A customer’s email prompted today’s post. He’s not the first person who’s mentioned issues with 6-screw tremolos, so I thought I’d write an article and append it one of our other technical docs here.
Fender’s traditional 6-screw floating tremolo is a good bridge, though it has a reputation for not staying in tune. While it’s not realistic to expect this bridge to stay in tune as well as a double-locking unit, such as a Floyd Rose, it certainly can be made to stay in tune fairly well if a few tricks are employed.
By the way, this is a floating tremolo, or was originally designed to be so, though obviously it doesn’t have to be set up this way. The floating aspect has been disputed by some, but Leo Fender’s original patent drawing is clear.
The thing that causes tuning instability is friction. Any friction – whether friction in the strings’ paths, or mechanical friction in the system itself – will negatively affect the trem’s ability to stay in tune. Actually, what you’re really trying to do is to get everything that moves during the trem’s operation to return to the same “resting” position, over and over. The better you can get everything to return to the same position, the better your guitar will stay in tune.
So, what is “everything that moves”?
- The tremolo itself
- The tuners (possibly)
- The strings
The first thing is to make sure that the tremolo moves freely in the body, with no mechanical restriction. To do this, remove the springs in the back of the guitar. Then loosen the six screws on the front that anchor the trem to the body, until there are visible gaps between the undersides of the screw heads, and the top of the plate. Better yet, make the gap at least 1/16″ or 2mm. Now, slowly and carefully, screw in either one of the outside screws while you watch the rear edge of the plate. As soon as you see the slightest sign of the top plate’s rear edge lifting away from the top of the guitar body, stop, then back the screw off 1/4 turn. Do the same thing with the other outside screw (the four interior screws should still have gaps under their heads).
This is the optimal position for the outside screws. They should not push down on the front edge of the trem at all, but should be so close to the top plate that the plate’s front edge essentially cannot lift away from the body. In this way, the screws won’t cause any binding of the plate, but neither will they allow it to lift away from the guitar. It’s captured, but with free range of motion.
Now, physically move the trem up and down so that you hear it banging between two stops: In the down position, it should be stopped by the underside of the plate hitting the top of the guitar, and in the up position, it should be stopped when the tremolo block hits the rear wall on the inside of the cavity. Between these two stops there should be absolutely no friction that you can discern. The trem should move completely freely between the stops, banging into the wood cleanly at either end of its travel.
Assuming that the trem moves freely, you’ll lower the four interior screws so that the gaps between the undersides of their heads and the top plate is roughly the same as the thickness of your low-E string.
If the trem doesn’t move freely, then figure out what’s causing it to bind and fix it. Could be that the tremolo block is rubbing against the inside of the cavity. Whatever the source of the binding, you have to find it and fix it, or else your trem will never stay in tune.
Now, have a look at your saddles. Saddles should be smooth where the strings pass over them. If they have grooves or ridges in this area, try to smooth them with files or abrasives, or replace them. Smooth, hard saddles will reduce friction and help to alleviate tuning instability.
If your tuners are slipping, then you’ll have tuning instability forever and ever, amen. This stands to reason, right? They need to be tight and right, or they need to be replaced.
Also, good stringing and tuning habits are essential. There are lots of articles on stringing, so we won’t cover that here. We personally don’t buy into the notion that strings need to be locked to the tuner post by bending the loose string end back on itself, whatever others might have to say about it. And of course, this isn’t possible anyway if your tuners are of the Kluson Safe-T-Post style that Fender used on the original guitars, and that they continue to use on the Reissues (these are the tuners with the hole in the center of the post, where the string end is inserted into the hole before winding the string on). But one rule of thumb is to have nice, even wraps of the string down the post. Don’t let the strings wrap up the post, and don’t let the wraps overlap each other haphazardly.
And tune up to pitch, not down to pitch. This is less of an issue with today’s higher-precision machines than it used to be with older tuners, but it’s still good practice. Tuning up to pitch means that you’ve taken the lash out of the gears, so they’re less likely to slip when you tug on the string.
And now we get to the heart of the matter. Keep in mind that the strings are physically changing in length as you use the tremolo, getting longer when you pull up and shorter when you push down, so they’re sliding past objects that they’re in contact with, such as saddles, nut slots, and string trees. The goal is to keep contact and friction to a minimum.
A properly-cut nut will have slots that are wider than the diameters of the strings. If you have a .010″ high-E string, and the high-E slot in the nut is .010″, then you have contact all the way around the bottom half of the string. On the other hand, if the slot in the nut is wider, say .012″, then you only have contact on the bottom of the string:
Less friction is what we want, so make sure that none of the strings are binding in the slots. If you hear a “tink” “tink” when you’re tuning a string, you’ve got friction. Make sure that the slots are wider than the strings, and also, lubricate the nut slots. There are companies out there that market products for this, but we find graphite powder the easiest to apply, and it works great! You can find small tubes of it at Lowes or Home Depot, in the area where they make keys (it’s sold as a lock lubricant, and is very inexpensive). Just put a little in each nut slot, then put the string in the slot, and blow off the excess. Instant slippery-ness!
String trees pose another problem. The reason they’re used at all is that on Fender guitars, the B and high-E strings have a very shallow angle where they pass through the nut. There’s not much downforce over the nut at all, and so the strings ring when played in their open positions. Very light finger pressure on these strings between the nut and the tuner posts will usually be sufficient to dampen this extraneous vibration and stop the ringing, but instead many guitars have a string tree (or two) that put much more downforce on the strings than is needed to stop the ringing, and this is a significant source of friction.
Ultimately you’d like to have string trees that apply only enough downward pressure to stop the ringing, and no more. Tom Anderson used to provide a cool solution with a height-adjustable string tree, with a spring underneath it (don’t know if they still use this design). You could screw it down just enough to stop the ringing, and so it exerted no more force on the string than was necessary, thereby minimizing friction.
On those guitars that come with the string tree screwed right down against the face of the headstock, you can install a spacer (Fender PN 002-0423-000) between the string tree and the headstock. This raises the tree up and substantially lessens the angles where the strings “break” over the nut and underneath the string tree. This will substantially reduce friction.
Further, you can polish the undersides of the tree, removing any burrs or sharp edges, and making the area where the strings contact as smooth as possible. This can be done with files, sandpaper, a Dremel tool with burrs and stones, polishing compound, etc. The smoother the better. Or, there are aftermarket string trees that are designed to alleviate friction, such as those from Graph Tech.
Finally, there are tuners with height-adjustable posts, where you can lower the post heights for the B and high-E strings in an attempt to create the downforce required over the nut, allowing you to get rid of the string trees altogether. Alternately, you can make a wedge that fits between the tuners and the back of the headstock, with the thinner end (.020″ or so) at the low-E tuner, and the thicker end (.100″ or so) at the high-E tuner. This accomplishes the same thing as the adjustable-height tuners. We’ve seen these made of wood, and they were actually available in the mid ’90s from Wilkinson, made of aluminum.
The bottom line: String trees create friction, and less is better. So smooth them; lift them; whatever you can do to create the smallest angles in the string and still stop the ringing. Or, get rid of them entirely.
Do These Things
…and you will alleviate tuning instability to a great degree. These trems can be made to stay in tune much better than their reputation would have you believe.