I have sloooowly started work on my second build. My first build used a pre-built Carvin bolt-on neck, which was awesome, however this time around, I'd like to build the neck myself. I have the stewmac Japanese fretting saw, and have been building a 25.5" scale MDF template. I used a design I found on this site for a DIY fretting mitre box (which is such a neat idea... the Stewmac one is EXPENSIVE). Anyways... as I started cutting fret slots into the template, I realized just how difficult it was to freehand cut fret slots. I have been measuring with digital micrometer, and then using a square to create a line for my cut (.3mm pencil). I then use the Japanese fretting saw and try to cut exactly on the line removing the lead from the surface of the template and then deepening the cut. I realize there are quite a few areas that I could be making mistakes above, but my main question is:
How accurate do fret locations need to be for intonation? I went back and measured the first 7 cuts or so and here's what I've got (all are interval measurements):
1st fret 1.436 (ideal 1.431)
2nd fret 1.376 (ideal 1.351)
3rd fret 1.302 (ideal 1.275)
4th fret 1.225 (ideal 1.204)
5th fret 1.17s (ideal 1.136)
6th fret 1.078 (ideal 1.072)
7th fret 1.019 (ideal 1.012)
Perhaps worse is how straight the cut is (as dictated by the square)... For instance: 3rd fret is ~1.302 at top of fret and 1.282 at bottom of fret (worst one I measured - most appear to be within 30 thousandths).
I think at this point, I'm leaning towards chucking the template, and just buying the stewmac one, as painful as that is... but wanted to check your collective expertise for thoughts on this.
Kinda feels like an embarassing question, considering how careful I was trying to be... but I'm not afraid to be wrong, and would rather learn from it.
Thanks for the input!