I'm having to seriously reconsider my design based on the fact that I can't find an aftermarket Bridge that will fit with what I want to do. All this thinking about bridges got me wondering about intonation. I'm sure someone will come up with some response to make me feel like this was a stupid question, but I can't figure this out. Why is the distance from the nut to the 12th fret not the exact same as the distance between the 12th fret and the saddle? For example: My SX fretless has been setup by me. The neck is pretty darn flat. There is a very small degree of relief. The intonation is set. So, I measure the distance from the nut to the 12th fret marker on the E and G strings. Both are 43cm. exactly. From the 12th fret marker to the string break at the saddles (as best as I can measure it) on the G string is 43.1 cm...pretty close...but on the E string its 44.1 cm. I don't get why? Is it string diameter...and if so isn't this going to effect intonation up the neck? Or does it have to do with equal temperment? And if I'm going to create a handmade bridge I'd like to be able to estimate with some degree of accuracy the measurements from the 12th fretmarker to the saddle. Is there any formula for this taking into account scale length and string diameter? Also, regarding my bridge...I've decided that I will create an Ebony bridge in the style of an Archtop guitar. My decision now is how to affix it to the bass. I could try to use barrels and thumb wheels to make it adjustable, but I'm not sure how to create the reversed threads in the wood. I'm also not sold on the coupling, if the bridge itself isn't actually sitting on the face of the bass. The other idea that I had was to simply bolt it to the face with removeable shims to adjust the height. Feedback?