Review of new stewmac nut slotting gauge

[BlueMountain]

I've always found it difficult to do a really accurate set-up at the nut because I find it difficult to use feeler gauges. Even on the outside strings, I find it difficult to tell if the string is just touching the gauge or if the gauge is lifting up the string a bit. The inside strings are even harder to do, given that I have to wear magnifying loupes to see the space between the string and the first fret clearly, and I'm peering under the outside strings. The result is that my nut filing has been adequate, but not as good as it could be, and I tend to err on the side of caution, rather than cut too low and have to make a new nut.

Thus, when I saw the new Nut Slotting Gauge on the cover of the Stewart-Macdonald catalog, I read the ad carefully. It costs over $60 with shipping. That's a lot of money. Would I use it? Would it be worth it? Then I thought of how hard it was to cut the slots to the proper depth and decided to buy it. ttp://www.stewmac.com/shop/Tools/Special_tools_for:_Nuts_and_saddles/Nut_Slotting_Gauge.html

It arrived yesterday, a neat little hunk of milled brass with a dial caliper that sticks through and locks in place with a screw and knob. The caliper foot has a brass foot attached to the end of it to balance on the string being measured.

What I found was that it worked great once I figured out how to use it. I found the directions (available at the link above) odd and inappropriate for mandolins. Here's what worked for me. I assume that a string needs to be no higher above the first fret when the string is open than it is above the second fret when I'm holding down the string at the first fret or the string at the third fret when I'm holding down the string at the second fret, etc. If the string plays cleanly when I'm holding it down at a fret, then it is high enough. It doesn't need to be any higher on an open string.

Here's my process. (The photos that follow--taken one-handed) show the measuring being done on both strings in a course at the same time. In practice, I use a Stew-Mac String Lifter http://www.stewmac.com/shop....er.html (http://www.stewmac.com/shop/Tools/Special_tools_for:_Nuts_and_saddles/String_Lifter.html) to lift one of the strings to the side or off the nut entirely. I took the photos before I'd figured this out.)

Step 1: Place the Gauge over a string at the 2nd fret. With two fingers, hold down the string at the nut side of the first fret and bridge side of the third fret. With the other hand, rotate the caliper face until zero is in line with the caliper needle.

[BlueMountain]

Step 2: Remove the finger holding down the string at the third fret, but keep on holding the string down at the first fret. The string will lift to its usual height when it is fretted, and that height will be seen on the gauge. In this photo, the height looks like 0.011 inches, but I was taking photos with one hand. Actually, the mandolin has low strings and good frets, and I found on single strings that the space tended to be very close to 0.007 inches--less than the thickness of an E string. That's all the height you need at the first fret, though even as much as 0.010 at the first fret is quite acceptable, compared to the usual set-up.

[BlueMountain]

Step 3: Now move the gauge down to the first fret. Press on the string on the bridge side of the second fret. Zero the caliper. Don't try to press on the string on the nut side of the fret (as recommended in the StewMac directions).

[BlueMountain]

Step 4: Let go of the string. In this case the height seems to be 0.016, but some of the strings were over 0.030 off the fret. Use the appropriate nut file or saw to lower the slot until the string under full tension is about 0.007 to 0.010 above the fret.

This aspect of set-up still takes time, but it's worth it. I found that once I'd decided on the height I wanted the strings above the first fret, I could skip the first two steps given above. I still had to go through steps three and four every time I sawed the slot a bit more, zeroing the dial again and checking the height, but it paid off. When I'd finished the filing, thanks to the gauge, I couldn't easily see any space under any of the strings at the first fret (I wasn't wearing magnifying loupes, and 0.007 is not a very wide space), yet there was no buzzing at all. Of course, it was very easy indeed to fret strings at the first fret now, and it wasn't before.

So in brief, as far as I'm concerned, this gauge will make your customers so happy that it will pay for itself in referrals in no time. Or even if you do your own set-up work and only need to do this to one mandolin a year, it's worth it if you want your mandolin to play exceedingly well. (I'm assuming that your frets are level and dressed and that you've lowered your action at the bridge. If you haven't done that, you might want to aim at 0.010 at the first fret rather than 0.007.)

[250sc]

Stewmac's feeler guage is a lot cheaper and there is a lot less pulling strings out of the way when fileing the slots. Stack them to the same hight as the frets, hold it up against the nut and file the slot done till you touch the guage with the file.

http://www.stewmac.com/shop....es.html (http://www.stewmac.com/shop/Tools/Special_tools_for:_Nuts_and_saddles/Feeler_Gauges.html)

[Graham McDonald]

That seems like an overly complicated approach. Why not just push the string down between the 2nd and 3rd frets and lower the nut slot until the string just clears (by the thickness of a sheet of paper) the 1st fret. You should be just able to tap the string down and hear the 'tink'. If the string hits the 1st fret the nut is too low.

cheers

graham

[bryankimsey]

Why not just push the string down between the 2nd and 3rd frets and lower the nut slot until the string just clears

FWIW, that's how I do it. I then check the open strings with feeler gauges to make sure they're both even. At $5/set from my local auto parts store (wherever fine jumper cables are sold as Bussmann once said), I'm just happy I can still use gauges.

But, whatever works and produces the desired effect, I guess.

At Kaufman Kamp this year, I must've done 15-20 mandolin nuts and I started using a little probe I've had in my toolbox for years to lift the string from the nut slot. Worked great and saved my finger (esp. since I cut my index finger on a fret on Day 1).

[Paul Hostetter]

Wow, Bryan Kimsey's on this list now? Hooray!

[buddyellis]

Hey I was gonna say the same, previously, but didn't wanna feel like a fanboy http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

Anyway, welcome aboard Bryan!

[John Kasley]

Interesting jig. It immediately reminded me of my shop-made jigs for setting jointer and planer knives. Except in this case the direction of travel of the indicator is opposite from the knives in those machines. I'm guessing a lot of the cost of materials for this jig is in the dial indicator.

Since I already have a very good Starrett dial indicator and set of tips, I think I'll try and fabricate one of these next weekend. Shouldn't be too hard. Even a hardwood block should do, since the wood isn't going to expand/contract much during actual use.

I'm thinking it will be safer to mill the perpendicular grooves in a relatively large piece of stock, then drill holes for the dial micrometer, and finally cut the jigs out afterwards. (Keep the fingers well away from spinning bits).

I'm also thinking a small velcro strap to hold the jig in place, without compressing the fretboard, might be helpful.

Any thoughts from other members?