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Worked all night again and just got home. We are so busy these days many have to wait 6 months or more to get in with us unless they are a gigging musician we prioritize them and for our famous clients we close down and lock the doors and give them personal attention.

Worked on a Floyd equipped shredder and wanted to show folks something super useful to us and invented by David Collins my business partner.

It measures the depth of nut slots in respect to frets one and two.

As you know I've been talking here till I'm blue in the face (better than the alternative) about nuts slots, cutting them lower then you think you can and why, intonation improvement that in our considerable experience on a steel string eliminates any need for nut compensation. By the way Collins is Feiten trained, used to teach nut compensation and found a better way AGAIN... for steel string acoustic instruments that someone actually plays and they are not wall hangers or historic relics or classical instruments with nylon strings and a tradition of higher action than steel strings.

So in the pic with the Martin OOO-28 we see the tool and I've just cut this slot to where I like it in respect to frets one and two. I've brought this up before and amazed some folks but a well cut nut slot for a treble string may be lower than the first fret AND any zero fret would be if it had a zero fret. You can see I am a thou lower here and for this .011 string, Custom lights for an older guy with arthritis this guitar will play like butter. He has a gig tonight so does the other guitar player with the Ibanez.

If I placed the tool on a surface plate and pressed down it would read zero FYI.

Moving on the Floyd Ibanez shredder likes very low nut slots too and that's what shredding is speed playing and low action and alternate tunings such as the low E tuned to C are common and this guitar will have to do those things perfectly.

Chris Pyle knows and shredders have been a big part of his work too. You might like this tool Chris it makes Floyd nuts way easier to lower.

On a Floyd nut we don't individually cut the slots because it's a prefab steel nut assembly. It's possible to cut the slots individually but a pain in and ass and a time suck. We have done it for an A-lister but he gets special treatment.

I remove the nut and install two of the screws as handles for the belt sander as I mill the bottom of the nut down, measure and mill, measure and mill. The cup of water is to drop it into because it gets too hot to hold. You can see in the pics that it started out .018" higher than fret one and that's terrible. This thing would not play in tune there was so very much string stretch from fretting notes.

Also a note on why we mill the nut down and not the wood in the nut channel. We do not want to weaken the neck at the headstock joint by digging the nut channel deeper. In this real life example that would have been .018" of material removal from the neck and that would weaken it. Other Luthiers may mill the neck instead but we don't like this.

The pics tell the story of the bottom of the nut assembly coming down on the belt sander and you can see my results in the end. I am below the height of the first fret, again and this guitar will play super easy now. When I fret between the second and third and hold and pulse the string over the 1st it still "tinks" indicating it's not laying or in contact with the fret.

As I've offered here many times strings arc out of these slots, off saddles etc. and that's how it's possible to have a slot lower than the next fret and this is a perfect illustration of just that.

How low do we cut them. It's difficult to measure but for a high e .010 we think we are below .0005" when fretting between the 2nd and 3rd. Dave goes lower than I do he is a young guy at 46 and can still see... Each progressively more massive string gets cut higher.

Again the value of this is improved intonation on fretted notes for frets 1 - 6ish. Less string stretch, etc. AND MUCH easier to play.

It's also one of the few things you can do for your clients that they will notice at once when they play especially barring the first fret. They look up at us while trying it and smile and we love it.

And a pic of my bench in Ann Arbor at 3:00 AM this morning.

Interesting, Dave is an inventive guy. Disregarding locking nuts, are you using that to cut nut slots without installing strings or is it just for doing the measurements?


Steve

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Steve Smith
"Music is what feelings sound like"

Worth it. Must fabricate.

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"Act your age, not your shoe size" - Prince

Hesh--

Could you show a photo of the underside of the tool that references off the first two frets? I figure the plunger for the dial indicator has been thinned down to a blade, but it would be great to see a photo of it. Thanks.

Hey Steve!

I like it for Floyds with no strings to do the hold at fretting between the 2nd and 3rd thing with. If I set the high e for -.001" as it is and progressively go to .005" for the low e the nut on a Floyd always comes out perfect and super low.

I'm using on the Martin to further illustrate how a slot can be lower than the first fret and not be too low.

We also use this tool for triage because I went on the nut (pardon the pun) when there are low nut slots and I have to get out the light cured dental fillings and the client doesn't get charged. If we add the value of a semi permanent nut slot fix I want our shop compensated for it so we check nut slots when instrument come in and use this tool to prove what we see to the client.

It's also a very good teaching tool and if you remember Dave has taught at the Galloup school so he's always in teach mode too.

Sure the next time, maybe Sunday.... I'm in the city I'll get some pics and use the blade has been thinned to .007: thick.

It's a very easy tool to make too and you just need access to a surface plate to dial it in.

Thought so I knew you would see the value of this tool right away and thought of ya Chris.

That is a neat dial caliper. Looks ideal for the application. I must fabricate one too.

Very cool, glad you like it Barry. They are very useful to have around and lets us quantify what we think we see.

If you saw my post to our friend Don I'll get more pics Sunday and the blade is .007" thick.

This is a fantastic thread, Hesh, thanks for sharing with us!

Dave's tool is brilliant, which is not surprising.

I also want to make one and would love to see photos of the underside.

You are very welcome Leo and I'll get better pics this Sunday when I am back at work.

In case anyone else is interested, I've just found that you can buy pre-made blade tips for dial indicators.



https://www.aliexpress.com/item/1005004247155001.html?spm=a2g0o.order_list.0.0.a1401802Idxscd

I don't vouch for any particular ones, but grinding down something like the ones linked above to 0.007" from 0.015" seems much easier than making a blade tip from scratch.

Good catch Leo, I was going to cut up a feeler gauge.

_________________
Steve Smith
"Music is what feelings sound like"

This, by the way, is the OLF at its best: Extremely helpful information, built upon by others with related helpful information, to make a gumbo of knowledge that advances the craft. Thanks!

I think it's simpler to use a thin straightedge (a 6" feeler gauge works well) to span from the 2nd fret to the nut slot. You can measure the gap at the first fret with feeler gauges. When a .0005 feeler gauge just drags through the 1st fret gap, you're at the same point that you'd get to with a .001" reading on your dial indicator.

Hesh, I LOVE this kind of tool! Can't wait to see the underside pics so I can make one too!


Pierre
Guitares Torvisse

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Pierre Castonguay

Reread your post, Hesh. I missed that you are setting the slots below the level of the frets. A shim under the straight edge at the 2nd fret would make that easy to measure. Obviously the shape of the nut slot determines whether they can be cut that low. If the final break angle is slight, there is little upward arc of the string as it leaves the nut.

I use feeler gauge straightedges that correspond to the thickness of the string because the rounded edge of the feeler gauge sits in the slot the same way a string would. What is the profile of your indicator blade?

Thanks Eric good suggestions. The blade that sits in the slot is rounded too I think but will know more tomorrow I have another pile of guitars to go fix on a Sunday now....

Thanks for the ideas on measuring I will have to give that a try.

And you are absolutely correct and good point too that the break angle as well as the string stiffness are what determines our arc out of the slot and off a saddle crown too for that matter.

I used to cut the head stock set-back angle in half as my nut slot angle but now my approach since I do so very many in a single day is to cut the angle that just feels right to me and it's the same on every instrument. I cut rounded slots too increasing the angle of the file on the back side of the slot being careful not to stub the file in the head stock...;(

I don't use this tool for my work generally except on Floyd Rose things.... and I only used it here to illustrate the concept of a steel string slot cut below the height of the first fret. It demonstrates it nicely and clearly.

Great suggestions Eric, thank You.

Thanks Don, I love gumbo, dang it. Wait that was Gumby...

Very cool and I did not know these were available! Thanks Leo!!!

Found one more pic on my phone of the tool that Dave Collins came up with. As always please give Dave and anyone credit for his/her/their efforts if you ever share any of this or someone's Lutherie IP (intellectual property), thanks.

This tool is over 20 years old and in commercial use all of that time so you can see the wear on it.

The proper name for an indicator tip is probe.
And some old school guys call them "the pecker".

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"Act your age, not your shoe size" - Prince

Oh, great. Once you start calling it a pecker, Hesh won’t be able to use it without giggling.

I have a question , Hesh. In the pics at the top I see you’re using this tool with the strings off. In the pic of the underside it appears to be a thin edge. I presume this is because you may need to use it with strings on. Is that right?

When I use other tools like this, for example the relief gauge from SM, it’s easy to change the reading when leaning the tool side to side.

I guess if I never planned to use it with strings on I could make the surface wider to avoid being able to tilt L/R.


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The thin edge is so it will fit in the nut slot.

Edit: ignore this, I misunderstood the question.


Steve

_________________
Steve Smith
"Music is what feelings sound like"