Machine heads.

Machine heads. No, we are not talking about a Deep Purple album, but possibly the most important item on your guitar or bass.
What is a machine head? Well, some folks just call them tuners, tuning machines, string tensioners, winders...and a whole lot more. Proper terminology.....machine heads.
Why? Well, that is because that is exactly what they are, and what their sole purpose is on the instrument.
The machine head is usually made up of two gears that mesh together and drive the shaft that the string is attached to. One gear is a worm style and the other is a helically machined spur gear. The tuner button shaft, or 'input' shaft drives the worm that in turn drives the spur gear.
The tuner button is usually driven onto a splined shaft to avoid slippage, and keep the machine positive at all times.
Years ago, the machine head consisted of what is similarly used on violins to this day. The tuners were hand cut dowels, that were tapered and usually made up of a very hard wood such as ebony. These were installed into tapered holes, and the string was fed into this tuner by means of a slotted peg head, again, quite similar to todays classical (nylon string) guitars and violins. One would simply turn the tuner until the string had reached the desired pitch, then they were pushed into the taper to lock the string in tune.
This didn't serve to work too well with the guitar, because as string designs changed, it became more difficult to both tune the string and maintain that it would stay in tune.
Hence the machine head. Based on the old 'leverage' principal, turning the tuner shaft against the spur gear proved to be less of an effort, they maintained (well...sort of maintained) their tuning, and did it with a lot less effort.
When I mentioned they 'sort of' maintained their tuning, well, let's just say they have come a long way since back in the day. String tensions were greater back then than what they are now, due to the fact most of the strings were bronze wound steel core strings. And the core wires were huge in comparison to what they are now. So, a lot of times the guitar machine would slip back on the tension that was applied to it. One would literally watch the guitar tuner turn backwards while they were playing. And this didn't just happen to the old Silvertone's, Kay's and Harmony guitars, but also to the Gretsch's, Gibson's and Martin's as well.
How did they get around that? Simply by 'building a better mousetrap', or so to speak.
They had to redesign the early machines from their original gearing that was a 4:1 ratio, and increased that to an 8:1 gear ratio. They also cut the teeth on the spur gear on a slight angle, opposite to it's direction of travel. This helped in reducing slippage and back-lash on the gears.
Though standard machine head gearing has increased again to a 16:1 ratio, other improvements such as pilot shaft clutches help to reduce string slippage and increase tuning accuracy.
What is the best tuning machine out there today? Well, that depends on what you are looking for. One might want accuracy and not care about style and looks, while another might want the whole package.
There are many to choose from, such as Grover, Kluson, Sperzel, Schaller, Waverly, Gotoh, and so many more. There are also some really good machines that won't break the bank, like Profile and Planet Waves, and some companies even make their own machines, Fender and PRS to name a few.
My personal favourite is the Schaller machine for electric guitars and basses, and I would have to say Gotoh for acoustic guitars. Why? Well simply because, like so many other things that are made in Germany, they seem to out perform most, if not all of the others in some way. Schaller's 2030 Locking Machine is by far, one of the best on the market today, and with the inclusion of their new 18:1 series, you will have to go a long way to find a better machine. These are a little expensive, and can be harder to find than most, but they are worth the extra dollars.
Gotoh is a Japanese product, and for acoustics, and some electrics, such as the Strat and Tele, these machines are hard to beat. They are reasonably priced and will last for years. Like the German's, the Japanese also know how to build a very competitive product.
Now some of you like to look into modifying your instruments, and that usually starts with the electronics and bridge components.
Personally, I say do yourself a favour and start with the machine heads. Get yourself a set that will fit your guitar's original design. You should never have to re-drill holes or add screws. Your new set of machines should be completely interchangeable with the original set. Don't modify your guitar to fit the machine heads. You will only de-value your instrument and you can really mess things up if you are not sure of what you are doing.
If you are not sure of what to do, seek out someone in your area that is knowledgeable about this, and together I am sure you can weigh out your options.
I didn't talk specifically about guitars equipped with the Floyd Rose tuning system, and there is reasoning in that. The reason being, that will be something to talk about next time.
So, until then....stay tuned!!
Cheers!

Brett McNaueal

Proper string height (action)

A lot of folks ask me what the proper string height should be on an acoustic guitar, and on an electric guitar. I even get asked periodically what the proper string height should be on a bass guitar.
String height is also referred to as 'action' on a guitar.
The answer to this is....'it depends!!'
An optimum string height for an acoustic guitar should be about 1/8" at the 12th fret. For an electric, about 3/32" at the 12th fret.
Proper string height depends on a lot of things, and this is the way I look at it.
The first thing you want to check is, has there been any work done to the instrument recently, frets repaired, levelled or dressed and polished. Believe it or not, this can make a huge difference in the performance and action on your instrument.
I have had guitars come to me, both electric and acoustic that have had a few frets replaced. These are usually the first three or four frets closest to the nut. I have seen some major league 'hack jobs' where the fret wire is not even close to then original size. As a result, the string height had to be raised so the strings would clear the new frets. This made the instrument virtually unplayable, and was usually a nightmare to undo what misery somebody else had caused.
So this is #1 in our continuing saga of string height.
#2... is the truss rod adjusted properly so as to maintain fret clearance to the 12th fret?
This then, gets us back to the slight 'dip' that you should see in your neck, while looking down the fretboard from the headstock. Again, this is very important in maintaining proper action on your guitar. If you are unsure of what it should be, and you don't really feel comfortable adjusting a truss rod, then bring it to someone you know and trust with your instrument. Back to the place you bought it is usually the right thing to do.
When the strings are removed from your guitar and the neck is at 'rest', you should be able to place a straight-edge on the fret board, and it should be completely level, or very close to that.  If not, you have a problem. You never want to see a crown on your fretboard, as this could be a result of over tightening the truss rod.
I have had people come to me and told me they tried to adjust their truss rod, and 'nothing happened'. Well, something 'happened' alright. What usually happens in a case like this, is the truss rod was broken as a result of over-tightening.
The other thing that over tightening of the truss rod can cause is 'twisting' of the neck. When this happens, if left for too long, it is almost impossible to restore the instrument, at least without some major surgery. And that can become very costly.
#3...So, what else can cause problems with string height?
Here are a few:
New neck, neck components. Neck reset on an acoustic guitar. New frets. Fingerboard re-levelled.
New bridge components, saddles, pickups installed below the saddles on an acoustic guitar. A new bridge on your electric guitar that you thought should be a retro-fit because it came right from Gibson. 'Not!!'
I have been working on guitars for close to 50 years now. Seldom do I put any creedence in the terms "cross reference", "OEM", "Original Vintage Replacement"or "retro-fit". No two guitars are built alike, not even on the same day, and seldom are the components. So any of these items can be a problem for maintaining proper string height.
#4 Here is probably the simplest cause of improper string height.....did you just change, or have your strings changed by that professional fella down the street?
Did he install the right gauge set for the guitar?
I remember being in a store locally not so long ago. A gentleman came in and asked for a set of strings for his Ovation acoustic. The store owner, who should have known better, sold him a set of medium / heavy gauge strings. I caught the fellow on the way out and told him to go back and ask for a set of lights, or light mediums for his guitar. Reason being the heavier strings would drastically have changed his string height, as well as lifting the bridge right off of his lovely little Ovation due to the increase in tension.
So the right strings are always important on an electric and an acoustic guitar, and yes...even on a Bass. Longer scale basses like the Fender Jazz and Precision, require a longer scale set. They are usually a dollar or two more, but get the right strings for your bass. That is important.
Most modern bass guitars utilize a 'dual action' truss rod. This is like two rods in one. These are used on instruments with wider and thicker fretboards and are well known to bass players because of the longer scale of the instrument. They work quite similar to single action truss rods, but require very little adjustment comparatively to the others.
So keep all of these things in mind whenever you are setting the 'action' on your guitar.
An old fellow at one of the places I used to frequent when I was a kid once told me.....the action on your guitar should be as close to the frets as you can get it without a rattle or a buzz. If you get a rattle or a buzz, raise the bridge! Wise words! And really, that is the way it is.
We all have different tastes, feels and sounds. But really, string height should be what you want, and what you feel is right. There are things to watch out for with super-low action, but that will be another story. Rock on!!

Brett McNaueal

Truss Rod Adjustments

This can be a complex issue, but really doesn't have to be. The most important thing to remember is that you want to see a slight relief in the neck. That is looking down the headstock toward the 12th fret. You want to see a slight 'dip' in the neck between the 4th and the 9th frets. This maintains fret clearance to the 12th fret. After that the bridge takes over and maintains clearance up scale. How much relief? Depends on the type of the guitar, the wood the neck and fretboard is made from, string gauge, and a whole lot of other things. Acoustics are different from electrics and require slightly more relief to allow for string clearance on the first three frets.

When storing guitars, it's always a good idea to back off the string tension a couple of tones to allow the truss rod to rest. Adjustments to the truss rod should only be made when they are really necessary. (i.e. fret buzz, resetting action, or intonation problems)

Hope this helps.

Cheers!

Brett

Storing Your Guitar

It is always a good idea to back off the string tension on guitars that are going to be stored. This allows the truss rod to rest, and you can rest assured the guitar will perform properly when you decide to tune it back up and use it again.

If the bridge is lifting on a guitar, especially a twelve string, that is usually the cause. Always a good idea to tune a 12 string down a full tone and use a capo for performance. You will find the guitar easier to play, your strings will last longer and sound better as well. And don't let anyone sell you medium gauge strings for and acoustic. They simply cause too much strain on the body, the soundboard, bracing and the binding. When this stuff comes apart, it's only a matter of time before the bridge plate lets go. There is just nothing left to hold it in place.

Also, humidify these instruments. A solid wood top guitar needs constant humidity. This should run between 38 and 45%. That sounds like a lot, but you have to remember our humidity usually runs at about 50% in the summer and about 30 in the winter. If you have air conditioning at home, be careful with that. Any air conditioner is also a de-humidifier. They all remove humidity from the air before cooling it. It just makes it that much easier to cool. This then means that if you run the air conditioning all summer long, your humidity level should be a concern here.

You mention the Gretsch guitar. I believe that one is the Electromatic. I really wouldn't worry too much about this guitar. As I mentioned prior, loosen the strings and relax the truss rod. By doing so you are also taking undue tension off of the soundboard. Archtops should be treated a little different than the others. They are a little more delicate. Still, the Gretsch is a laminated maple top, and that is tough stuff.

Hope this helps!

Cheers!