKZkfYA8l4lDa4g4v%2FxSWJZRKdGKAdDheOD5n6lpYerGCVv87BKQm%2Fzn6B%2FyPhEy1mITwdBR5r9powtvrK7QZKusCtkFtvkUwgn72gmxUb%2FDk4tJ%2FXl1tCRa%2BrVCKCr5R11UoHUCw%3D%3D%7Ctkp%3ABk9SR_6gueGRZQ

My knowledge is in two streams.

I use and arrange in MIDI for a crank organ with multiple voices controlled by solenoids, as well as a small MIDI synthesizer module.I don't think this has any bearing on your needs.

On the dulcimer side, I have used a $10 clip-on guitar pickup experimentally on a $40 dulcimer.. That worked as a connection to a 10 watt guitar amp.

I installed a ukulele tuner-preamp with piezo under-the-bridge installation on one on my $40 Korean dulcimers. Mostly I just use it as a tuner which never falls off or gets lost. I have tested it with a couple of small guitar amps, so I know it works, but I only play for fun with acoustic groups. I have thought it may be useful when working as a dulcimer class instructor, but found my home-made acoustic Tennessee Music Box dulcimer works well for our very small classes, and is convenient for use on a table in the front of the room.

If you already have any dulcimer, try a cheap guitar pickup first.

A solid body electric is fine, but probably expensive, and will have to be custom built with a considerable wait time.

.

It's not clear to me exactly what you propose to do.

In general, control of a synthesizer requires that the controller generate a digital signal, which is commonly in MIDI format. No pickup on an acoustic instrument can do that.

A dulcimer with a pickup CAN generate an analog audio signal which can be added as a digital stream in the output to a final audio file.

Can your system deal with input from a microphone or a common electric guitar? If not, an electric dulcimer will be no different.

I think any "set" on the market will be fine on any more-or-less standard dulcimer in CGG, DAA, DAD and DAC tuning. There is no reason to try to out smart McSpadden, or the other industry leaders

That is assuming you start a bit low and carefully tune up to the note you want. A beginner can accidentally tune a few turns too high too quickly and break a string, and I think part of the selections used in making sets make an allowance for that.

I think you can go up to 14 on the melody strings if you stick to DAA, but 12 is safer for DAD, and 10 requires less finger pressure. DAD players typically finger about 3 notes on the 14 middle string, anyway, so 14 A is playable.

Finger pressure is also dependent on string height which is also a personal choice. Have you mastered checking and adjusting that yet? Builders often leave strings a bit high to allow easy adjustment with a small file if they don't use a zero fret.

"Chromatic Dulcimers are becoming more popular" Than what?

Many, many more new violins are purchased each year than dulcimers. Probably many millions more.

I play 3/4/6-string noter-drone dulcimer for simple fun even though I'm about as comfortable on the violin. I'm not aiming for mastery of either, just my own amusement.

Why are you worried about tuner precision? Electronic turners are great for many reasons, including letting folks "tune up" backstage to the same note, instead of devoting a minute or so of on-stage time, but in my opinion, a few cents difference doesn't really matter.

In the real world when you take your dulcimer out of its case and try a tune it may sound fine, but the happy person next to you sounds out-of-tune. You get out your tuning meter and find you are a bit off because your strings are at a different temperature than they were the last time you played. In the old days, you would have said to the leader "Play me a D," and tuned to that, the group being more important than you.

Tune your middle A string as precisely as possible (in the green) and then test the tuning when you finger at frets, 3, 7, and 10. On many, perhaps most, dulcimers you will find you are a few cents sharp, but when you play music it sounds fine.

If you put your finger on the string and check the tuning, you may even find that it makes a difference where and how you place your finger.

On large organs, pairs of pipes are tuned with one a few cents sharp to produce a voice called Celeste, or a few cents flat to produce a voice called Humana. Slight dissonances make music more interesting.

As the old saying goes, "This ain't rocket science."

Your picture of the "bridge" end doesn't show enough to make good guesses about it. Two photos, top and side, could help.

A straight on side shot of the head might also help. There are, I think, quite a number of variations of that "leprechaun" shape when all builders are considered. We might match the profile.

The tuner set-up interests me. The wholes are drilled straight through as though violin pegs were to be used, but the tuners installed are banjo or ukulele type.

Hill Country Dulcimers, successor to The Dulcimer Factory (TDF), used a variation of that style head and a zero fret in 2002. Possibly TDF also made a model in this style. I think both produced kits.

See the following for an example.

https://reverb.com/item/60222347-vintage-handcrafted-hill-country-dulcimer-fredericksburg-tx-hummingbird

You don't need to buy a replacement blank made of bone, or other super-hard material. Those can be a good choice, but they are hard to shape.

You can use hard wood. that is easier to shape with sandpaper. You can start with a longer piece to make it easier to hold.

It is important to properly slope the slots, not just space them correctly. The inside edges need to be higher. The slope may not be readily visible on the original.

The slope or curvature of the top isn't musically important.

By the way, I don't think the question of a "zero fret" has been raised. If you have one, the "nut" is just a spacer, and all this discussion is irrelevant at the head end.

Ken Longfield said "Back in 1974 I would guess that McSpadden recommended using a wood glue like Original Titebond or Elmer's Wood Glue."

I would agree as far as kit instructions go.

The "factory team," including kit assemblers, might well have been using hot hide glue mixed from powder.

see: http://www.makingtheviolin.com/Glues

Most other wood glues for serious work only became available after about 1950, and the traditional stuff still has a following, partly because it can be disassembled with modest heat.

The page is

STRING TENSION GUIDE FOR ACOUSTIC GUITAR
It includes equations and the weights and cross-sections for various GHS strings plus a number of tables.
"GHS has used the 25.5” scale length (typical for Fender) in the enclosed guide. Your individual instrument may vary."

This involves more work than I am willing to undertake. I'll stick with the usual "dulcimer strings."

http://www.ghsrep.weebly.com/uploads/2/2/2/5/22258814/2020-ghs-acoustic-guitar-tension.pdf

Sloppy URL citation. This gives access to a relevant document

http://www.ghsrep.weebly.com/uploads/2/2/2/5/22258814/2020-ghs-acoustic-guitar-tension.pdf 

Bing Futch has a good 9-year old video - Dulcimerica 273 - "Sliding On The Resonator" - Mountain Dulcimer

His instrument is very much a "non-standard" one.

He suggests, among other things, that you may want increased string height and possibly no frets for slide playing.

Ken's suggestions about trying wound strings look good to me.

Good luck on your explorations. Please give us some reports since there is little information on slide playing available.

Most slide work seems to have been done with electric or resonator dulcimers, not traditional bodies. These give a much stronger sustain to the notes. Much of this is done with extended string sets, going beyond simple DAD tuning.

My playing is in DAA, and I have no plans to do DAD.

I would say that you will be pushing your luck if you try to make the melody string heavier than an .012 - there are good reasons why we don't find .014 melody strings in the "dulcimer" sets sold, although they might sound better for us DAA folks.

I like a low middle string, tuned below the bass D. I've used an .028 for that, if my memory is correct. That won't work well in DAD because you can't then move to the middle string to get the low A in a melody.

I am currently the custodian of two "cardboard dulcimers" which have been used in classes and as loaners for about 20 years. They still play well, although their cases are plastic bags. I used them two weeks ago to demonstrate the difference between C-G-G and D-A-A tuning on identical instruments.

I will emphasize that only the bodies are corrugated cardboard. The sticks are 1x2 lumber, and they have guitar fretwire frets, and regular tuners and strings.

A huge part of the true cost of making "a real dulcimer" is in the sanding-varnishing-sanding-varnishing of the wood body, and this has no effect on the sound.

 Cardboard with Numbers.jpg - 71KB

Have you actually played both of them? If you are buying a musical instrument, the sound and the way it fits your playing should be the deciding factor.

You might consider looking at Jean's The Dulcimer Book. She has a TAB for Barb'ry Ellen on page 27, along with about 12 verses of lyrics. The record you are using has the same cover photo as this book.

The TAB is in the old C-G-Bb tuning (Aeolian Mode), but plays just the same in modern D-A-C tuning. There are no chords, it is Noter-Drone in that version.

In my opinion, Jean's The Dulcimer Book. is the best single lap dulcimer book ever written. It is still in print and used copies are typically under $15 including shipping.

I watched Robin Clark's video. He does a great job of covering dulcimer types and construction, and he plays with great skill.

On the other hand, I don't think he really understands the place(s) of the dulcimer within Appalachian culture. He proposes that the dulcimer was commonly used for dances and church services. I have seen no evidence that dulcimers from our area were ever used in dances or church. 

Both from reading Jean Ritchie's Singing Family of the Cumberlands book (Eastern Kentucky) and from studying local sources (North Central West Virginia) I am aware that in many communities dancing to instrumental music was considered sinful. This was particularly true among rural Methodist and Baptist congregations. In those communities "children" of all ages attended PLAYS or PLAY-PARTIES where dance-like activities took place while the participants SANG the music. 

There are many scholarly and semi-scholarly books which discuss play-parties in detail. In many cases the tunes and dance figures were nearly identical to fiddle tunes and square or line dances. 

Dulcimers were not more affordable than fiddles and banjos. Both box and gourd homemade fiddles and banjos were used by others (Presbyterians and Anglicans ??) within the same areas for dancing.

As to dulcimer playing in church, I'd guess that it occurred on occasions, but it was unnecessary. The Ritchies, and probably most other Methodists and Baptists, learned highly structured unaccompanied singing in shape-note schools and from the Sacred Harp schools. It is quite possible that many of the small churches had foot-pumped organs, there was one in the Ritchie home. 

If anyone has primary source material describing dulcimer playing at dances or in church, I'd like to see it.

Buying a new bow probably makes sense. The cost of re-hairing one in the USA is higher than a new one from China.

A half-size violin bow is probably a pretty good choice, but also look at child size Cello or Viola bows. They will be a bit heavier.

Percussion stuff. I'm playing percussion in a small concert band, and sometimes play spoons with our dulcimer group.

It may be worth while to invest in a wire gauge if you need to replace strings. I have one like this which I occasional use on dulcimer strings.

I would guess that a relatively small number of sizes are required, so you might want to buy coils of wire. Otherwise Folkcraft and others probably have suitable choices, but "too long."

https://www.ebay.com/itm/315386837794?itmmeta=01J3DM58WKFSA07Z72Q1ZXBVB4&hash=item496e853b22:g:J-0AAOSw6eBmTuYv&itmprp=enc%3AAQAJAAAA8OE2Ww6YtOA65E8nF2yJ%2FRPTX6XJJT1daeFK0r1%2Fmn3u3uEoh4n6NL%2Bdxuqnw0MydXCDemBnkiFWZHZo2jqH1xLjVWWcF6MzzxsGKQLKMgkUg82IEIG6EoaQ59uBJDDl0Jp7OxcobsxPk4FNtfgl0HMi74MyC0Ar6yYUhYjj%2BmQve7mIwIOs8JRFCu2pnasa7Z8SaTsy46Dt--vOFko1zsNlMcB5oMvhSl6k%2BILWdzhUJHdOY9c3wJ4o6nG36lXEAtq1i2sVnJEuZI7BmoFJpK1dSdtnI8KAG9ikbAXqgMBgEw2UTumzGYRGvNa8at%2Flgw%3D%3D%7Ctkp%3ABk9SR7qOlbSbZA

OK, now I understand the requirements. Just have a blacksmith or welder construct five separate cradles, each customized to fit an individual instrument and at your chosen angle. A single hanging point for each is all that is needed. Make them from heavy steel wire (8 gauge ?), paint them black, and cover the contact points with black rubber tube (1/8 in. ?).

This approach requires good craftsmanship which won't come cheap. You could by another good dulcimer for the same price.

You might also consider building some sort of angled "bookshelves" or "shadow boxes." That way you could easily take them down to play.

The closest thing I can find as a picture is on

https://www.amazon.com/Rolanstar-Bookshelf-Bookshelves-Bookcase-Organizer/dp/B0CLD2KJLK/ref=asc_df_B0CLD2KJLK/?tag=hyprod-20&linkCode=df0&hvadid=693769995770&hvpos=&hvnetw=g&hvrand=12067035090039566209&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9009439&hvtargid=pla-2273008037708&psc=1&mcid=c43bb487d9ec3f929b6e7a208188e8a7&gad_source=1

I ordered a set of the tuners on Ali Express for under $15 for a set of 4. I used PayPal to avoid sending a credit card number. They arrived promptly, considering their origin in China.

They ARE 4 to 1 planetary geared units. I wouldn't give them the 1 in 5 rating another buyer gave but more like a 2. They look good but the quality is poor. Two of the four had flash on the castings which should have been removed before plating and needed clearing before the retaining barrels would insert. All four were a bit jerky in turning, and the barrel threads may or may not work to full depth.

Aside from quality, they have a downside in that without making special spacers, they will not fit wood less than 0.4 inches thick, and maybe not under 1/2 inch so they aren't good for side mounting. They are described as "banjo tuners," however.

I haven't tried fitting them to anything. I'll almost certainly put them on a stick before risking any bodied instrument on them.

Research is never free, and $15 isn't a big expense.