tuning machine measurements

[Darryl Hattenhauer]

I have a decent playing and sounding home-made no-name 4-string mando that I want to turn into an 8-string mando. The peghead (made of mahogany) is small, so the problem is fitting new tuners onto the peghead.
It's not a good looking mando, so if I have to drill some holes that will show and leave old holes showing it's ok, but I'd like to avoid it.

One possibility would show no new holes. Take off the four cheapo original tuners, put two small tuners in the old holes, and add two more between the old holes. (You'd be turning the old second-string post hole into a fourth-string post hole, and then fitting two new tuners between them.) In other words, if you have little space between the first-string post hole and the old second-string (A) post hole, which tuners can you put next to each other that will result in the shortest distance from the center of the first tuner's post to the center of the fourth tuner's post? (I'm guessing mini-Grovers, but there must be others.)

Another possibility is to put on two 4-on-a-plate tuner strips. Is there any source on line that lists the measurement from the first post center to the fourth post center for various makes of tuner strips?

[mandroid]

Stew mac has drawings of the specs of their stocklist.

I have some un used Schaller bushings [PM about them if desired] , they are broad flanged,
so will cover re-drilling mis allignments bit ,
but doing it right would have a veneer laid down on the peg-head face, then drilling the holes.

drill press? allignment matters, you drill the holes square to the back
as that is where the plates are, tapered thickness is compensated for that way.

[Darryl Hattenhauer]

Thanks, Mandroid. That's all I need. Mini Grovers take up less space than the 4-on-a-plate I've found.

http://www.stewmac.com/shop/Tuners/G...s.html#details

If I need the bushings, I'll let you know. The guy across the street will do the drilling, and I think he can do it because he's a furniture maker.

[EdHanrahan]

Yeah but... I'll bet that eight mini-Grovers are at least a bit heavier than the usual mando plate tuners. Not sure how much extra peghead weight it takes to make it uncomfortable, but I suspect there's a reason that mini guitar tuners don't show up more often.

[mandroid]

4 of those sealed grovers are on an electric mando here.
some builders use them on long necked instruments.. they are heavy in sets of 8.
and the spade shaped knobs need more room than the round ones on most mandolin tuners..

N.B., there is a difference in the gear ratio to note, 18:1 , 16, 12,.. it is certainly easier to fine tune with a lower , than a much higher ratio,
with inelastic steel strings, short scales of mandolins, banjo-mandolins,

I found friction tuners, 1:1, a pain to get tuned up.

( found they, 1:1, are OK with elastic nylon strings)

[Darryl Hattenhauer]

Ed and Mandroid,

All true. Mini-Grovers are definitely heavier. So I'd prefer finding some 4-on-a-plates that would save as much room and fit the two original post-holes, but such a thing might not exist. And custom making one would be expensive, right?

And as you say, the knobs on mini-Grovers are too big. Are there any knobs out there that you can put on mini-Grovers for more room?

Darryl Hattenhauer

[EdHanrahan]

Are there any knobs out there that you can put on mini-Grovers for more room?

That's the kind of question where Stew-Mac can be REAL helpful on the phone. Good Luck!

[mandroid]

You may be able to find a set of 12 for those 12 string guitars, as they deal with a similar thing.. .

Gotoh has a similar niche product they use an oval sort of button.

Rigel made an instrument with 4 slot head tuners and 4 flat peg type head tuners ,

cleverly adapting a build idea pursued by those Rickenbacker Guitars back then , 60's
[and now I suppose]


[edit]I have several 4 string instruments , that I like just fine..

[John Flynn]

I'm surprised no one has brought this up yet, but I would worry that an instrument made for 4 strings might not handle the the tension of 8 strings without some serious neck reinforcement.

I had a old, no-name, Asian-made mandola that someone gave me that literally came apart when I put a modern set of mandola strings on it. I guess it was made for ultra-light gauge only. The instrument meant nothing to me, but the sound it made when it came apart still haunts me.

[Darryl Hattenhauer]

John,

Yes, I'm going to use ultra-light strings and maybe tune them down. This won't play very easily or sound very good, but I believe in taking care of instruments even if they are cheapos.