This is about how I got round to inventing the string spacing gauges.
It all started a in 2011 when a ukulele that I had sold to a Guy down South..came back to me with a complaint
"And quite rightly so"... prior to this I more or less guessed the string positions by eye..He complained about the pitch of the strings at the nut which were not equal the "C "s string was about 1mm out...So I replaced the nut and this time made sure that the pitch was accurate..I did this with a scriber and six inch steel ruler...I marked out the two outer positions..Measured the distance between them..
it was 29.5mm and then divided that distance by 3 on the calculator and came up with a figure of 9.83mm
I then had to get a magnifier to read the rule so I could mark out the pitches as close as i could..in the end I did it but it was a lot of faffing about.... at the time I thought ! "to make sure I get no more complaints i'll have to get one of those nut marking rules that Ive seen in a Stewmac catalogue."
The the next day a brochure was posted through my letter box from a tool company....In one of the pages I spotted a tool called spider dividers..these were for marking out pitches for multiple joints in joinery and furniture making.
I thought ! wouldn't it be great is I could find a smaller version of one of these and I could use it just to mark out nuts and bridges and make life easier...I searched the web and couldn't find anything small enough to do pitches around 6mm.
So I set about designing one..and with the help of a retired draughtsman mate who did me a basic drawing we came up with the early four point prototype..I had to make all the parts out scrap in the garden shed...and waddaya know. it was rough but it did the job fine and I still use it today..I made a small batch of these and sent them out to one or two noted luthiers to get feedback..and all said it was a great device..and suggested that I go ahead and make more.
The whole story was recorded here on "The Ukulele Underground Forum"
http://www.ukuleleunderground.com/forum/showthread.php?57339-Nut-saddle-Gauge-for-4-string-
And further developments on a Six point version for the Guitar builders.
http://www.ukuleleunderground.com/forum/showthread.php?77028-The-Six-Pointer