Schaller A-style tuners

[John Soper]

A few questions before I screw up my courage to drill into the virgin headpiece with a friend's drillpress:

-are Schaller A-style tuners reverse gear with posts above the gear mechanism? No info on Stew Mac's website or in the box... they seem to turn in the correct direction when held in that orientation & played with...

-Siminoff's book describes drilling tuner holes from the front: wouldn't drilling from the rear with a wood backstop to prevent tearout allow the tuner posts to be at a right angle to the surface that the tuners are screwed onto?

-Siminoff talks about drilling guide holes, then drilling to the size of the post, then drilling to the size of the bushing. #I'm afraid of getting off-center with sequential passes of the drill- why not drill to the bushing specs to begin with?

-Schaller spacing is .906" between posts- how critical is the .906" vs .9 or .91" spacing for tuner function?

-The bushing diameter is .342" and post diameter .236"- should I drill with 5/16" bit (.31") & use a reamer to get a good fit, or is a 3/8" (.37") 'tight enough'? #Or do I need to get metric bits, do the math & convert to mm?

I'm going to make a template out of plywood or plastic first- practice & make sure it all lines up before proceeding with an irreversible FUBAR...

Thanks in advance- I'll ponder it at MerleFest ...

http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[HoGo]

I've never seen reverse cut Schaller A machines. Compare them to any open guitar machines which are almost exclusively standard (nonreverse) - that means that the string-post is closer to the nut than the worm. (the worm has right hand thread). On the reverse the worm is left hand thread).
The Schaller bushings are 10mm at the widest point. I drilled 9mm and had to ream almost to 10mm to get exact fit without risking a peghead split. (the peghead has ebony overlay). On the next I'd drill exactly 10mm throughout and use a drop or two of thick CA or some epoxy to hold them in place. The holes will be completely hidden on the back of the peghead by the plates.
Use some sort of jig to have the correct spacing (23mm) alignment and angle. Use good wood bit with correct size and don't forget to back your peghead with a flat piece of wood to prevent chipping at the back of the peghead.
Test the size of holes on some scrapwood first to be sure.
Just my $0.02
I hope somebody more experienced will step in.

[sunburst]

-The ones I have here have the post below the worm gear. A style tuners can be mounted either way. They will turn in different directions, tho. It's best to have your tuners in hand before drilling the tuner holes and even before designing your headstock.

-Yes. If you have a tapered headstock it's better to drill from the back.
Edit-Ignore this and see below.

-You can do it either way. If you have a good brad point bit, it will follow a pilot hole very well. The small daimeter bit for the pilot hole is less likely to "walk" when starting the hole.

-The spacing has to be very acurate or the tuners will be hard to turn.

-I'd drill undersize and ream to fit

[HoGo]

Sunburst, there was a thread about tapered pegheads a few months ago and as I recall just everybody recommended drilling from the top. That way the holes are perpendicular to the back of the peghead.

[sunburst]

HoGo, I've had more coffee now. You're right. The plates have to be 90 degrees to the holes. That means the back of the pegnead needs to be on the drill press table and you do need to drill from the front.
I think I was out too late last night to think correctly. Thanks for the correction.
Sorry for the wrong info.

[Chris Baird]

The link below is how I do it. I don't actually have the jig but the rest of the process works just fine without it.

www.stewmac.com/freeinfo/I-5007.html

[sunburst]

Chris, I've wondered about the durability of those drill jigs. How do you locate your holes without the jig? I assume you're using something else.

Actually, I drill mine with a "pin drill" jig that I made like the one described in the Benedetto archtop guitar book. It takes very little time to set up, it's very accurate, it doesn't matter how much taper is in the peghead, the holes are 90 degrees to the back.
I just wasn't thinking when I posted about drilling from the "wrong" side.

[P Josey]

sunburst,

could you post a picture or give a description of that " pin drill" jig ?



Paul Josey

[sunburst]

Paul, I don't have a digital camera yet,(soon I hope) so no pics.

The principal is the same as a pin router. It is a two part jig.
One part holds the peghead with some means of holding it in the exact right position. A little imagination is in order here; Benetetto references on the edge of the peghead so that it has to be shaped accurately and consistently first. My jig uses the width at the nut and a little spline that goes into a saw kerf in the waste wood in the center above the tip of the peghead. Whatever works.

I hold the neck in the jig with a toggle clamp.
The bottom surface of this part of the jig has 8 holes in the exact configuration of the tuner holes.


The other part of the jig is an auxilliary table that clamps to the table of the drill press. In it is a hole with a pin in it the same diameter as the holes in the bottom of the first part of the jig. I chuck a piece of drill rod in the drill press and pull the pin out of the hole in the jig. I align the jig by putting the piece of drill rod in the hole
and clamp the jig to the drill press table. Now the drill is exactly aligned with the pin below.

I put the proper drill bit in the drill press and place the jig holding the neck under the drill, slip each of the holes in the bottom of the jig over the pin in the table one at a time and drill the hole.

I don't know how easy that is to follow, but the Benedetto archtop guitar has a thorough explanation with pictures. There is a lot of helpfull information for the builder in that book.

[labraid]

I just measure with a good metric rular, 23mm between holes, (0,23,46,69 or more accurately, 10,33,56,79) on a straight line, hand mark the hole with an awl at each one, then use a brad point (very important, no tearout!!! available at Lee Valley) 11/32" drill bit in the press.. Bodda-bing, no extra templates, jigs, junk to clog up the shop and get lost/broken/smashed against the wall, ehheh.

keepin it simple http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wow.gif
-Brian

[peter.coombe]

After about 100 installations of Schallers I think I have got it figured out finally.

Forget Siminoff. Some ways he does things is just plain weird. The spacing of the holes is critical. Drill the holes from the top. I don't use any jig, but mark the hole positions out accurately and use a steel point to mark the exact position to drill. The hole is drilled using a 10mm brad point drill bit. Ordinary drill bits will wander and then spacing will be screwed up. Align the point of the drill bit up with the mark as the bit is spinning in the drill press. Drill the hole, but not right through. Brad point drill bits tend to tear out badly as they emerge so don't drill through to the other side. Once you have drilled all the holes, change the drill bit to a 10mm ordinary twist drill bit and drill the holes right through. That way the holes will be clean on both sides of the headstock.

You will tend to get some finish in the holes so they need to be reamed. Ream the holes to get a tight fit of the bushings, but not too tight. This takes a bit of practice to get right every time. Be careful with the reamer. It can stuff things up for you if you lean it towards the nut. Try and lean it slightly forewards, away from the nut so the pull of the strings will straighten up the shaft. I push the bushings in hard with the drill press as the final step.

Schallers can be a bit inconsistent in manufacture, with some shafts a bit stiffer than others, and you may need to fiddle around with the screws to get everything working properly. I also hate those plastic tuning knobs. They are too small and slippery. Wooden buttons not only look better, they work much better as well, but that is another story.

Anyway, if you follow all this, you should be able to get Schallers working very smoothly. They sometimes take a little while to wear in, but eventually will work smoothly and will not cause any problems with going out of tune. I always put a small drop of light oil on the worm before stringing up a new mandolin. As far as I am aware non of the Schaller tuners I have installed have worn out. Most problems with Schallers is caused by incorrect installation.

[Bandersnatch Reverb]

I'm not about to do this, but if I WAS gonna do it, I'd go down to Sears and get a crossfeed vice for the drill press and bolt in onto the drillpress table. Then you can make up a set of cauls to hold the peghead in the vice. After that, its a simple matter to line up a) the angle of the straight line of tuners, and b) the amount of inset from the edge of the peghead. After that - just work the crossfeed one way as you read the scales. If you go to far, back off a full turn and re-read in the forward direction to get where you want to be.

Anyway, thats how I'd do it. And those crossfeed vices are fairly cheep, less than $100

[Bandersnatch Reverb]

Also, reaming is much neater than drilling, unless you custom cut a forstner bit to do the work.

[labraid]

Peter, do you use Lee Valley brad points? They custom mill their own, you can't get em anywhere else cut like theirs, as far as I know. When I get through the peghead, my drill bit can't even go any further, I get this nice little cirle of maple stuck on my bit, meaning I'm all the way through. (i.e. it cuts so nicely at the end this little maple circle is left spinning, block the cutting teeth, and you can't press down any further) I have to stop the drill press and remove that little piece, and the exit hole is as perfect as pie. Lee Valleys brad points are really the stuff... And never had to ream my holes either, very good fit.

[Dave Wendler]

My basic headshaping process....

I get the top flat on the peghead face using my jointer. Bandsaw the back of the peghead using a squared block on the bandsaw table. It's EXTREMELY critical you have an accurate and well set up bandsaw. I leave the back of the peghead about .050" thick.


Glue on the face veneer.

I have the peghead shape and hole location points in a simple drawing program in my computer( Autosketch ). I print the drawing on light card stock with my inkjet printer. I then glue this to the peghead face...spray contact cement on the paper.

Now, since my location holes and peghead sides are drawn within a thousandth of an inch or so(the program/printer draws a .005" wide line)....drill the holes...making sure you are holding the peghead TIGHT against the backing block...a brad point or forstner is necessary.

Now I'll go over to my big drill press and mill the back of the peghead to final sanding thickness; I use a 1/2" router bit at the highest tool speed. BE VERY CAREFUL...DANGEROUS....There is a tool called a "Wagner Saf-t-plane"...but I've yet to find one....supposed to be safer....

Then I do final outside shaping of the peghead on bandsaw/beltsander. Soak the paper template with mineral spirits and remove. Ready for final sanding.