Joe G’s PSH-1 First Build Diary

[McCreed]

I just measured my PRS1-TS (built 2018) and it's 312.5 to the centre of the 12th fret.
My bridge is set as per what Sonic & BD have said, and this guitar intonates as near to perfect as you can get.

[Joe Garfield]

I understand what you guys are saying and I appreciate the replies. Something still doesn’t make sense to me though. It might be that in practice, a few mm misplaced nut doesn’t make that big of a difference, since it gets split over 2 scale lengths and then adjust out as best as possible. I don’t have the experience to make that kind of call. But in theory, my nut is in the wrong place:

From the fretboard edge of the nut, it should be 1/2 of 24.75” or 1/2 of 628.65 mm to the center of the 12th fret which is 314.3 mm. Mine is 312mm. I understand I can move the neck such that the overall scale length is 628.5mm. If I do that, I’d need to adjust the saddles in a bit to get proper intonation. The result would be scale length technically a little short of 628.5 mm. But if I do that, it seems like every other note will technically be out of tune.

There are fret spacing tools/calculators. Here’s a pic of one from Stewmac. If I were building your own guitar and cutting frets, this would be my guide. This says from the fretboard edge to the center of the 1st fret should be 35.28 mm. My neck measures short of 34 mm. However all the other center-to-center fret spacings are pretty much spot on. Since every fret is in the right place relative to each other, but the nut is not in the right place relative to the 1st fret, it seems like gluing my neck based on the position of the first fret isn’t the best idea.

Does that make sense? Maybe I’m just over thinking a small difference? If your 12th fret doesn’t measure 614.25, but your guitar intonates well, how do other notes measure? For example, open G and 12th fret G are in tune, and open D and 12th fret D are in tune, then playing G on D string should also be in tune.

[Sonic Mountain]

I feel you are overthinking it. There are a lot of known issues with these kits and someone would have found this issue by now and you’d have more replies with fixes. If you go from the inside of the nut to the saddle on the high e (with it adjusted most of the way forward) you’ll be fine. All of the thicker strings will need adjustment back from the stated scale length, so ensure that’s available for the other strings.

[Simon Barden]

I'd run with what you have and take the scale length as 624mm.

If you put that in the StuMac calculator, then you get this:



If you look at your photo with the 12th fret and ruler, then the 10th fret position looks to match up with the calculated 273.8mm (though you could really do with a better ruler with individual, and thinner lined, mm markings, for this type of work.

You can measure a few other frets to confirm, but if they match, then I'd run with 624mm as the scale length and position the neck accordingly.

[Joe Garfield]

Thanks guys. Yeah I do overthink things quite a bit

If I compare the difference between 628.5 and 624 mm scale length fret spacing, the difference between each fret is like 1% (0.3mm at the first fret) which seems like it would be within reasonable tolerance. So maybe the nut is a little off but in the grand scheme of things its a very small amount.

That ruler is just for photos since it’s easy to see. I use much more accurate equipment (and also measure things in inches!) for things like this.

I’ll get going on fixing the neck to pocket fitting.

[Joe Garfield]

Some ‘after’ pics of the neck. I had to remove a TON (tonne?) of material from the bottom of the neck block, then level it, then square up the slot in the guitar and add shims. I’m really pleased with how it came out. It’s very satisfying.

Before:


After:

[Joe Garfield]

I forgot the tool pic . Mostly I just used a piece of window glass, double sided tape and sandpaper. Chalk to mark high spots. It’s hard to make a convex surface flat so I started removing material from the middle with the narrow sand paper side. Once it was slightly concave I used the wide side to make it flat. I don’t know how I knew that but it worked.

[Simon Barden]

Very nice work indeed!

Ton and tonne are almost exactly the same weight and both terms get used in the UK, though I'd imagine that tonne will be more prevalent amongst younger people and become more so.

[Joe Garfield]

Thanks Simon!

[Joe Garfield]

Ok, so I want to drill the holes for the pickup rings. But it would be nice if the neck was already glued on so nothing moves and I can align the pickup screws with the strings, and the edge of the pickup ring with the neck, etc. But I thought most people finish the guitar before gluing on the neck? Do you guys drill the pickup mount holes after finishing?