Tuning Machine Mounting

[Steve Etter]

As I was preparing to layout the hole locations for my yet-to-be-purchased tuning machines, I noticed that Siminoff has the two machines angled slightly toward each other rather than parallel as it appears are so many other designs.

I was wondering a couple of things about this. First, how are they layed out in the Loar plans (I will be buying a copy of HoGo's prints once he releases the new ones, so for now I must ask) and, second, does anyone feel there are any particular pro's or con's to one way or the other?

Steve

[Lefty Luthier]

I always set the outer pegs 0.120 closer together than the inner pegs. This provides just enough clearance, when combined with the nut spacing, for the outer strings to miss dragging on the next peg. I doubt it makes much difference but I believe it looks better. When laying out your holes, make note of the width of the tuning machine base plate so that it doesn't stick out past the edge of the peghead. Also drill from the back side to insure that the base plate lies flat when the tuning pegs are pressed through the holes.

[bennyb]

Howdy Steve,
I can't answer the questions you posed, but I would strongly recommend having the tuners in hand before drilling any holes.

My best, benny

[Steve Etter]

Thanks. I was kind of leaning that way (getting the tuners first) especially after reading a post recently where someone mentioned that they sometimes have to relocate the holes depending on which tuner they get.

Now to select....

[bennyb]

Remembered a couple other things from the first time around. You're going to drill holes the size of the bushing, you'll have to measure that and check that it works in a piece of hardwood scrap. I did that then made a 4 hole template out of hardwood to clamp to the peghead. You'll also have to decide whether to drill through at that size or step down for the narrower posts.

Good luck, benny

[Steve Etter]

You'll also have to decide whether to drill through at that size or step down for the narrower posts.

Bennyb -

I understand the first part of what you are saying, but I don't quite follow this.

Steve

[amowry]

I think it just depends on your headstock design. One F5s I keep the baseplates parallel, but I know of lots of others who do it differently.

[bennyb]

From the back of the peghead, the holes only need to accommodate the posts(e.g. .25"), but from the top the holes have to be sized to the bushings(e.g. .33"). If you just drill the bigger hole all the way through, it's still covered by the tuner backplate, but not everybody does that. The "big hole" approach gives you a little more wiggle room, but not as much as you might think. As usual, precision is still important, as per Lefty's comment, the base plate only lies flat if the holes are perpendicular to the back.

I may have introduced more complexity than was strictly necessary. :-)

benny

[grandcanyonminstrel]

Steve:

I'll second the idea that before I drill any holes or do the final peghead profile, I always like to have the machines in hand. I also reccommend using the Stew mac tuning machine drilling jig- works fantastic, fair price, and it is simple. I usually keep two in the shop at all times- one standard and the other Loar configuration. Whenever I or anyone else question the spacing of a set of machines, we just pop them in the jig and you know instantly; it is a nice tight fit and very accurate.

j.
www.condino.com

[Gail Hester]

I install tuners as James said with the StewMac drill jigs.

I also use a Loar templates to position the hole pattern for the jig for all style mandolins/mandolas. I don't assume that the tuner button shafts are the same from one set to the next and always make sure the tuner buttons will clear the headstock all around before I drill any holes.

I think it's a good idea to drill the thru holes properly for the posts with a counterbore for the bushings. I use the Waverly drill bit for those and match drill bits for other tuners and bushings. Depending on the bushings sometimes the right sized reamer is enough to achieve good fitment.

[sunburst]

The tuner hole positions changed during production of the Loars. The early ones had holes that diverged going away from the nut and later ones had holes that converged going away from the nut.
In other words, the tuner plates were not parallel on Loars, but the convergence of the plates changed sometime in 1922 (I think) from the older F2/F4 positions to the more familiar "Loar" positions.
If you drill holes large enough for the bushings all the way through (no step drill) it is not important if the holes are perpendicular to the front or the back of the peghead, so they can be drilled from either side. I build with a tapered peghead and I drill perpendicular to the front face of the peghead. There's no problem with the tuner plates or the bushings lying flat on their surfaces.

The advice you've gotten to drill the holes accurately is spot on. The holes for each tuner need to be evenly and exactly spaced and in a straight line. Using an accurate jig can do that, put for one instrument you can use magnification, an accurate scale, caliper and/or divider, a sharp point for scribing and "center punching", a small pilot drill and a drill press with an accurate brad point bit. That's how I made the jig that I use.

[Steve Etter]

Hi all,

Just thought I would update you all after receiving the sage advice to wait till I received my tuning machines before cutting the holes in my peghead. Well, today, I received my tuners and, guess what, they wouldn't have fit.

In the picture, I have set one of my new Gotoh GT-160-G machines on a piece of mahagony that I carefully laid out last week with the hole spacings as per Roger Siminoff's template.

Thanks guys.

Steve

PS. I have read something about putting them in a drill to kind of "break them in". I assume you are simply clamping the peg in a cordless drill and letting it run for a while?

[sunburst]

I don't think you'll need to "break in" Gotoh tuners. Unless something has changed since the last Gotohs I got, they have a little bit of built in looseness between the tuner plates and the string posts. That serves two functions; it makes them very easy to turn, and it gives them more tolerance for hole misalignment than many other tuners because the posts can deflect more without binding. String tension eliminates any loose feel that the tuners may have, and they feel smooth and work very well, in most cases.

[amowry]

I agree, Gotohs shouldn't need any breaking in.

With those new Gotohs I actually drill a counterbore on the back side of the peghead that is larger than the hole for the bushings, because I use the vintage bushings from Stew-Mac, and the washers at the base of the post are larger diameter than the bushing hole. This is the only instance in which I use a stepped hole of any sort.

In addition to making sure the holes for the posts are in the right place, it pays to make sure the pilot holes for the screws are well centered in the baseplate holes. I find it's especially important with Schallers and Grovers, because the screws are the countersunk variety, and they tend to want to center themselves perfectly in the baseplate holes. If the pilot hole is off a little the screws will pull the baseplate out of position. The other brands of tuners are more forgiving because the screw head sits on top of the baseplate and there's a little slop in the holes.

[Mike Bromley]

I install tuners as James said with the StewMac drill jigs.


What Gail and James said. Seems to me completely counterproductive to do anything without a precision jig, when it comes to aligning tuning pegs. A skewed shaft would be disasterous in my books....:grin:

[Geoff B]

I carefully laid out last week with the hole spacings as per Roger Siminoff's template.

I drilled using the Siminoff drawings once and realized the spacing on the holes is not the 29/32 it should be for many tuners (Gotoh, Schaller, Grover). I think it may be because he uses orthographic projection, but if you are laying out without a jig, DO NOT USE THE SIMINOFF DRAWINGS! I can't speak for him and i really appreciate his book, but I wish someone had warned me before I put 8 holes in that headstock.

[Steve Etter]

While I, like you, can't speak for him either, I tend to doubt your orthographic projection theory only because the hole positions show up on the same template drawing as the one used to outline the peghead. Had he projected the holes, it is my contention that he would have projected peghead outline as well. Were this the case, the overall peghead length would be shorter than it should be, too. I don't believe it is (but then again I don't know what the actual target is anyway).

Steve

[Lefty Luthier]

This is an excellent reason for using a drill jig as well as insuring perpendicular holes. I believe that Siminoff informs you which drawings are orthographic and which are not. I know that his page illustrating different inlays is correct so it could be copied and pasted to a peghead as a rough drill guide.

[Geoff B]

Trace once, measure twice, drill once. Or make/buy a jig.

[mandolinplucker]

I got a piece of steel rod and drilled a hole down the center the size of the tuner post. I then cut 4 pieces to make 4 slugs with a hole in the center. I got a piece of corian and drilled 4 holes slightly oversized for the slugs. I epoxied the slugs into the holes in the corian and before the epoxy dried I inserted the tuner shafts in the holes in the slugs and let the epoxy set. The slightly oversized holes in the corian allows the steel slugs to center to match the spacing of the posts. Clamp the jig to the headstock and drill. It's custom made for that particular set of tuners so they have to fit.

[sunburst]

Tony, I'm glad it worked for you, but many of the tuners I get have plates that aren't completely flat. That makes the tuner posts point in slightly different directions, and makes the spacing at the ends of the posts erratic.
I first noticed this when I had a set of tuners that didn't drop right into the bushings in a peghead. My first thought was that something had happened to my drill jig and the holes were not accurate, but upon investigating, I found that the tuner plate was slightly curved. Bent? Warped? I don't know, but after I straightened the plate, the tuner dropped right into the bushings like usual. Now I check the tuner plates every time I get new tuners, and I often find that they aren't perfectly flat.

So, anyone thinking of making a drill jig like Tony's, check the tuner plate first and make sure it is dead flat.

[Rick Turner]

Tony's method of making a drill jig is great, but you don't have to make the drill bushings yourself. You can buy hardened steel drill jig bushings from a number of sources; they're not terribly expensive, and being hardened, you can drill hundreds of pegheads through them before there's any wear at all on the bushings. Try McMaster-Carr or even some of the woodworking tool specialty sites.

[Mike Bromley]

I got a piece of steel rod and drilled a hole down the center the size of the tuner post. I then cut 4 pieces to make 4 slugs with a hole in the center. I got a piece of corian and drilled 4 holes slightly oversized for the slugs. I epoxied the slugs into the holes in the corian and before the epoxy dried I inserted the tuner shafts in the holes in the slugs and let the epoxy set. The slightly oversized holes in the corian allows the steel slugs to center to match the spacing of the posts. Clamp the jig to the headstock and drill. It's custom made for that particular set of tuners so they have to fit.

Plucker, that is downright brilliant. Moreover, the hole down the centre of the rod doesn't even need to be centered....

[Lefty Luthier]

I too have noticed that many tuners are delivered with slightly warped plates that cause the posts to point off line. I have taken to putting them into the drill jig and using a piece of soft wood as a caul, clamp the things hard for a moment. It straightens them out without the risk of kinking. This seems to most prevalent on recent Gotoh tuners. Has anyone else seen this problem?

[mandolinplucker]

John, thanks for the tip on the base plate. Never thought of checking that. I got lucky. I only used this method once and it worked fine but I can see where a bent plate would ruin my whole theory on the accuracy of the jig. I just love this board. Nice folks and a wealth of information.