# Action limitations? An exercise in buzz minutia.

I've created a short and long version of my question in the interest of quick answers vs. heavily detailed responses. I appreciate any response.

Short Version:
I've leveled a guitar with no truss rod. Up to tension, the frets are dead level. Say you've refretted a Martin with no truss rod, and you have the same constraints, dead level, 53-12 strings. Do you have to set the action a little higher due to the lack of relief to avoid buzz? Or is there a repeatable, predictable way to put some relief into the frets? How low do you go on a dead flat fretboard? What do you say to customers is "low action without buzz"?

Long Version: I've read Frank's buzz bible, so I've read about diagnosing it, but I am working on a guitar here which has buzzing issues. It's very light buzzing, but it's pretty much even all the way across the board. My question goes to people out there who have dealt with picky customers who say the words "Lowest action without buzzing". How low is that, measuring at the 12th?

At a certain action, I start to question how low you can go without the buzz of a simple rotating string. I'm looking for concrete answers now instead of just assuming that I messed up on a process, or that a customer can insist that they've got a guitar with lower action.

The question ponders how low you can go without any relief? The guitar I'm working on has been made dead level with a 24.5" scale length, and I'm wondering if anyone has documented either personally or otherwise, the limitations of low action in various environments. Eg. various string tensions, amounts of relief, scale length, and so on. The reason I ask is because some times guitars buzz in certain areas, like the D and G string, but not others.

Here's the notes on the guitar in question.

•  Frets have been leveled, and from the first fret to the 18th, it's dead level, confirmed with a .0015 feeler and a precision straightedge.
• 16" radius, used a 16" stewmac radius beam to level the frets with 600 grit PSA, so I wasn't hogging off material.
• They are all crowned (no flat tops), and have been polished up to 1500 grit then a dremel/jeweler's rouge buff.
• There is no truss rod in this guitar.
• The action at the 12th fret on the low E is 3/32nds, and the High E is 2/32nds.
• There is no open string buzz, so the nut is not an issue.
The only way to test this out is with other guitars of the same specs, and spend time experimenting. I'd love to do, but don't have the available instruments to try it on. I'd like to be able to have the background knowledge with a bunch of other guitars, but I don't, so I go to the board full of experience.

Any help would be great. I deal with this occasionally, and I need to be able to say to myself, "This is just the limits" or "I've done something wrong, this is how to fix it". I'd love to talk to someone on the phone, so if you're willing, send me a message and I'll give you my phone number.

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### Replies to This Discussion

Jeremy, you have left out one factor- the factor that makes it impossible to answer your questions definitively. That is, of course, the player. I have set up several guitars for Martin Guitar clinician George Sabolick with insanely low action and virtually no relief. I was not able to play his guitars at all without getting buzz, no matter how softly I tried. He is able to play with decent volume absolutely cleanly. Now, mind you, he's not playing like Martin Simpson. The point is the player is a huge factor.

6/64 and 4/64 is standard low action for me ("Six and four and out the door!"). If it buzzes it needs a tiny bit of relief, which in this case I'm afraid means refretting. You haven't said but I assume this is an ebony fretboard. You'll have to squish the tangs so there's less wedging effect.
Phenolic fretboard, actually.

The player being me, mainly. I am the tester of said guitars, so I'm looking for a middle ground of soft player low action, and sitar-less strumming height. I suppose I should ask for more of a middle ground of action, or barring picky players who know measurements in 64ths, what do you set them at for strummers? And what do you set it at for George Sabolick?

Knowledge is power, as is electricity.
I don't want to hijack here, but I'm following this post in the hope of learing a lot about this subject: With the re-frets I've done upto now on necks without an adjustable trussrod I've always managed to luckout, and they've always turned out well. But I think every time before I start: What if it goes bad? Is it even possible to achieve a super low action without being able to fine tune the relief with the trussrod? Or is it possible with expert fretting and a lot of guesswork, based on a lot of fretjobs and many years of experience?
Sometime in the next week or two, I have a '74 Martin D-28 in for major surgery: Quite severe top belly, neck reset, and then a complete refret to finish the job. It has no adjustable trussrod, just the square tube neck reinforcment, and I don't want to screw up such a nice guitar :-)

Grahame
Good to know I'm not alone here, Grahame. Looking forward to some good discussion.

I am hoping to rule out the guesswork and get down to the real manufacturing style answers; something repeatable, predictable, and therefore profitable. The more direction I have, and the more I can learn from others experiences means I don't have to butcher a 2000 dollar guitar just to test if a pre-bent neck can give me relief when I let it go.

-Jeremy
I thought I'd bump this one up, as I'm really interested in learning from some of the very experienced repairmen that hang out here.
I'm surprised that this subject hasn't inspired more discussion up to now. Is it really so that, in the case of a neck without an adjustable trussrod, the only way of controlling neck relief is with the frets? Could you also sand a bit of relief into the neck before you fret? And is it just a matter of "gestimation" and previous experience to get it right first time? Or can you measure and calculate to arrive at a predictable result, without having to refret 2 or 3 times to get the relief right?
The thought of refretting the '74 Martin that's coming in next week is making me a bit nervous :-) So many questions, so few answers.......I don't wanna screw it up, the customer loves that Martin more than his wife (knowing his wife, I can relate to that, but lets not go there :-))

Best

Grahame
I've been taking readings with a dial indicator tool, strings on/off, which gives me an idea of what string tension does to the neck.
that's an interesting idea, then at least you can get an idea of how flexible the neck is.
One day when I'm feeling extravagant I'll get this:
http://www.stewmac.com/shop/Tools/Special_tools_for:_Neck,_fingerbo...
On the other hand: over €420 + shipping and customs duty, then maybe not......
Sweetheart, where did you put the Visa card? (insert evil grin here)

Best

Grahame
We actually made our own Erlewine neck jig. Solid backing with some adjustable threaded inserts. Clamp the guitar down, tune to pitch, adjust the 5 threaded inserts until they are just barely touching the back of the neck, and when the strings are removed, the neck stays in the same position it was when strings were on it in tension. Works great for making the frets dead level, and probably cost about 30-50 dollars to make, that being said, we don't have the dial indicators on it. Though, I do use a dial indicator to see how much the neck bends under tension.

I might be able to take some pictures when I get back to the shop on monday.

-Jeremy
Phenolic! The phenolic fretboards are the reason Martin went to a 2-way truss rod.

The setup for George was 4/64 bass E, 3/64 treble E.
If I have a nonadjustable trussrod neck that needs relief, and the frets allow, I clamp the guitar down at the heel, put a block under the neck where I'd like the center of my relief and then using another clamp, pull the peghead down until I have backbow that equals the relief I want. Then I level, recrown, etc. When the clamps are released the neck has the bow I desired( which depends on the player)
I use the way martin Guitar sets up their guitars.

I support the guitar at the first fret and the end of the guitar. I then use lead weights 12 lbs at the sound hole as close to the end of the guitar as possible.

I made two pieces of lead with a hole in one end and put a flexible plastic wire of strong cloth string between them so when you lay the string on the guitar the weights hang down the sides of the guitar,

The weight makes the guitar think it has strings tuned to pitch on it.

I then if it has a adjustable truss rod i level the frets then I use a blue felt marker to mark the top of each fret then I use a sand paper on a straight stick and level the tops until each fret has been marked or some blue is gone from the fret. You know it is dead level at that point.

I have never needed to put a relief in the middle but you could have your leveling stick with the relief to it before the sandpaper is applied to it.

You will find that all new guitars are not level at the frets.

I then give a small relief to the middle of the neck.

I find that if holding the pick at a small angle the the strings and vertical from the strings you get the best sound and if the pick is laid flat to the strings it will buss as the strings are plucked up and down and if the strings are plucked with the pick in a vertical position the strings will vibrate in a side ways.

I am available for a phone call is any one wants. I am in Oregon

541 567 3226

Ron