Acoustic saddle adjustment

chris45 · February 2022

My Furch acoustic is getting some extended playing time after being neglected for a year or 2. I'm thinking of shaving down the saddle as the height of the low E at the 12th fret is 3.5mm which seems too high, and the high E is 2mm.
Does this seem reasonable, and is it something an amateur can do?

drofluf · February 2022

It can, but with care and patience. Remember to lower the action by 1mm you’ll need to take 2mm off the saddle. It also sounds like you need to take more off the bass side than on the treble that complicates things a little.

Edit ignore the bit above

But, before you attack the saddle are the other aspects of the setup - nut slots and relief OK?

ICBM · February 2022

drofluf said:

It can, but with care and patience. Remember to lower the action by 1mm you’ll need to take 2mm off the saddle.

No!

You need to take about 1.5mm off the saddle.

It's more complicated than simple geometry would indicate, because lowering the saddle reduces the 'turning moment' of the strings around the top of the saddle where the break point is, which reduces the upwards force on the bridge and the top will settle down slightly, lowering the whole bridge.

I was caught out by that several times early on when I was doing repairs and wondered why my careful measurements resulted in a too-low action and buzzing - and a choice between either shimming or replacing the saddle, neither being ideal when you've just been asked to lower the action.

It's always better to need to take off a tiny bit more at a second attempt than to overdo it the first time.

drofluf said:

It also sounds like you need to take more off the bass side than on the treble that complicates things a little.

A little, but only in the sense that you need to cut at an angle. I would aim for 1.75mm (high E) and 2.5mm (low E), so I would take off about 0.4 mm on the treble side and 1.5mm on the bass.

The way I do it is to hold the saddle upside down in a bench vice with just the right amount sticking up above the jaws, easily measured using a vernier caliper - then smoothly file off the excess down to the jaws. That ensures the cut is straight and that you can't go too far. It can take some time and fiddling to get the heights right but it then makes the actual cut very straightforward.

Mellish · February 2022

@chris45 ; - if you've never done this before, I'd suggest you buy another saddle and practice on that. This way you stand a better chance of not ruining your guitar's original saddle

drofluf · February 2022

@ICBM post corrected. Thanks! I was passing on some received wisdom from a mandolin forum - where the shorter scale might mean my statement was closed to being correct.

ElectricXII · February 2022

It's doable by an amateur. I just lowered the saddle height of my J-35 today. My advice would be to take your time, sand, refit and check, then sand again if needed, rather than try to take it all off in one go.

danishbacon · February 2022

A capo on first fret will also do wonders for the loosen/pins off/saddle out/saddle back/pins back/tune up dance.

Andyjr1515 · February 2022

ICBM said:

drofluf said:

It can, but with care and patience. Remember to lower the action by 1mm you’ll need to take 2mm off the saddle.

No!

You need to take about 1.5mm off the saddle.

It's more complicated than simple geometry would indicate, because lowering the saddle reduces the 'turning moment' of the strings around the top of the saddle where the break point is, which reduces the upwards force on the bridge and the top will settle down slightly, lowering the whole bridge.

I was caught out by that several times early on when I was doing repairs and wondered why my careful measurements resulted in a too-low action and buzzing - and a choice between either shimming or replacing the saddle, neither being ideal when you've just been asked to lower the action.

It's always better to need to take off a tiny bit more at a second attempt than to overdo it the first time.

Absolutely this! I came across the same thing when I was trying to set up the guitar bouzouki I made a year or so ago. It stumped me for ages - I even assumed that my braces were failing. That or my mind - until I sussed it.

Wisdom duly awarded, @ICBM

chris45 · February 2022

Thanks for all comments and yes @drofluf I am happy with neck relief and nut setup. Won't attempt this until next week as I have some "real life" higher priorities but am ordering a desk vice. Will take before and after pictures.

DavidR · March 2022

Very do'able by an amateur and I have done it several times over the years. I'm always reassured that a saddle is such a basic bit of a guitar and that I can buy another one off Amazon if I mess it up - although I never have done. I usually use the opportunity to change to bone.

Use a sanding block so base of saddle stays perfectly flat and you don't end up with a saddle which rocks and makes poor contact. Draw a line on saddle with a pencil of where you want to sand down to. As others have mentioned, cautious increments if you're nervous.

On the same basis as an amateur you can do nut adjustments as you get more competent, but they're a bit more tricky and you'll need specialist nut files.

Good Luck!

chris45 · March 2022

Done and very happy with the result. I tried to take photos of the string height with a gauge but it was beyond my phone to get decent results. However attached are before and after pictures of the saddle and you can see the change in the profile. It has really improved the playing experience:

sev112 · March 2022

The trouble with lowering the saddle is that the break angle of the strings gets significantly reduced. I’ve seen various luthiers and techs saw/cut/form a vertical slot in the peg hole to steepen that angle again after

BillDL · March 2022

My preferred method of accurately sanding down saddles is with an improvised tool that acts as a depth stop. I have an old lightweight aluminium hobbyists vice with smooth flat jaws that are the same length as most acoustic saddles. It doesn't open very far, but I don't need it to. It used to have the G-Clamp part to secure to a desk or bench, but I sawed that off. As long as I carefully check how much of the bottom of the saddle I leave protruding from the jaws and tighten the jaws firmly, I can hold the vice with the jaws downwards towards sandpaper on a flat desk and just sand the excess off the saddle until the vice jaws scrape on the sandpaper. I don't have to worry too much about keeping it vertical or applying too much pressure in any one area. Quick, accurate, and completely improvised like most of the tools I have used for the wrong purpose over the years.

bertie · March 2022

I got some bone ones made to spec for my little TW parlor - about £15 IIRC I got 2 done with 1.5mm difference

cant remember off the top of my head.......pretty sure Ive still got the packaging tho

TheMadMick · March 2022

I use a very similar technique but I use a file if there's quite a bit to come off. However, I always draw file it to finish with before taking it out of the vice and check the bottom against an accurate straight edge to ensure the pick up gets all the signal from the saddle.

TheMadMick · March 2022

sev112 said:

The trouble with lowering the saddle is that the break angle of the strings gets significantly reduced. I’ve seen various luthiers and techs saw/cut/form a vertical slot in the peg hole to steepen that angle again after

If you look closely at the B and e strings you will see that's already been done.

sev112 · March 2022

https://www.youtube.com/watch?v=LbnykeDM6s8

29 mins onwards for a very nice tool /jig for getting a perfectly flat base

chris45 · March 2022

TheMadMick said:

sev112 said:

The trouble with lowering the saddle is that the break angle of the strings gets significantly reduced. I’ve seen various luthiers and techs saw/cut/form a vertical slot in the peg hole to steepen that angle again after

If you look closely at the B and e strings you will see that's already been done.

These are factory diagonal slots cut into the bridge for each string; the higher (pitch) strings have slots that are furthest from the vertical which makes them extend out further from under the pins and so they are easier to see.

chris45 · March 2022

sev112 said:

https://www.youtube.com/watch?v=LbnykeDM6s8

29 mins onwards for a very nice tool /jig for getting a perfectly flat base

It looks a great piece of kit although it is £150 from StewMac so probably only from full time techs!

guitarjack66 · March 2022

I am going to try this but I have no tools to speak of. I've seen it done where you simply draw a line using a rule across the bottom of the saddle. You than sit it on a base of sandpaper and simply rub it straight until it reaches the line you've made. Then you put it in the guitar and adjust as needed. Sound ok?

sev112 · March 2022

Yes, but you also can end up sanding the tips off your fingers ! Hence some kind of tool helps to grip, but then you have the problem of keeping the scrapes parallel to the line you draw.

But yes, take it really easy, slow and make sure you get a full stroke with constant force applied - it is REALLY easy to take the load off at the end of the stroke, which leads to a convex aurface, and once you are in that territory it can be a nightmare trying to get back to planar.

but lots and lots of people have been doing it as you say for decades so it’s perfectly possible and viable - hope it goes well

Mellish · March 2022

Jack, I'd say don't do it the sandpaper way. If you've never done it before, it's easy to screw it up this way. If you have a vice, use that. Read again the instructions given by ICBM

Tannin · March 2022

I have got some good tips from this thread which I plan, later on today, to apply to my upside-down leftie. It was much too high when I got it, mostly because of neck bow. I've adjusted that via the truss rod down to 2.8mm and 2.5mm at 0.3mm relief, and I can sneak that down a fraction further, but it needs a little off the saddle too.

Usually I take things to a luthier, partly because my other guitars are expensive and precious, partly because seeing me darkening the door of his workshop probably functions as a gentle reminder that he has my order for a new guitar on his waiting list, but the leftie is only a cheap one so I'll give it a crack.

I don't have a suitable vice, but I expect that I can find a couple of bits of something to clamp it between with G clamps - a couple of steel rulers or similar. That ought to do the trick.

It wants to come down about 0.5mm, maybe slightly more on the treble side, so I'll aim to take 0.5mm off the saddle, gain maybe 0.2mm from a final truss rod tweak, and see how it goes from there.

(All of this is assuming that I can get the saddle out without damaging the bridge if it's a tight fit. First things first!)

BillDL · March 2022

Tannin said:

All of this is assuming that I can get the saddle out without damaging the bridge if it's a tight fit. First things first!

Yes indeed, that can be problematic before you even start. Some of the stainless steel fretboard protectors that you use while polishing frets have a long enough slot for an acoustic saddle to come up through. If you have to use end nippers to pull the saddle (not recommended), the fretboard protector can help you avoid chip-out of the bridge if you hold it down at the side you are pulling first. In general you should be able to just lift the weight of the guitar by the protruding saddle, but still be able to lift it out without tools from one side. If there is an under-saddle transducer strip, the saddle has to be slightly less tight fitting.

Mellish · March 2022

@Tannin, ; - grab the saddle between thumb and index and pull up. That might be all that's needed to get it out. If that fails, and you opt for pliers, be careful to pull straight up, not towards the neck or lower bout. I'm sure you know this but it's as well to say

bertie · March 2022

needle nose pliers and a cotton cloth/hanky, I grip the end "longways" and rock/pivot the pliers on my other hand which is on the upper or lower bout, and gently to pop an end "out" from there you can use your fingers

Tannin · March 2022

Tannin said:

... later on today ...

I got busy.

.... er .... Tomorrow?

Nope. We are going to Hobart shopping.

How about Thursday?

Er .... Would you believe Friday?

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Acoustic saddle adjustment

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