
I’ve made an online tool for calculating nut layouts so that the spaces between the edges of the strings are equal – rather than measuring from the center of the strings: https://iko.kiwi/apps/nut_gen/
Well… The AI wrote it – in about 30 seconds… a couple of hours of aesthetic tweaking, and then 3 DAYS of fucking about trying to get it to work on the webserver (rather than my local machine), which I ultimately failed to do..
It was written in Python which Dreamhosts (the webserver company I use) should really have working out of the box, but (it transpires) they do not – so in the end it became clear that it’s going to take less time to just get an AI to translate it from Python to PHP than it is to try to set up a Python environment on Dreamhosts, so I did that. 15 seconds.
(although the elephant in the room here is that there’s actually no need to get an AI to write a program to generate guitar-nuts, when you can just ask and AI to generate them directly.)
Anyhoo… I did all this for a reason. This is the last bodgy prototype of the string-spacers before I start making stainless-steel versions.

The holes in the arms nearly double the number of measuring-points – and they allow far smaller measurements. It’s also occurred to me that if I offset them slightly, then they might be able to make nuts where the the strings are equally spaced from their edges rather than centres – but I wasn’t sure how much they’d err from the correct formulas, so I got the AI to write a program to figure it out. Results in the tables below.
Turns out that the variations from the correctly calculated values are really small – like 0.1 – 0.3 of a mm small… and that’s only if the size of the new nut is way bigger (55mm) than the average: 43mm…. and I think that is going to be pretty unusual.
So it turns out that the margin of error is actually less than what you’d get if someone used an unexpected string gauge.
Margins of error between precisely calculated values, and those from proportional calipers
default neck (43 mm) | 2.13 | 9.47 | 16.9 | 24.49 | 32.33 | 40.42 |
narrowest neck (35 mm) | 2.13 | 7.87 | 13.7 | 19.69 | 25.93 | 32.42 |
widest neck (55 mm) | 2.13 | 11.87 | 21.7 | 31.69 | 41.93 | 52.42 |
String spacings mm | 2.13 | 7.931 | 13.805 | 19.819 | 26.104 | 32.402 |
variance from correct mm | 0 | 0.069 | 0.105 | 0.128 | 0.174 | -0.018 |
inter string gap mm | 5.501 | 5.483 | 5.449 | 5.403 | 5.35 | |
Largest inter-string variance mm | -0.151 |
String spacings | 2.13 | 11.639 | 21.386 | 31.37 | 41.645 | 52.279 |
variance from correct | 0 | 0.231 | 0.314 | 0.32 | 0.285 | 0.149 |
inter string gap | 9.337 | 9.363 | 9.420 | 9.495 | 9.581 | |
Largest inter-string variance | 0.244 mm |
extra light | 2.1 | 9.31 | 16.61 | 24.05 | 31.67 | 39.52 |
heavy | 2.14 | 9.26 | 16.47 | 23.86 | 31.5 | 39.39 |
variance | 0.04 | -0.05 | -0.14 | -0.19 | -0.17 | -0.13 |
So there you go – mathematical proof of concept.
I’m getting 2 sets cut without the offset spacer holes… as there are 10 holes I think I’ll try to do them so they can accommodate 7-string guitars and basses as well.