Neck Angle and Bridge Height

[Philip Secrist]

I am fitting the neck onto my 17-inch archtop guitar. I was shooting for a neck angle that would give me a 1-inch gap between a straight edge placed on the frets and the top at the bridge location. It turns out I am closer to 7/8 inch (maybe 3/32 shy of 1 inch). My bridge's lowest setting is 1-inch (without sanding down feet thinner). Do I need to take more off of the tang shoulders, or will I be OK? Haven't built enough yet to have a good feel for this yet. Thanks!

[Michael Lewis]

Remember the strings need some clearance above the frets! I think you should be good with those measurements. It is not uncommon to modify the bridge just to make it fit, let alone make it work well. What sort of bridge do you have? For archtops it seems that heavier bridges work better, but they (archtops) are all a bit different.

[Philip Secrist]

Hi Michael. It is a pre-made ebony bridge with thumb wheels for height adjustment purchased from Stewart MacDonald (I think it is adjustable up to 1 1/4").

[Chris Richards]

Hi Philip.....

I'm just about at the same stage, I followed the Benedetto book pretty closely apart from some aesthetic changes and with the 4-1/2 degree neck angle I ended up with a projected bridge clearance of a tad over 3/4 inch, I was a bit worried regarding the lack of downward pressure exerted on the bridge from the strings but the consensus of opinion was anything between 3/4 and 1 inch is considered ok. I too am going to use an adjustable bridge but will build my own. Rather than sand the feet you could instead cut/file the underside of the top half of the bridge to allow a lower adjustment, looking at the pictures on the Stewmac site there seems to be plenty of wood that could be removed.

[G.S. Monroe]

Bear in mind that string height will also change as you bring them up to tension. I once thought I had a good neck angle/bridge height like that, but once I brought the strings up to tuning tension the action had raised up another 1/2 inch. Yes the T-rod does mitigate some of that, but not always. Now I aim a bit lower on my neck angle.

[Rodger Knox]

I don't know much about archtops, but doesn't bringing it up to pitch lower the action by compressing the top?
Is there enough rotation of the neck/headblock due to string tension to change the action?

[Alan Carruth]

What happens to the action depends on the balance of forces in the guitar, and how stiff and strong it is. As you make more you'll probably find them to be reasonably consistent, but they might be a lot different from somebody else's.

The important things are the action height and the break angle over the bridge. Benedetto shows a six degree break angle, and that seems to be sufficient, despite what many flat top makers seem to feel. Its enough to keep the strings in contact with the saddle, so all the force of the vibration gets transmitted tot he top. Too high a break angle gives too much down force on the top. It kills the sound right away, and later kills the top.